Xllth INTERNATIONAL CONGRESS OF HEAD AND NECK RADIOLOGY October 6-9, 1991 Held under the patronage of the American Society of Head and Neck Radiology (ASHNR) and the European Society of Head and Neck Radiology (ESHNR) Honorary President: U. Fisch President: A. Valavanis Scientific Program Committee D.W. Chakeres, Columbus U. Salvolini, Ancona A.N. Hasso, Loma Linda P.M. Som, New York (Chairman) S. Larsson, Uppsala A. Valavanis, Zurich A.A. Mancuso, Gainesville G. Valvassori, Chicago E Phelps, London E Veillon, Strasbourg J. Vignaud, Paris

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International Congress of Head and Neck Radiology The first International Congress of Head and Neck Radiology (ICHNR) took place in Brussels, Belgium in 1958 upon the initiative of the founding members of the International Collegium of Radiology in Otorhinolaryngology. Upon 1985 this Congress has been held under the patronage of the Collegium. With the dissolution of the International Collegium of Radiology in Otorhinolaryngology in 1987 the ICHNR is now being held under the joint patronage of the American and European Societies of Head and Neck Radiology.

Past Congresses I.

II.

1958 Brussels (Belgium) President: R. Thienpont Secretary: C. Chauss6 1959 Milan (Italy) President: P.L. Cova Secretary: L. Agassi

II1.

1963 Bordeaux (France) President: M. Portmann Secretary: G. Guillen

IV.

1967 Acapulco (Mexico) President: R. Ruenes Secretary: J.R. Carvajal

V.

1970 Wtirzburg(Gerrnany) President: H. Wullstein Secretary: M. Trujillo-Peco, G. Guillen

V1.

1973 Santiago de Compostela (Spain) President: M. Trojillo-Peco Secretary: V.G. Queimadelos

VII.

VIII.

IX.

X.

1976 Copenhagen (Denmark) President: S. Briinner Secretary: P. Andersen 1979 New Orleans (USA) Joint Meeting International Collegium of Radiology in ORL President: G. Valvassori Secretary: E. Palacios American Society of Head and Neck Radiology President: D.H. Johnson Secretary: W.N. Hanafee 1982 Fontevraud (France) President: J. Vignaud Secretary: G. Guillen, H. Wilbrand 1985 Caracas (Venezuela) President: E. Chiossone Secretary: C. Gonzalez (This Congress was cancelled)

XI.

XII.

1988

Uppsala (Sweden) President: H. Wilbrand Secretary: G. Guillen

1991 Zurich (Switzerland) Honorary President: U. Fisch President: A. Valavanis Secretaries: P. Som and S. Larsson

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American Society of Head and Neck Radiology The American Society of Head and Neck Radiology (ASHNR) was founded in Chicago, Illinois on November 12, 1976. The Society was incorporated under the laws of Louisiana on March t8, 1977 and sponsored the first postgraduate course on Radiology in Otolaryngology and Ophthalmology in Los Angeles in May 1977, assuming sponsorship of the annual course on the same subject held under the anspices of Doctor G. Valvassori for ten years in Chicago. The following purposes of the Society were adopted by its founding members: 1. 2. 3. 4. 5.

To To To To To

stimulate interest and advance knowledge in the field of Head and Neck Radiology foster continuing development of head and neck radiology as an art and a science improve methods of teaching radiologic diagnosis of disease of the head and neck provide meetings for presentation and discussion of papers promote the dissemination of knowledge in head and neck radiology

The ASHNR currently has over 300 members. Active membership is open to physicians who practice radiology in North or South America and who are certified in general radiology by the American or Canadian Boards of Radiology, or a comparable certifying organization. Associate membership is open to physicians who practice radiology in a country other than one located in North or South America and who are certified in general radiology by an organization comparable to the American or Canadian Boards of Radiology.

Founding Members William N. Hanafee, Los Angeles Daniel H. Johnson, Jr., New Orleans Guy D. Potter, New York Galdino E. Valvassori, Chicago

Past Presidents Robert L. Scanlan Judah Zizmor Barbara L. Carter R. Nick Bryan Dexter W. Johnson

Katherine A. Shaffer R. Thomas Bergeron Peter M. Sore Anthony A. Mancuso

President Ira F. Braun

Secretary Donald W. Chakeres

Past President Anthony A. Mancuso

President-Elect Mahmood E Mafee

Treasurer Hugh D. Curtin

Member-at-large Charles J. Schatz

Vice President William P. Dillon

Rules Committee Chairman Barbara L. Carter

Galdino E. Valvassori William N. Hanafee Guy D. Potter Daniel H. Johnson, Jr. Kenneth D. Dolan

Executive Committee 1991-92

Past and Future Meetings 1st- 10th 1 lth 12th 13th 14th 15th 16th 17th 18th

Novembe~ 1976 Novembe~ 1977 May, 1978 May, 1979 May, 1980 May, 1981 Jun~ 1982 May, 1983 May, 1984

Chicago, IL Los Angeles, CA New York City New Orleans Palm Beach, FL Los Angeles, CA Fontevraud, France Boston, MA San Antonio, TX

Galdino E. Valvassori William N. Hanafee Guy Potter Daniel H. Johnson, Jr. Kenneth D. Dolan Robert L. Scanlan Judah Zizmor Barbara L Carter R. Nick Bryan Donald W. Chakeres, Co-Dir

S18 19th 20th 21st 22rid

May, May, June, May,

1986 1987 1988 1989

Seattle, WA Milwaukee, WI Uppsala, Sweden Toronto, Canada

23rd

May, 1990

New Orleans, LA

24th 25th

April, 1991 April, 1992

Boston, MA Chicago, IL

Dexter W. Johnson Katherine A. Shaffer R. Thomas Bergeron Peter M. Som Edward E. Kassel, Co-Dir Anthony Mancuso Daniel H. Johnson, Co-Dir Ira F. Braun Mahmood E Mafee

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European Society of Head and Neck Radiology The European Society of Head and Neck Radiology (ESHNR) was founded on January 22, 1987 in Antwerp, Belgium during a constitutional meeting held under the chairmanship of Professor Hermann Wilbrand, Uppsaia. The following purposes of the Society were unanimously adopted by the 20 founding members: 1. 2. 3. 4. 5. 6.

To advance knowledge in the field of head and neck diagnostic radiology, interventional radiology and diagnostic imaging To stimulate interest in the field of head and neck radiology To promote research in head and neck radiology To improve methods of teaching radiologic diagnosis of diseases of the head and neck area To provide meetings for the presentation of papers and the dissemination of knowledge To foster the continuing development of head and neck radiology as a science

Membership in the ESHNR is open to any qualified individual of high professional reputation who has made significant contributions to head and neck radiology and/or who devotes a significant portion of his/her time to the study of diseases of the head and neck area. There are presently 119 members of the ESHNR.

Founding Members B. Appel, Belgium S. Brt~nner, Denmark A. Chiesa, Italy E. Claus, Belgium G. Corn61is, Belgium H. Damsma, The Netherlands U. Fisch, Switzerland

C. Guirado, Spain S. Larsson, Sweden G. Lloyd, United Kingdom P. Phelps, United Kingdom K. Reisner, Germany O. Schubiger, Switzerland U. Salvolini, Italy

M. Trujillo-Peco, Spain A. Valavanis, Switzerland E Veillon, France J. Vignaud, France P. van Waes, The Netherlands H. Wilbrand, Sweden

Executive Committee 1990-1991 President Klaus Reisner

Secretary Peter Phelps

Vice-President Antonio Chiesa

Treasurer Nicole Freling

Members at large Glyn Lloyd Manuel Trujillo-Peco Jacqueline Vignaud Hermann Wilbrand

President Elect Anton Valavanis

Boards and Committees Electoral Board 1990/91

Scientific Committee 1990/91

Secretary: Italy: United Kingdom: Spain: France: Germany: Austria and Switzerland: Benelux: Scandinavia:

Secretary: Italy: United Kingdom: Spain: France: Germany: Austria: Switzerland: Benelux: The Netherlands:

S. Larsson A. Chiesa G. Lloyd C. Guirado J. Vignaud T. Vogl O. Schubiger S. Lemahien S. Larsson

E VeiUon U. Salvolini P. Phelps C. Guirado C. Jardin M. Lenz N. Gritzmann A. Valavanis B. Appel J. Castelijns

Board of Representatives of the Society to the Homelands 1990/91

Italy: Spain: Switzerland: Belgium: Denmark: Portugal: Greece: United Kingdom: Germany: Austria: The Netherlands: Sweden: France: Hungary:

A. Chiesa C. Guirado A. Valavanis S. Lemahien S. Brtinner E Torrinha P. Dimopoulos G. Lloyd K. Reisner G. Canigiani H. Damsma H. Wilbrand J. Vignaud J. Kenesz

S 20

Past Meetings 1st Meeting (Founding Meeting) 1987, Antwerp President: H. Wilbrand 2nd Meeting (in conjunction with Xlth International Congress of Head and Neck Radiology) 1988, Uppsala President: H. Wilbrand

3rd Meeting (in conjunction with 17th International Congress of Radiology) 1989, Paris President: J. Vignaud

5th Meeting (in conjunction with XlIth International Congress of Head and Neck Radiology) 1991, Zurich President: A. Valavanis

4th Meeting 1990, Brescia President: A. Chiesa

Future Meetings 6th Meeting 1992, Karlsruhe President: K. Reisner

7th Meeting 1993, Barcelona President: C. Guirado

8th Meeting (in conjunction with XIIIth International Congress of Head and Neck Radiology) 1994, Washington D.C.

$21

Postgraduate Course in Head and Neck Radiology October 6-7, 1991 Course Directors Sven G. Larsson, M.D. Department of Diagnostic Radiology University Hospital Uppsala, Sweden Peter M. Som, M.D. Professor of Radiology and Otolaryngotogy Chief, Head and Neck Radiology The Mount Sinai School of Medicine of the City University of New York New York, N.Y., USA

Faculty Pierre Bourjat, M.D. Professor of Radiology Service de Radiologie I-Hospital Central C.H.U. Strasbourg, France

Martin Lenz, M.D. Department of Diagnostic Radiology Technical University of Munich Klinikum rechts der Isar Munich, Germany

Barbara L. Carter, M.D. Professor of Radiology and Otolaryngology Tufts School of Medicine Chief, ENT Radiology New England Medical Center Boston, /VIA, USA

William W.M. Lo, M.D. Clinical Professor of Radiology University of Southern California Department of Radiology St. Vincent Medical Center Los Angeles, CA, USA

J.A. Castelijns, M.D. Free University Hospital Amsterdam, Netherlands

Robert B. Lufkin, M.D. Associate Professor of Radiology UCLA Medical Center Los Angeles, CA, USA

Donald W. Chakeres, M.D. Associate Professor of Radiology Head of Neuroradiology Clinical Director of MRI Ohio State University Columbus, OH, USA Antonio Chiesa, M.D. Professor and Chairman Department of Radiology Spedali Civili Brescia, Italy William P. Dillon, M.D. Associate Professor of Radiology and Neurology UCSF School of Medicine San Francisco, CA, USA William N. Hanafee, M.D. Professor of Radiology UCLA Medical Center Los Angeles, CA, USA

Mahmood E Mafee, M.D. Professor of Radiology University of Illinois at Chicago Director of Radiology Section Eye and Ear Infirmary Director MRI Center Chicago, IL, USA Anthony A. Mancuso, M.D. Professor of Radiology University of Florida College of Medicine Gainesville, FL, USA Peter D. Phelps, M.D. Royal National Throat, Nose and Ear Hospital London, United Kingdom Guy D. Potter, M.D. Professor of Clinical Radiology Columbia University Attending Radiologist St. Lukes-Roosvelt Hospital Center New York, NY, USA

Deborah L. Reede, M.D. Adjunct Associate Professor of Radiology New York University School of Medicine New York, N.Y. Associate Professor of Clinical Radiology SUNY Health Science Center Vice Chairman of Radiology The Long Island College Hospital Brooklyn, NY, USA Peter M. Som, M.D. Professor of Radiology and Otolaryngology Chief Head and Neck Radiology The Mount Sinai School of Medicine of the City University of New York New York, NY, USA Mutsumasa Takahashi, M.D. Professor and Chairman Department of Radiology Kumamoto University School of Medicine Kumamoto, Japan Galdino E. Valvassori, M.D. Professor of Radiology and Otolaryngology University of Illinois Chicago, IL, USA Francis Veillon, M.D. Service de Radiologie I-H6pital Central Strasbourg, France Thomas Vogl, M.D. Radiologische Klinik der Universit~it Miinchen Munich, Germany

S 22 Alfred L. Weber, M.D. Professor of Radiology Harvard Medical School Chief of Radiology Massachusetts Eye and Ear 'Infirmary Boston, MA, USA

Hermann Wilbrand Professor of Radiology Department of Diagnostic Radiology University Hospital Uppsata, Sweden

Per-Lennart Westesson, M.D. Department of Diagnostic Radiology University Hospital Lurid, Sweden

Robert A. Zimmerman, M.D. Professor of Radiology Children's Hospital of Philadelphia Philadelphia, PA, USA

James Zinreich, M.D. Assistant Professor of Radiology Division of Neuroradiology The Johns Hopkins Medical Institutions Baltimore, MD, USA

S 23

Postgraduate Course in Head and Neck Radiology Morning Session Chairman: W. Hanafee, Los Angeles, USA 09.30 a m - 10.00 a m

CT of the nasal cavity and paranasal sinuses for endoscopic sinus surgery S.J. Zinreich, Baltimore, USA

10.00 a m - 10.30 a m

Facial Fractures P. Bourjat, Strasbourg, France

10.30 a m - 11.00 a m

Coffee Break

11.00 a m - 11.45 a m

Sinonasal Disease P.M. Som, New York, USA

11.45 a m - 12.30 p m

MR Imaging with Gd-DTPA in Lesions of the Naso- and Oropharynx T. Vogl, Munich, Germany

12.30 p m - 0 1 . 0 0 p m

The Pharynx and Oral Cavity W.P. Dillon, San Francisco, USA

01.00 p m - 0 2 . 0 0 p m

Lunch

CT of the nasal cavity and paranasal sinuses for endoscopic sinus surgery S.J. Zinreich, M.D. Neuroradiology Division of the Russell H. Morgan Department of Radiology and Radiologieal Science, the Johns Hopkins Medical Institutions, Baltimore, Maryland, U S A The diagnostic evaluation and treatment of sinus disease is undergoing a major evolution. Changes are being brought about by a better understanding of the pathophysiology of sinus disease, advances in diagnostic techniques and endoscopic instrumentation, and the introduction of endoscopic surgery. Standard paranasal sinus roentgenograms can readily demonstrate maxillary and frontal sinus disease but their accuracy is highly variable in demonstrating the presence and extent of ethmoid sinusitis. From a radiographic as well as a clinical perspective it is easy to understand the otolaryngologist's primary focus on disease in the frontal and maxillary sinuses. Several noted otolaryngologists including Messerklinger, Proctor and Hilding pointed out that the ethmoid sinus is most commonly affected by inflammatory disease, and infection here is probably the precursor of disease in the frontal and maxillary sinuses. Proctor

in 1966 reported that "the ethmoid sinuses are usually the key to any problem involving infectious sinusitis. Infection begins there and persistent infection there is usually the reason for failure of therapy directed at any o f the other paranasal sinuses". Later Messerklinger and Drettner demonstrated that obstruction of the ostia is the usual precursor to sinusitis. They showed that apposition of contiguous mucociliary surfaces within the paranasal sinuses results in a disruption of sino-nasal drainage, with retention of secretions, which in turn leads to inflammation and infection. Messerklinger also demonstrated that the infundibulum and the middle meatus are the channels most frequently affected by anatomic variations which may also result in juxtaposition of the mucosal surfaces in the narrow ostiomeatal channels, and in turn facilitate mucosal inflammation. Aust and Drettner also demonstrated a high frequency of

S 24 ostiai dysfunction in subjects with a history of recurrent maxillary sinusitis, and reported that maxillary ostial patency is almost always reduced in patients with chronic sinusitis. The development of new endoscopic instruments and associated surgical techniques are providing a new surgical approach for treating chronic sinusitis. This surgery is aimed at restoring normal physiology by reestablishing normal mucociliary drainage and ventilation of the sinuses, a procedure coined by Kennedy as "functional endoscopic sinus surgery". The surgery is primarily directed to remove localized disease obstructing the ethmoid air pathways. For this purpose, a detailed preoperative display of the nasal cavity, paranasal sinuses, and adjacent regional anatomy is critical. Unfortunately the use of standard roentgenograms precludes an accurate evaluation of the anterior ethmoid sinus. Furthermore, the convoluted anatomic framework of the ethmoid cells precludes the direct non-invasive en-

doscopic evaluation of deeper ostiomeatat, posterior ethmoid and sphenoid sinus disease These issues are largely addressed by using coronal CT scanning of the nasal cavity and paranasal sinuses, an evaluation strongly complemented by diagnostic endoscopy. The role of CT in the evolving nasal and paranasal sinus endoscopic evaluation and surgery is to: display the regional anatomy and important anatomical relationships; identify anatomic variations which might predispose blockage of the ostiomeatal passages and therefore repeated bouts of sinusitis; display those anatomic areas that are inaccessible to the endoscopic instrumentation; and to guide the endoscopist during surgery to the site of disease and aid her/him in order to avoid complications. In recurrent acute sinusitis, CT should be delayed until medical treatment has controlled the acute manifestations.

Facial Fractures P. Bourjat Department of Radiology, University of Strasbourg, France Maxillofacial trauma is a common clinical and radiological problem. Most fractures involve the nasal bones and the mandible. These fractures are usually well seen by plain films and by panoramic tomography. Therefore CT is rarely indicated for these fructures. For all other facial fractures and most associated soft tissue injuries CT continues to be the best imaging study. MR has a complementary role in specific situations. The best time to examine patients for facial fractures may vary, depending on the clinical status of the patient, the type of facial injurs; and the time within surgical correction should be performed. Mostly immediate surgery is not necessary, and primary reduction and fixation of fractures can be delayed up to 6 or 8 days after trauma, when hematoma and edema have decreased. Some situations require immediate surgical treatment and therefore immediate radiologic imaging: compression of the optic nerve with visual decrease, posttraumatic exophthalmos by intraorbital hemorrhage, hematoma in the nasal septum. For imaging the maxillofacial skeleton by CT it is optimal to have two complementary planes: axial and direct coronal. If direct coronal imaging may be impossible, multiplanar image reformation can obtain coronal or sagittai planes. Currently facial fracture evaluation does not necessarily require the most sophisticated high-resolution CT equipment and 1 or 1.5 mm sections. 3 to 5 mm sections can be quite adequate if reformation is not necessary. Threedimensional reconstruction is sometimes able to give a spatial information about complex fractures and displacement of some fragments.

MR contributes particularly for evaluation of associated soft tissue and extrafacial injuries. Because of its multiplanar imaging capabilities without having to move the patient, and the excellent soft tissue visualization, MR is superior to CT for evaluation of orbital "blow-out" and "blow-in" fractures, intraocular and intraorbital hemorrhage, and intracranial injuries. The imaging studies should identify all fractures, determine the direction and degree of displacement, provide a classification of fracture types, determine the level of facial instability to define surgical fixations, and detect the associated soft tissue injuries. The four main fracture groups are: • trimalar fracture, • Lefort transfacial fractures, • frontoethmoidal fractures, • solitary orbital fractures. Most commonly soft tissue injuries involve the oculomotor muscles. The motility impairment results from different mechanisms. CT reformation or MR in the oblique-sagittal plane should demonstrate the nature of entrapment, amount of herniated orbital fat, and scar tissue formation. Most foreign bodies are metallic, and CT imaging can identify their size and position. Posttraumatic compromise of lacrymal and frontonasal drainage pathways may also be identified by CT. The final discussion deals with the results of MR versus high-resolution CT for management of facial fractures, and with the advantages of each technique.

Sinonasal Disease P.M. Som The Mount Sinai Medical School of Medicine of the City University of New York, New York, USA The most common diseases that involve the sinonasal cavities are inflammatory in nature. Such disease is ubiquitous and is

usually of a viral or bacterial etiology. The most common radiographic study performed today on patients who present with

$25 symptoms of inflammatory type disease is probably still the plain film series. When should the radiologist inform the clinician that sectional imaging should be performed? Is, in fact, it better to no longer perform plain film studies and only obtain CT or MRI examinations? Our experience is that for the vast majority of patients with acute inflammatory disease, the plain film examination is an excellent survey study that is inexpensive and has a low radiation dose. It provides good mapping of the patient's disease. However, if the patient has chronic symptoms or the surgeon is contemplating surgery, noncontrast CT should be obtained. Such a study provides the best evaluation of the presence and severity of any soft tissue disease within the sinuses and nasal cavities and demonstrates any bone erosion or remodelling. MRI performed on patients with histories of chronic inflammatory disease will nicely demonstrate any acute disease. However, if there are chronic, dessicated secretions they can go undetected. It is because of this that CT is suggested as the examination of choice in such patients. The degree of dehydration and the protein content of the sinonasal secretions alters the T1- and T2-weighted signal intensities of these secretions. In fact, the T1- and T2-weighted signal intensities can be used to estimate the protein content of collections of physiologic macromolecular protein solutions. The primary diagnostic imaging problem is that at present the very proteinaceous, dessicated secretions give signal voids which cannot be differentiated from those of either air or the mycetomas associated with fungal disease. Thus, a totally filled sinus with such material will appear opacified on CT, but may erroneously look partially or totally aerated on MRI. Tumors of the sinonasal cavities are overall rare, representing only about one percent of all tumors in the body. As a

group, these tumors are highly cellular, aggressive lesions that have low-to-intermediate Tl-weighted and slightly higher intermediate T2-weighted signal intensities. Because acute inflammatory secretions are 95 percent water, they have low T I weighted and high T2-weighted signal intensities. Thus, about 95 percent of sinonasal tumors can be distinguished from acute inflammatory disease on T2-weighted MRI. Only a few tumors, such as some minor salivary gland neoplasms have sufficient amounts of serous and mucinous secretions (water) to have high T2-weighted signal intensity. CT contrast material may be helpful in distinguishing tumor margins from adjacent inflammatory or normal tissues. However, the use o f contrast material with MRI has mixed blessings, because the tumor will usually enhance, but so will inflammed mucosa and in some instances normal mucosa. Thus, the most accurate assessment of tumor size is often made on noncontrast MRI rather than on post-contrast studies. MRI contrast studies appear to be most vaIuable when used to evaluate tumor extension through the skull base. With regard to bone erosion, large areas of destruction are well seen on either CT or MRI. However areas of focal bone erosion, especially if there is adjacent mature scar tissue from prior surgery, are better evaluated on CT than on MRI. Lastly, because granulation tissues, chronic secretions, blood, and tumor may all have similar MRI signal intensities, caution must be the rule when mapping tumor margins or when assessing the presence of recurrent tumor in post-treatment patients. All of these concepts will be reviewed and illustrated with case material.

MR Imaging with Gd-DTPA in Lesions of the Nasoand Oropharynx Th. Vogl, S. Dresel, J. Lissner Department of Radiology, University of Munich, Germany Introduction Magnetic resonance imaging (MR) is being used with increasing frequency in the evaluation of patients with head and neck disease. In the region of the naso- and oropharynx, MR has shown that its superior soft tissue contrast resolution depicts tumor margins and differentiates inflammatory changes from solid space-occupying lesions more accurately than computed tomography does. Not only the exact topographic relations, but also the vascular supply and the degree of vascularisation are essential for the preoperative diagnosis. With introduction of the paramagnetic contrast medium Gd-DTPA the advantages of MR might improve even further. Material and methods 485 patients were examined. The patients were suffering from different malignant and benign tumors of the nasopharynx, paranasal sinuses and nasal cavity. The most important malig-

nant tumors were epithelial tumors, like squamous cell carcinomas, adenocarcinomas, adenoid-cystic carcinomas, esthesioneuroblastomas and nonepithelial tumors like osteogenic sarcomas, rhabdomyosarcomas, reticular cell carcinomas, chondrosarcomas and lymphomas. The most commonly found benign tumors were nonodontogenic tumors like papillomas, granulomas, juvenile angiofibromas, osteomas and fibrous lesions as well as odontogenic tumors like dentigerous and radicular cysts and ameloblastomas. MR images were obtained with a 1.0 T superconducting imaging system (Siemens Magnetom) in transverse, coronal and sagittal planes. Tl-weighted sequences with TR = 500 ms and TE = 25 ms and T2-weighted sequences with TR = 1600 ms and TE = 25/90 ms were used before and after application of the contrast medium Gd-DTPA. CT studies were made on a Siemens Somatom 2 or DRH with nonionic contrast-agent. The studies were categorized using a grading system with range of grades from unsatisfactory (grade 0) to optimal (grade 3).

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Results

Nasopharynx The anatomical structures like pharyngeal recess, levator and tensor veli palatini muscle and pharyngobasilar fascia were better identified after Gd-DTPA, because sharper contrast was achieved between these structures and adjacent tissues. The nasal mucosa and turbinates often got very bright on enhanced MR. Therefore, it might be difficult to completely delineate an enhancing tumor if it is contiguous with the nasal cavity. All primary tumors of the nasopharynx showed an infiltration of the levator and tensor veli palatini muscles and of the phar)aagobasilar fascia. Unsharp margins and necrotic areas were characteristic and often found in these nasopharyngeal tumors. This was best seen on Gd-DTPA enhanced images. 9007o of these patients showed fluid in the mastoid sinuses, because of eustachian tube obstruction, best seen on T2-weighted images. A discrete crossing of the midline by the tumor could be seen on the contrast-enhanced images, but could be suspected on the preenhanced images. In some cases, even after Gd-DTPA, it was difficult to judge whether the tumor crossed the midline or not. Subtraction technique was particularly helpful in such situations. Gross infiltration of the longus cotli muscle was well demonstrated on the enhanced MR, but was also well shown on the proton density images. However, subtle extension of tumors to the pterygoid muscles could be judged best on images with GdDTPA enhancement. A further advantage of contrast MR was the discrimination between solid tumor and fluid containing cysts. It was sometimes not possible to decide on the basis of the T2-weighted image whether it was a tumor with homogeneous high signal intensity or a cyst. After Gd-DTPA application the cyst did not enhance in the Tl-weighted image, only the thin cyst wall became brighter. Another important differential diagnosis, especially in young patients, was the differentiation between lymphoid hyperplasia and any kind of lymphoma. In the plain TI- and T2-weighted images there was no difference visible in the pattern of the tumor. After Gd-DTPA the lymphoid hyperplasia showed septations in its internal pattern. The lymphoma did not enhance as much as lymphoid hyperplasia and its inner structure was more homogeneous. In secondary tumors of the maxillary sinuses it was difficult to see early involvement of the small bony walls in both plain and Gd-DTPA enhanced images. This was seen better on CT.

Oropharynx In all cases MR imaging after administration of Gd-DTPA proved to be diagnostically advantageous. Using a ratio of the signal intensity values before and after Gd-DTPA the ratios for normal muscle and fat in the Tl-weighted sequences showed a range between 1.27 and 1.35, with values fbr untreated carcinomas at the level of 1.95. The specific vascularisation of each tumor and the degree of vascular intima damage led to different uptake patterns in the perivascular spaces. For the accurate classification of malignant tumors of the base of the tongue it was essential to be able to judge the extension across the midline. Extension to the vallecula, preepiglottic space or tonsillar bed usually requires partial pharyngectomy and laryngectomy for

the mass to be resected completely. Noncontrast MR images allowed to delineate tumors in some cases and the degree of infiltration of soft tissues could be demonstrated. Gd-DTPA enhanced imaging improves the contrast further. Also the pharyngeal mucosa showed a shortened longitudinal relaxation time and became bright. The administration of Gd-DTPA gave significant additional information in 72°70 of the patients with oropharyngeal lesions. The information was either on deep extension of the tumor or on the submucosal spread. In the tongue, a significant enhancement of the intrinsic muscles was found after Gd-DTPA, whereas the extrinsic muscles showed less enhancement. The interpretation of the characteristic changes in signal intensity after Gd-DTPA was important for the diagnosis of tumors of the base of the tongue and the floor of the mouth. The increase o f signal intensity enabled also the delineation of lymph nodes with a diameter as small as 4 ram.

Conclusion MR in combination with Gd-DTPA shows significant advantages for diagnosing lesions of the head and neck. But the advantages of non-invasive investigation are cancelled out. Thus, the use of Gd-DTPA has to be determined critical for every single area of the head and neck. The diagnostic procedure in tumors of the nasopharynx requires exact demonstration of the complex anatomy in order to define the extension into the middle cranial fossa and deep structures. Only the contrast medium enhanced MR allows an exact differentiation of small anatomical details, such as demonstration of both palatini muscles and the pharyngobasilar fascia. The accurate relationship to vessels and nerves (V, VII, IX) can be best demonstrated on Gd-DTPA enhanced images. Both plain and Gd-DTPA MR is inferior to CT in showing cortical bone detail. CT yields better resolution of bony structures. If the tumor shows an area of hemorrhage at a stage when it is very bright on the Tl-weighted plain image, after Gd-DTPA the tumor will enhance but the hemorrhage will not. Therefore, it may be difficult to differentiate between solid tumor and hemorrhage after Gd-DTPA administration. Furthermore, in the oropharynx and tongue area MR is superior to CT in detecting soft tissue lesions. MR is especially useful for showing malignant tumors, such as carcinomas. GdDTPA prevents overestimation of tumor size in this area and the enhancement allows an exact delineation of borderline cases. Generally, the administration of Gd-DTPA improves the determination of tumor extent in the base of the tongue, the pharyngeal wall, palate and the floor of the mouth. For distinguishing between malignant and noninvasive masses, the contrast medium proves to be helpful, but the treatment planning is based upon morphological criteria of the tumor. Fatty involution after paresis and cysts do not enhance and thus are easily differentiated from tumors. The advantages of MR with Gd-DTPA in diagnosing lesions of the naso- and oropharynx are the better delineation of tumors, the early detection of infiltrations and the possibility of improving differential diagnostic considerations. MR with GdDTPA is an improved diagnostic tool in rapidly confirming clinical suggestions.

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The Pharynx and Oral Cavity W.P. Dillon UCSF School of Medicine, San Francisco, California, USA Examination of the pharynx and oral cavity is best performed by CT or magnetic resonance (MR) imaging. MR imaging offers greater soft tissue contrast resolution than CT and is particularly useful for the evaluation of the extent of neoplasms within the upper aerodigestive tract. CT scanning, while capable of imaging primary tumors as well as adenopathy, offers an advantage over MR in the evaluation of the osseous structures of the upper head and neck. The two can be sometimes used in conjunction to evaluate lesions which require both excellent soft tissue contrast as well as bony detail. My personal preference is to utilize MR scanning for the oral cavity and nasopharynx in patients who have neoplasms. MR offers better detection of tumor volume, radiation and chemotherapy changes, and with new fat saturation techniques, contrast agents can be utilized as efficiently as with CT. The primary pathologies involving the pharynx and oral cavity are neoplastic. Most of these neoplasms are benign papillomas which rarely require imaging. The majority of neoplasms which arise in the upper aerodigestive tract are biopsied prior to diagnostic imaging with fine needle aspiration techniques. Therefore, histology is generally known and our role as imagers is to map the extent of the disease and detect nonpalpable nodes. This can be accomplished by either CT or MR, but I prefer MR for this issue. MR provides an advantage over CT in the evaluation of tumor relationship to carotid artery. The latter is important when resection of the lesion is contemplated. MR or ultrasound are more reliable than CT in excluding involvement of the carotid artery. No technique is specific in detecting tumor invasion into the carotid artery. The detection and specificity of MR and CT in the evaluation of lymph nodes is controversial. Contrast enhanced CT

provides more specificity over noncontrast MR. Inhomogeneously enhancing nodes and peripherally enhancing nodes are presumed malignant or infectious on CT. These nodes may look similar to reactive nodes on MR. The use of MR contrast agents often does not help; these nodes are often embedded within fat and, therefore, enhance to a similar intensity to surrounding tissues. The recent evolution of fat saturation techniques in which the fat is turned black on Tl-weighted images provides "CTlike" images of great clarity. Further study with regard to detection of nodal disease is underway.

Suggested readings Harnsberger HR et al. (1987) Seminars in Ultrasound, CT and MR, Vo! 8, No 3. Cranial Nerve Imaging, September Harnsberger HR et al. (1986) Seminars in Ultrasound, CT and MR, Vol 7, No 2. Extracranial Head and Neck Imaging, June Mancuso AA et al. (1984) The Upper Aerodigestive Tract. In: Bergeron RT, Osborn AG, Sore AM (eds) Head and Neck Imaging Excluding the Brain. St Louis, MO, pp 374-401 Hardin CW, Harnsberger HR, Osborn AG et al. (1985) Infection and Tumor of the Masticator Space: CT Evaluation. Radiology 157:413-417 Dillon WP, Mills C, Kjos Bet al. (1984) Magnetic Resonance Imaging of the Nasopharynx. Radiology 152:731-738 Harnsberger HR, Dillon WP (1985) CT Evaluation of Muscular Denervation Atrophy Patterns in the Head and Neck. Radiology 155:665 -670 Mancuso AA, Hanafee W (1988) Computed Tomography and Magnetic Resonance Imaging of the Head and Neck, second edition. Williams and Wilkins

S 28

Postgraduate Course in Head and Neck Radiology Afternoon Session Chairman: H. Wilbrand, Uppsala, Sweden 02.00 p m - 02.30 pm

Cystic Lesions, Benign and Malignant Tumors of the Mandible and Maxilla A.L. Weber, Boston, USA

02.30 p m - 0 3 . 0 0

Imaging the Parapharyngeal Space R.B. Lufkin, Los Angeles, USA

pm

03.00 pm-03.30 pm

Salivary Glands B.L. Carter, Boston, USA

03.30 pm-04.00 pm

Coffee Break

04.00 pm-04.30 pm

Laryngeal Anatomy J.A. Castelijns, Amsterdam, The Netherlands

04.30 pm-05.15 pm

Laryngeal Cancer and Staging of Cervical and Retropharyngeal Lymph Node Metastases A.A. Mancuso, Gainesville, USA

05.15

Neck Vessels - Anatomy and Pathology D.W. Chakeres, Columbus, USA

pm -

05.45

pm

Cystic Lesions, Benign and Malignant Tumors of the Mandible and Maxilla A.L. Weber Harvard Medical School, Massachusetts eye and ear infirmary, Boston, Massachusetts, U S A Cystic lesions and benign and malignant tumors of the mandible and maxilla represent a large group of diverse lesions that are easily demonstrated with different radiological imaging modalities, such as intraoral dental films, conventional views of the mandible (anteroposterior, lateral, and oblique views, and panoramic X-rays) Computerized Tomography (CT), and Magnetic Resonance Imaging (MRI). Cysts and benign tumors are easily recognized on conventional films and, in some cysts, a radiologic diagnosis can be established. Large cysts, and aggressive benign and malignant lesions, however, should be further assessed with CT and MRI. For detailed analysis of the relationship of some lesions to a tooth, intraoral dental films are utilized. CT is especially well suited for demonstrating bony abnormalities in the mandible and maxilla and evaluating the adjacent soft tissue structures. The CT examination should include:

1) bone and soft tissue window settings, 2) 2 - 5 mm axial sections parallel to the inferior bony margin of the body of the mandible from the level of the temporomandibular joint to the hyoid bone, and 3) 4 mm coronal sections from the external auditory canal to the anterior margin of the symphysis of the mandible perpendicular to the orbitomeatal line. MRI has limited application in the evaluation of mandibular cystic lesions and benign tumors. It may provide information in the characterization of the cyst content, such as fluid, keratin, and blood. MRI may also be helpful in differentiating a cyst from a solid tumor, reflected by different signal intensities. CT, with bone window setting, is especially indicated for analyzing bony abnormalities, such as expansion, bone destruction, and for demonstrating calcifications, cementum, and osteoid within the various lesions. Soft tissue boundaries of

S 29 cysts and tumors outside the mandible, however, are better defined with MRI. On the magnetic resonance image, a fluid-filled cyst reveals a low, intermediate, or high signal intensity depending on the composition of the fluid. Proteinaceous fluid and subacute blood reveal high signal intensity on the Tl-weighted images, while the T2-weighted sequences disclose a bright signal. In benign, as well as malignant tumors, the Tl-weighted sequence most often reveals an intermediate signal intensity and intermediate to increased signal intensity on the T2-weighted image. Such differentiation may be useful in younger patients with certain types of cysts, such as a hemorrhagic bone cyst, where surgical intervention may not be indicated. Despite the application of the various radiological modalities, a definitive diagnosis often cannot be made and exploration and histologic examination is mandatory. Table 1 provides a list of the most common cysts, and benign and malignant tumors that are encountered in the mandible and maxilla. In order to arrive at a tentative radiologic diagnosis, various parameters should be analyzed. These radiologic criteria should be applied in each case and their analysis forms the basis for the final diagnosis. The following parameters are pertinent to the diagnostic evaluation: 1) location of the lesions within the mandible (symphysis, bod3; or ascending ramus) or maxilla; 2) relationship of the cyst to the adjacent tooth structures (whether the crown of the tooth is incorporated or whether the apex of the tooth is part of the cyst wall (radicular, dentigerous cysts); 3) shape of the lesions (round or oval) and the presence of interdigitation or finger-like projections between the tooth apices (hemorrhagic bone cyst); 4) degree of lucency manifested by the cystic cavity and the presence of calcification or bone (periapical fibrous dysplasia); 5) demarcation of the lesion (sharply delimited or less well defined); 6) sclerotic reaction or new bone formation (osteogenic sarcoma) and 7) presence of teeth or tooth derivatives within a lesion (odontoma). Cystic lesions of the mandible are defined as epithelial-lined cavities containing fluid or semisolid material. A microscopic examination of the lining, along with the radiographic findings, is necessary for the diagnosis. The odontogenic cysts arise from tooth derivatives and are differentiated on the basis of the composition of the epithelial layer, relationship to a tooth, and possible containment of calcifications. The radicular cyst is the most common cyst in the mandible and maxilla. It is a well circumscribed radiolucency arising from the apex of a tooth and is bounded by a thin rim of cortical bone. The dentigerous cyst incorporates the crown of a tooth, is variable in size, sharply delimited, and may expand bone, if of sufficient size. The keratocyst is lined by epithelial cells with keratinization of the cyst lining and may be multiloculated and demonstrate an aggressive growth pattern. If the cyst is incompletely removed, recurrence has been demonstrated in 20-60°70 of these lesions. Multiple keratocysts are found in the basal cell nevus syndrome, along with multiple basal cell nevi that eventually transform into basal cell carcinomas. In addition, there are skeletal abnormalities and ectopic excessive dural calcifications. There are a large variety of nonodontogenic cysts, such as the nasopalatine duct cyst, globulomaxillary cyst, and nasolabial cyst, which are differentiated on the basis of their loca-

Table 1. Cystic Lesions, Benign and Malignant Tumors of the Mandible and Maxilla

1. Odontogenic Cysts A) B) C) D)

Dentigerous Cyst Radicular Cyst Odontogenic Keratocyst Basal Cell Nevus Syndrome

I1. Nonodontogenic Cysts A) Fissural Cysts 1) nasopalatine duct cyst (incisive canal cyst) 2) globulomaxillary cyst 3) nasolabial cyst/nasoalveolar cyst B) Solitary, Simple, or Hemorrhagic Bone Cyst

111. Benign Odontogenic Tumors A) Epithelial Odontogenic Tumors 1) ameloblastoma B) Mixed Tissue Tumors of Odontogenic Origin 1) odontoma a) complex composite odontoma b) compound composite odontoma

IV Benign Tumors A) Fibrous Dysplasia B) Ossifying Fibroma C) Giant Cell Reparative Granuloma

E Malignant Tumors A) Carcinoma 1) secondary invasion B) Metastases 1) bronchogenic carcinoma 2) breast 3) hypernephroma C) Sarcoma 1) osteogenic sarcoma

tion. The nasopalatine cyst is located in the incisive canal, while the globulomaxillary cyst is located in the maxilla between the lateral incisor and the canine tooth. The nasolabial cyst occurs in soft tissues of the lateral aspect of the nose and adjacent upper lip. These cysts are characterized by their well defined contour and their slow expansion within the mandible or maxilla. The hemorrhagic bone cyst is, likewise, categorized as a nonodontogenic cyst and occurs predominantly in the mandible in young persons. It is usually unilocular and filled with clear or sanguinous fluid. The most common benign, but aggressive, tumor is represented by the ameloblastoma, which may be unilocular and multilocular. The aggressive growth pattern is manifested by ' bony expansion, loss of bone, and extension into the adjacent soft tissue structures, nasal or sinus cavities. On CT and MRI, there are cystic and solid components with their specific attenuation values or signal characteristics. There is a large, diverse group of benign tumors, including fibrous dysplasia, ossifying fibroma, and odontoma. They cause bony expansion and contain osteoid, calcified cartilage and tooth derivatives. They may involve the mandible or maxilla and, if large, extend into the adjacent structures.

S 30 Another benign lesion is the giant cell granuloma, which occurs in younger people and may be unilocular and multilocular, and cause marked bony expansion with considerable loss of bone. Removal may entail aggressive surgery, such as a hemimandibulectomy, in some instances. Malignant tumors represent a diverse group of lesions, which predominantly consist of carcinomas and sarcomas. The most frequent cancer involving the mandible is carcinoma of the floor of the mouth or gingiva with secondary bony invasion. Sarcomas are rare in the mandible and maxilla, and often occur in younger people. One of the most frequent sarcomas is

the osteogenic sarcoma, which contains calcification and new bone formation. Metastatic tumor is not infrequent in the mandible, but is often part o f a general malignant disease and may not be the predominant symptomatic area. CT and MRI are the modalities of choice in the assessment of malignant lesions of the mandible and maxilla. They are both complimentary, in that CT is better suited for bone analysis and demonstration of calcification, while MRI is slightty more specific in tissue characterization and also optimally demonstrates the boundaries of extra-osseous involvement.

Imaging the Parapharyngeal Space R.B. Lufkin UCLA School of Medicine, Los Angeles, California, USA Knowledge of the contents of the parapharyngeal space is essential in determining the differential diagnosis of masses in this region. The parapharyngeal space is lateral to the pharyngobasilar fascia which surrounds the nasopharynx. This region can be further subdivided into prestyloid and poststyloid compartments separated by fascia containing the tensor veli palatini muscle fibers (see Fig. 1). The medial pterygoid muscle and fascia form the lateral border of the prestyloid compartment and separate it from the masticator space. Based on these anatomic divisions, the poststyloid space contains the carotid artery, jugular vein, and the lower four cranial nerves. The prestyloid

Fig. 1. a Coronal. 1 - Medial Ptyergoid (MP) Fascia; 2 - Tensor Veli Palatini Fascia; FO - Foramen Ovale; LP - Lateral Pterygoid; PBF Pharyngobasilar Fascia; Long Arrow Pharyngeal Recess. (Figures adapted from reference 1). b Axial. ST= Stylomandibular Tunnel. A portion of the parotid gland passes here to enter the prestyloid space -

:~ ° ~ ':,;

F0

space is predominantly fat with a small amount of salivary gland tissue. Poststyloid lesions are generally related to the great vessels or cranial nerves (neural sheath tumors and paragangliomas) or lymph nodes. Salivary gland tumors are the predominant masses found in the prestyloid compartment. The most common salivary tumor in the prestyloid space are benign mixed tumors of accessory salivary tissue. These masses are generally wellcircumscribed lesions that push the internal carotid artery and jugular vein posterolaterally. Other salivary gland neoplasms include Warthin's tumor, mucoepidermoid carcinoma, adenoid cystic carcinoma, adenocarcinoma, and carcinoma arising in mixed cell tumor. On CT, they tend to be slightly more dense than muscle. Tl-weighted images on MRI are of intermediate signal intensity. MRI is particularly useful in delineating extension of the tumor into fat, muscle or nerve tissue, which may affect the clinician's treatment plans. For example, it is important to ascertain whether the deep parotid

$31 gland is affected as this may alter the surgical approach. (A deep lobe parotid lesion requires a trans-parotid surgical approach to control the facial nerve.) The presence of a well-circumscribed lesion without disruption of the soft tissue planes can be quite misleading as a malignant neoplasm may have this appearance. While MRI is excellent for delineating tumor extension, it is not particularly helpful in determining the histology. The pathologic diagnosis is most accurately obtained by fine needle aspiration. Surgical excision is the main treatment for salivary gland tumors. Although these tumors are seldom cured by radiation therapy, they are frequently reduced. Radiation plays a role in providing palliation for unresected lesions and symptomatic metastases. For malignant salivary tumors, the overall survival

rate (5 years) is approximately 80%. The survival is higher for mixed and mucoepidermoid neoplasms than for adenocystic carcinomas (72.7%). References

Curtin H (1987) Separation of the Masticator Space from the Parapharyngeal Space. Radiology 163:195-204 Mafee MF et at. (1988) Head and neck: high field magnetic resonance imaging versus computed tomography. Otolaryngologic Clinics of North America 21(3):513-46 Mancuso AA, Hanafee WN (1985) Computed Tomography and Magnetic Resonance Imaging of the Head and Neck, 2nd ed Unger J (1987) Head and Neck Imaging. New York: Churchill Livingstone, New York

Salivary Glands B.L. Carter Tufts University School of Medicine, Boston, Massachusetts, USA Salivary g l a n d s

Tumors -

The major and minor salivary glands have been studied for many years by varied approaches. Evolving imaging modalities have shifted in the respected roles played in the evaluation of these structures. The normal anatomy and variations of normal have been well documented first with sialography, then with nuclear medicine, CT, ultrasound, and MRI. Interventional techniques are now being applied to further the diagnostic capabilities of these various imaging modalities.

Pleomorphic adenoma or mixed tumor is the most commonly encountered salivary gland tumor, particularly in the parotid gland. Whereas 80% of parotid tumors are benign, 50% of submandibular tumors are malignant, and 90% of the very rare sublingual tumors are malignant. Roughly 40°/o o f minor salivary gland tumors are benign pleomorphic adenomas. Mass lesions in the salivary gland region are most readily identified with MR, but are often studied with contrast-enhanced CT or ultrasound depending upon availability of equipment. These imaging modalities will differentiate between masses extrinsic to or within the gland, solid versus cystic lesions, and invasive versus well encapsulated sharply defined lesions. Although the final diagnosis requires percutaneous or excisional biopsy, the differential diagnosis is aided by an assessment of various characteristics i.e. solid versus cystic, invasive (malignant) versus encapsulated (probably but not always be-

Technique

Plain film studies are still used for identification of radiopaque calculi. Sialography is indicated for the identification of ductal stenosis and/or ectasia, radiolucent calculi, penetrating trauma, salivary fistula, and for the identification of a siatocele. However, sialography is contraindicated in the presence of acute inflammatory disease. Radionuclide scanning using Technetium 99 m pertechnetate is used very little compared to previous years but it does help assess function of the salivary glands and is picked up in the majority of Warthin's tumors. CT scanning is widely used with a bolus injection of intravenous contrast material with 3 - 4 mm thick slices, contiguous from the external auditory canal to the lower border of the parotid and/or submandibular glands. These scans are done primarily in the axial plane with occasional additional coronal planes. CT with contrast enhancement is used for the evaluation of masses adjacent to and/or within the salivary glands, in the study of patients with inflammatory diseases in the area and for confirmation of calcification. M R l i s now preferred in many institutions for an evaluation of salivary gland masses. 3 - 4 mm slices in the axial plane with TI weighted images followed by T2 weighted images are the commonly accepted techniques. Coronal planes are occasionally used. Gadolinium DTPA has not been found to be particularly helpful in most instances. Ultrasound is helpful for differentiating between solid versus cystic tumors, for differentiating extrinsic from intrinsic masses within the glands, for the identification of proximity of masses to and/or involvement of adjacent vessels and for ultrasound directed biopsies.

benign and malignant

Table I. Salivary gland lesions - benign

Adenoma Pleomorphic adenoma (mixed tumor) Adenolymphoma (Papillary cystadenoma lymphomatosum) (Warthin's tumor) Monomorphic adenoma Sebaceous lymphadenoma Benign lymphoepithelial lesion: (Sjogren's syndrome) Myoepithelioma Oncocytoma Tumor-like condition: sialometaplasia Vascular tumors - Hemangiomas (capillary and cavernous) - Lymphangioma Lipoma Neurogenic tumors - Schwannoma - Neurofibroma

S 32 nign) solitary versus multiple nodules, bilateral versus unilateral involvement, and associated lymphadenopathy. Tables I and II list the more common types of benign and malignant tumors of salivary gland origin. The identification of tumor recurrence after surgery requires assiduous imaging techniques. Single or multiple nodules I mm or smaller in diameter occur within the operative site following excision of mixed tumors. The proximity of these recurrent nodules to the facial nerve poses a challenging problem to the surgeon. Obstruction

Intermittent swelling is indicative of obstruction due to a calculus (sialolith, stone) of the ductal system. This occurs most often within Wharton's duct where 80°7o to 90070 of the calculi occur, most of which are calcified. These calculi are usually large and opaque enough to be seen on plain occlusal films but small (1 mm) ones may require CT scan or sialography for identification. Multiple calculi are occasionally present. Calcifications within the parotid gland are unusual but do occur and are easiest to identify on the CT scan. Strictures of Wharton's or Stensen's duct due to recurring stones, trauma, poorly fitting dentures, etc., require sialography for identification. The numerous 1 8 - 2 0 ducts draining the sublingual glands to the floor of the mouth may occasionally join to form an accessory duct (Bartholins) draining into Wharton's duct. A n obstructed sublingual duct results in the development of a ranula, a cyst in the floor of the mouth. Extravasation of fluid from the obstructed sublingual gland extending below the mylohyoid muscle to the submental area results in a plunging ranula, a cystic structure anterior to the submandibular gland. Granulomatous

and

systemic

diseases

Bilateral diffuse enlargement of the parotid glands (Tables III, IV) occurs with sarcoidosis, diabetes, alcoholism, toxic effect of heavy metals, and some antibiotics such as sulfonamides. Multiple nodules within the parotid may occur with granulomas (cat scratch fever, tuberculosis, etc.), lymphoma and AIDS related adenopathy. Ultrasound differentiates solid from cystic masses. Sialography shows the typical appearance of autoimmune disease with focal punctate or globular collections of contrast material throughout the glands. The early changes affect the peripheral ducts whereas later stages of the disease cause distortion of the central ducts. The more advanced disease is detectable by a contrast-enhanced CT scan and by MRI.

Infections

Acute infections causing enlargement of the entire gland are diagnosed clinically and treated appropriately whether they be of bacterial or viral origin. The identification of an abscess may require a contrast enhanced CT scan, MRI, or an ultrasound study. Percutaneous needle aspiration and drainage can then expedite patient management. Chronic infection secondary to calculi, strictures and various disease states cause reduction in salivary flow. Sialodochitis may then develop which is best delineated by sialography with aqueous contrast material. See Tables IV and V.

Table

lI. Salivary gland tumors - malignant

Acinic cell carcinoma Adenocarcinoma Adenoid cystic carcinoma L~-aphoma Metastatic tumors Squamous cell carcinoma (skin) Basal cell carcinoma (skin) Melanoma - Lymphoma Miscellaneous tumors Mixed tumor - Biphasic malignant tumor Carcinoma arising in pleomorphic adenoma Mucoepidermoid carcinoma Oncocytic carcinoma Squamous cell carcinoma Table

III. Diffuse enlargement

Inflammatory Mumps Acute suppurative sialadenitis - Chronic recurrent non-obstructive sialadenitis Sialectasis Pneumoparotitis Toxic or drug induced Nutritional deficiency Metabolic disorders - Alcoholic cirrhosis Obesity Hormonal dysfunction Diabetes - Hypothyroidism - Gonadal (atrophy or dysfunction) Others - Sjogren's syndrome - Sarcoidosis Uremia Kussmaul's disease (fibromucinous plugs)

Table

IV. Inflammatory masses

Focal sialadenitis, cellulitis Abscess Chronic autoimmune sialadenitis Ganulomatous disease, adenopathy - Tuberculosis Sarcoidosis - Cat-scratch fever - Actinomycosis Lymphoepithelial cysts (HIV+)

Table

V. Cysts

Branchial cleft cyst Post inflammatory cyst Lymphoepithelial cysts (HIV+) Ranula (sublingual gland) Old hematoma

Miscellaneous

Postoperative and postradiation changes alter the appearance of the parotid gland. A persistent diffuse enhancement following intravenous contrast injection is often seen throughout the

parotid and submandibular glands following radiotherapy to the area. Surgical resection of the superficial portion of the parotid gland, interruption of the tympanic plexus or interrup-

$33 tion of the 9th cranial nerve may result in atrophy of the remaining portion of the parotid gland. Atrophic changes have also been reported after chronic obstruction to the duct due to surger3; trauma, and/or calculus. Atrophy of the salivary gland is to be distinguished from congenital absence which is very rare but has been reported. Pneumoparotitis, air within the ductal system of the parotid gland is a rare cause of diffuse enlargement. This has been reported as an occasional occupation hazard in musicians, glass blowers, balloon blowers, and as a self-induced phenomenon in adolescents with psychosocial problems. This may or may not be associated with inflammatory changes of the gland and may or may not require treatment with antibiotics.

References Batsakis JG (1979) Tumors of the head and neck. Clinical and Pathological Considerations. Williams and Wilkins, Baltimore, pp 1- 120

Byrne MN, Spector JG, Garvin CF, Gado MH (1989) Preoperative assessment of parotid masses: A comparative evaluation of radiologic techniques to histopathologic diagnosis. Laryngoscope 99:284-292 Cummings CW, Fredrickson JM, Harker LA et al. (1986) Otolaryngolog), Head and Neck Surgery. Volume II, Salivary Glands, Oral Cavity/Oropharynx. CV Mosby Co, St Louis, pp 961-1088 Curtin HD (1988) Assessment of salivary gland pathology. Otolaryng Clin North Am 21:547-573 Markowitz-Spence L, Brodsky L, Seidell G, Stanievich F (1987) Self-induced pneumoparotitis in an adolescent. Report of a case and review of the literature. Inter J Pediatr Otorhinolaryngol 14:i 13-121 Som PM, Bergeron RT (199t) Heat and Neck Imaging. Mosby Year Book, St Louis, pp 277-348 Tabor EK, Curtin HD (1989) MR of the salivary glands. Radiol Clin North Am 27:379-392 Tunkel DE, Loury MC, Fox CH, Goins MA, Jons ME (1989) Bilateral parotid enlargement in HIV seropositive patients. Laryngoscope 99:590- 595 Whyte AM, Hayward M (1989) Agenesis of the salivary glands: a report of two cases. Br J Radiol 62:1023-1026

Laryngeal Anatomy J.A. Castelijns Free University Hospital, Amsterdam, Netherlands The larynx extends from the base of the tongue to the trachea. It projects ventrally between the great vessels of the neck. The skeletal framework of the larynx is formed out of cartilages, which are connected by ligaments and membranes and moved by a number of muscles. The laryngeal skeleton consist of the hyoid bone, the thyroid, cricoid, the epiglottic and the paired arytenoid cartilages. There are three intralaryngeal compartments: the paired lateral paragIottic spaces and the midline preepiglottic space. To become familiar with the anatomy of MR images of the larynx, it is helpful to use the laryngeal cartilages as landmarks at various axial levels. The cartilages have a unique appearance at each level within the larynx, providing a rapid orientation of any given laryngeal CT or MRI section.

Laryngeal skeleton The hyoid bone denotes the superior extent of the larynx except for the free-standing epiglottis. This bone is already ossified in infancy and is found on MR images with the typical appearance of bone: a high signal marrow, surrounded by a low signal cortical rim. The hyoid bone has three basic parts: the body and the two greater horns. A zone of low signal intensity, representing a fibrous connection is present between the body and the two greater horns. The cricoid cartilage, thyroid cartilage, and the greater part of the arytenoid cartilage consist of hyaline cartilage and are subject to ossification like all hyaline structures. This tends to be a endochondral type of ossification with a true medullary cavity surrounded by a cortical rim. The changes in hyaline cartilage are the subject of long discussions in the literature. In some studies it is maintained that the processes of ossification and calcification are interrelated, whereas other authors favour the view that these processes are totally independent of each other. Changes in the cartilages as visualized by CT, may be defined with the term "calcification", and changes in hyaline carti-

lages observed in MR images, may correspondingly be defined "ossification". Non-ossified and ossified cartilages are seen with clear contrast. Non-ossified cartilage is demonstrated with an intermediate signal intensity on Tl-weighted images. Ossified cartilage has a typical three-layered appearance: high signal bone marrow being surrounded by low signal cortical rims. Cortical bone is imaged by MRI with low signal intensity due to the lack of mobile protons. Bone marrow is always seen with high signal intensity, irrespective of the proportion of fatty and hemopoietic content. In fact, hemopoietic marrow consists of 25070-50% fat. Comparison of CT and MR images, with corresponding microscopic sections suggests that the patterns of calcification and ossification are similar to a certain degree. The degree and extent of the thyroid cartilage ossification varies. Generally- it is more ossified in males and with increasing age. Ossification appears to occur mainly in the early twenties and is modified only slightly in the ensuing years. The degree of ossification is greatest in the caudal and dorsal portions. The inner and outer surfaces do not ossify in a corresponding pattern; the left and right laminae of the thyroid cartilage do not ossify symmetrically. Focal areas of ossification are common. The epiglottic cartilage and the vocal processes of the arytenoids consist of elastic fibrocartilage; this type of cartilage mostly does not ossify.

Laryngeal compartments Important for the growth and spread of laryngeal cancers are the midline preepiglottic space (PES) and the paired lateral paraglottic spaces (PGS). On MRI, the PES is of high signal intensity owing to its high fat content. The epiglottic cartilage is seen as an area of relatively low signal intensity just deep to the mucosa. A zone of decreased signal intensity is mostly visible in the upper part of this space just deep to the epiglottic carti-

S 34 lage. This area of lower signal intensity is produced by the hyoepiglottic ligament. The walls of the PES can be recognized on sagittal images: the thyrohyoid membrane (and more caudally the thyroid cartilage) as the ventral wall; the epiglottic cartilage as the posterior wall and the hyoepiglottic ligament as the superior wall. Laterally to the PES, both PGS are situated as shown on the frontal images. These spaces are bounded laterally by the thyroid and cricoid cartilages with the crico-thyroid ligament and medially by the ventricle, the false vocal cord and the quadrangular membrane. The cricoarytenoid and vocal muscles, lying within the conus elasticus, occupy the inferior portions of the PGS. The two lateral PGSs are filled with loose areolar tissue

and the PES is filled with more dense connective tissue, including collagen bundles between mucous glands. The PGS has a high intensity on MR images, the PES has a fairly high intensity. The false cord and the true vocal cord can be identified as two distinct structures, separated by the laryngeal ventricle. The moveable posterior attachments of the true vocal cords are the vocal processes of the arytenoid. The vocal cords meet each other at the immovable anterior commissure, which attaches to the inner perichondrium of the thyroid cartilage. On MRI, the vocal cords are normally seen in abducted position during quiet breathing and show intermediate signal intensity. The false vocal cords mainly contain adipose tissue and therefore show up bright.

Laryngeal Cancer and Staging of Cervical and Retropharyngeal Lymph Node Metastases A . A . Mancuso University of Florida, College of Medicine, Gainesville, Florida, USA

Choosing the appropriate imaging study Cancers of the larynx and hypopharynx are evaluated with a combination of CT and MRI. Conventional tomography and laryngography play little or no role in the evaluation of these malignancies unless more modern techniques are not available. Plain films really have no role except in planning of radiotherapy portals. CT is of proven value in the evaluation of cervical and retropharyngeal lymphadenopathy related to cancers in the upper aerodigestive tract. There is only very preliminary data suggesting MRI may be as accurate as CT for detecting nodal disease. CT can, in experienced hands, detect early capsular penetration and determine the extranodal extent of tumor. There is no MRI data comparing CT and MRI for the detection of early capsular penetration and extranodal spread. There is limited experience suggesting that CT, MRI and ultrasound might be necessary to evaluate the extent of tumors relative to the carotid artery in cases of advanced extranodal spread, suspicious for carotid fixation. The choice of CT or MRI as the primary imaging modality for cancer of the larynx and for the evaluation of cervical metastatic disease is highly dependent on the needs of referring head and neck surgeons and radiation oncologists at a particular institution. CT is less expensive than MRI, the study takes approximately 1 5 - 20 minutes to complete, and it is safe. MRI, using currently available techniques, will be significantly degraded by motion artifact in at least 20% of the patients studied for cancer of the larynx and hypopharynx; significant artifacts due to motion are rarely a problem on CT scans of less than 3 seconds duration when the patients suspend inspiration. MRI is more informative when used with paramagnetic contrast; however, this tends to diminish contrast between tumor and fat. For these reasons, the optimal MRI technique is probably one in which fat suppression techniques can be employed along with paramagnetic contrast enhancement and the scans are done rapidly. Such techniques are now in development but not widely available. These techniques may also be more difficult to imple-

ment at mid and low fields, which means that dispersion of these particular capabilities may be limited for some time to come. For the technical and socioeconomic reasons outlined in the previous paragraph, CT is preferred as the initial examination at the University of Florida for evaluating laryngeal and hypopharyngeal cancer. CT will answer all the questions necessary for patient care in well over 90% of patients with this disease and, in our opinion, is superior to MRI for staging cervical nodes. In our practice MRI studies are used in somewhere between 5% and 10%0 of these patients to answer specific questions that may alter the treatment plan. Those institutions without advanced MR capabilities, however, must be aware that with careful CT techniques and good interpretive skills CT can provide virtually all the information necessary for optimal treatment planning and follow-up in the vast majority of patients with cancers in this region.

Technical highlights Studies of the larynx should be done with contiguous, no thicker than 3 - 4 ram, sections. It is absolutely essential that the sections be angled parallel to the plane of the true vocal cords. Failure to do this will result in skewed images through the true cord level and these may lead to serious error in the evaluation of tumors relative to the true vocal cord, laryngeal ventricle and false cords as well as erroneous evaluation of the extent of subglottic disease. Intravenous contrast should always be used on CT examinations. Both CT and MRI examinations must include a detailed evaluation of the cervical nodes in all hypopharyngeal, supraglottic and advanced glottic and subglottic cancers. T2 glottic cancer does not require a complete study of the cervical nodes unless there is significant spread above the true cord level or extensive subglottic disease. Cervical nodes should, in general, be studied from approximately the C2 level to the thoracic inlet. Detailed scrutiny of the retropharyngeal nodes is necessary in advanced hypopharyngeal and supraglottic cancer or any cancer that has recurred. T1 cancer of the true vocal cords

$35 need not be studied with any imaging if the vocal cord mobility is normal. Any patient with reduced vocal cord mobility should be imaged prior to therapy. CT study of the larynx is usually done in suspended inspiration. No special maneuvers are required. In lesions involving the false cord, ventricle and true cord levels, an additional set of scans done in quiet respiration will often be obtained. Occasionally, 1 . 5 - 2 mm thick sections will be used to evaluate tumors of the true cord, ventricle false cord region if subtle spread to or across the ventricle will potentially alter the surgical approach to the patient (i. e., vertical hemilaryngectomy vs. total laryngectomy). Coronal MRI examination may also be used to detect subtle spread to the ventricle and false cord. Otherwise, multiplanar imaging is unnecessary. Supplemental MRI is occasionally used to detect early spread of tumor beyond the confines of the larynx or hypopharynx and, on rare occasions, to help confirm evidence of subtle cartilage invasion. MRI can be particularly helpful in pyriform sinus cancers to show spread beyond the apex to involve the esophageal verge or proximal cervical esophagus. This may be submucosal and an otherwise

undetectable disease which can alter the surgical management of these patients. Newer concepts and controversies This presentation will include a brief review of pertinent anatomy and technical issues discussed in the preceding section. Some newer concepts of spread patterns and relevance of imaging to clinical decision-making will then be presented, including: 1. The limits of our ability to detect cartilage invasion. 2. The fact that lesions with limited cartilage invasion and early exolaryngeal spread are frequently radiocurable. 3. Predictive value of tumor volume in selecting supraglottic cancers that are favorable vs. unfavorable for radiotherapy. 4. Use of MRI and CT to define the submucosal extent of hypopharyngeal carcinoma as an aid to planning pharyngeal reconstruction. 5. Superior laryngeal neurovascular bundle as a conduit for extralaryngeal spread. 6. Refined diagnostic concepts in evaluating cervical metastatic disease.

Neck Vessels - Anatomy and Pathology D.W. Chakeres Ohio State University College of Medicine, Columbus, Ohio, USA The main vascular structures of the neck that will be discussed are the carotid, vertebral, thyroid, and thyrocervical arteries; and the internal and external jugular veins. The gross, angiographic and cross-sectional anatomy of these vessels as they are seen by CT and MRI will be reviewed. The varying appearance of arterial and venous blood flow on MRI is dependent on the physiologic flow characteristics and the MRI technique selected. The differences between two-dimensional Fourier transform and three-dimensional Fourier transform MR angiogram techniques will be stressed. The advantages and disadvantages of CT, MRI, and angiography will also be reviewed. Congenital variations of the neck vessels may be particularly important in interventional radiographic procedures, where unanticipated interconnections of the external and internal circulation may exist. Neck trauma can be associated with multiple abnormalities, including: laceration, pseudoaneurysm, occlusion, dissection, and arteriovenous fistula. Infections of the neck can be associated with venous thrombosis. Less frequently, direct arterial and intimal changes can be seen with septic processes. Immunosuppressed patients are particularly sensitive to septic arterial thrombosis or pseudoaneurysm formation. One

of the most common lesions of the cervical arterial system is arteriosclerotic disease. A brief overview of new MR angiographic techniques will be discussed. Occasionally, benign vascular tumors such as hemangiomas are encountered in the neck. They have radiographic characteristics similar to those seen in the face, and can be treated similarly. Paragangliomas are also highly vascular tumors with characteristic locations. Most lesions arise either intraluminally within the jugular system or at the carotid bifurcation. Neurofibromas and schwannomas can also occur within the carotid sheath, but are usually less vascular than paragangliomas. Some thyroid and parathyroid tumors can be seen angiographically. Venous sampling can be important in localization of hormonally active thyroid and parathyroid tumors. Most malignant neck tumors, such as squamous cell carcinoma, are avascular; though venous invasion and thrombosis are more common. Induced vasculitis of the carotids can be seen following radiation therapy. Necrotic tumors can be associated with rupture and life threatening hemorrhage that can be treated in part endovascularly.

S 36

Postgraduate Course in Head and Neck Radiology Morning Session Chairman: G.D. Potter, New York, USA

09.00 am-09.45 am

CT and MRI of the Normal Temporal Bone F. Veillon, Strasbourg, France

09.45 a m - 10.15 am

Neurosensory Hearing Loss and Tinnitus G.E. Valvassori, Chicago, USA

10.15 a m - 10.45 am

Vascular Masses and Pulsatile Tinnitus W. W.M. Lo, Los Angeles, USA

10.45 a m - 11.15 am

Coffee Break

11.15 a m - 11.45 am

Inflammatory Disease of the Temporal Bone A. Chiesa, Brescia, Italy

11.45 a m - 12.15 pm

Congenital Ear Abnormalities P.D. Phelps, London, United Kingdom

12.15 p m - 0 1 . 0 0 pm

Temporomandibular Joint: Anatomy and Pathology Diagnostic Imaging P.-L. Westesson, Rochester, USA

0t.00 p m - 0 2 . 0 0 pm

Lunch

CT and MRI of the Normal Temporal Bone E Veillon, M. Bintner Department of Radiology I, H6pital Central, Strasbourg, France

Anatomy The temporal bone is composed of three parts: the tympanic bone, the squamous bone and the petrous bone. The tympanic bone has anterior, inferior and posterior walls that form the essential part of the external auditory canal. The squamous bone has a thin, vertical portion, and an horizontal portion divided into antero-, supra-, and retro-meatal parts. The last portion is formed by the vertical retro-meatal segment, completing the external auditory canal. The petrous bone has three surfaces: the anterior close to the temporal lobe, the posterior, close to the brainstem and cerebellum, and the inferior surface, an area of vascular and nervous canals and foramina. The temporal bone contains three cavities: the external, middle and inner ear.

The external auditory meatus is composed of the tympanic bone and the vertical retromeatal portion of the squamous bone. The tympanic cavity is formed by the tympanic, squamous and especially the petrous bone. It has six walls: anterior, posterior, external, internal, superior and inferior. The facial nerve canal is an important structure coursing along the medial wall and behind the posterior wall. The middle ear contains three ossicles: malleus, incus and stapes, whose vibrations are modulated by the tensor tympani and the stapedius muscles. These two muscles run through separate canals, one horizontal and the other vertical. The inner ear is made of an anterior and posterior labyrinthine portion, with the cochlea placed anteriorly and the vestibnlum and semi-circular canals oriented in the three spatial planes. The internal auditory meatus opens in the inner ear by different canals.

S 37 Technical aspects in the study of the temporal bone

Computed Tomography (CT) The main plane is horizontal, parallel to the orbito-meatal line or infraorbito-meatal line. The thickness of the sections is 1 or 1.5 ram. The increment is 0.5 or 1.0 mm. Some other planes can be useful: the frontal plane, necessary for the study of the tympanic cavity, especially the tegmen, the scutum and the floor. It is also very useful to delineate the inferior wall of the tympanic part of the facial canal. The sagittal plane is very interesting for the study of the middle ear, especially in post-operative cases. It is also useful for the evaluation of the vestibular aqueduct. An oblique plane is very helpful in the study of the stapes and incus. This section is tangential to the long process of the incus, and has a characteristic V-shaped appearance. Another oblique plane perpendicular to the axis of the petrous bone is useful for the evaluation of the vestibular aqueduct. A last oblique plane is used for the study of the turns of the cochlea. This section is tangential to the basal turn of the cochlea. A nearly equivalent plane is used for the study of the auditory tube and the internal carotid canal. All these planes can now be easily reformated, having a quality which is comparable to the direct equivalent cuts.

Magnetic Resonance Imaging (MRI) The horizontal sections with T 1- or T2-weighted sequences are especially useful for the inner ear and can be complementary to the CT scan. For the middle ear, the results of both methods cannot be compared. For example, CT allows satisfactory visualization of the chorda tympani canal and nerve in the tympanic cavity as well as the different ligaments and tendons adjacent to the ossicles. All these structures are not visible on MR. The injection of Gadolinium can be useful in the study of the facial nerve, especially for the geniculate ganglion and the junction between the tympanic and vertical portion. The thickness of the sections is between I and 3 ram. Reformated sections can also be obtained in the different spatial planes.

Results CT is the basic examination for depicting the anatomy of the temporal bone, MRI provides very little supplementary information on the cavities or canals of this region. The external auditory meatus is well studied in the horizontal and sagittal planes. The tympanic membrane is delineated in the three spatial planes, especially the frontal plane. The tympanic cavity is well analysed in the horizontal and frontal planes. A frontal section is necessary for the study of the scutum and tegmen. The ossicles and especially the stapes are correctly appreciated on horizontal sections, but for a very good result, an increment of 0.5 mm is necessary. The other planes are also very useful for the ossicles, especially the oblique one. The inner ear particularly the lateral semi-circular canal is nicely evaluated with horizontal sections. The coronal and sagittal sections give additional information. The canals situated in the bottom of the internal auditory meatus are well seen in the horizontal plane. The facial nerve canal is followed in the labyrinthic and tympanic portions, on consecutive horizontal sections. The geniculate ganglion has a variable diameter, and this constitutes a normal CT variant. The tympanic portion of the facial nerve canal is often open, especially above the vestibular window. The third portion is nicely delineated in the sagittal plane. A slightly oblique sagittal section shows the posterior part of the chorda tympani canal. Medially to the third portion of the facial canal, the three spatial planes demonstrate the canal of the stapedius muscle. Anteriorly to the third portion of the facial canal, a venous duct is visible in the tympano-squamosal fissure. The inferior tympanic nerve canal is visible on horizontal sections very close to the round window. A little notch is appreciated on the promontory, corresponding to the course of this nerve. A fair number of fissures are visible by CT. The most interesting is the superior petro-squamosal fissure, entirely delineated from the anterior to posterior part. This constitutes a weak area in trauma of temporal bone, where a shearing injury may involve this structure.

Neurosensory Hearing Loss and Tinnitus G.E. Valvassori University of Illinois, Chicago, Illinois, USA Neurosensory hearing loss may be caused by peripheral or labyrinthine lesions or by central or retrolabyrinthine pathology. At the present state of the arts CT of the temporal bone is the study of choice for peripheral lesions and MR for central pathology. The selection of patients for the proper imaging study is based on the result of the auditory and vestibular tests. Peripheral neurosensory losses They account for approximately 75% to 80% of all cases of neurosensory hearing toss.

The most common etiopathogenic factors are: 1. Congenital malformation of the labyrinth. It should be pointed out that in at least 80% of the patients with congenital neurosensory hearing loss, the imaging study is negative since the anomaly is limited to the membranous labyrinth. 2. Trauma. Total hearing loss is found in the majority of the patients with transverse fractures of the petrous pyramid. In longitudinal fractures, sensorineural hearing loss is not uncommon but in the greater majority of the cases is produced by labyrinthine concussion rather than extension of the fracture into the labyrinth.

$38 3. Labyrinthitis. This group can be divided into three subgroups as follows: a. Serous or toxic labyrinthitis, not uncommon in patients with meningitis or middle ear infections not eroding the labyrinthine wall. The imaging study is negative. b. Viral labyrinthitis, usually extending to the labyrinth via the cerebrospinal fluid or acoustic nerve. The MR study performed after injection of contrast often shows enhancement of the inner ear structures. c. Bacterial labyrinthitis. The infection spreads into the labyrinth either from the middle ear following erosion of the labyrinthine wall or through the cerebrospinal fluid usually following a meningitis. Erosion of the labyrinth and obliterative labyrinthitis are the most common imaging findings. 4. Ototoxicity usually produced by drugs such as streptomycin, gentamycin, quinine, aspirin and others. The imaging study is negative. 5. Tumors, arising within the temporal bone or extending to the temporal bone by direct extension or hematogenous spread, often erode or destroy the labyrinth.

6. Otodystrophies and bony dysplasias: most common in this group are otosclerosis and Paget's disease. Retrocochlear neurosensory loss

It accounts for 20% to 25% of all cases of pure sensorineural hearing loss. Approximately 50% of these patients have cerebellopontine angle tumors. Three groups of lesions are recognized: 1. Petrous apex lesions such as congenital cholesteatomas, cholesterol granulomas and occasionally glomus tumors, involving the 8th cranial nerve within the internal auditory canal. 2. Cerebellopontine angle lesions, mostly acoustic neuromas and meningiomas. Cross compression of the cochlear nerve by vascular loops in the cerebellopontine cistern or internal auditory canal can cause tinnitus and occasionally sensorineural hearing loss. 3. Central pathology involving the brain stem, cerebellum and central auditory pathways. The most common lesions in this group are multiple sclerosis, tumors, ischemia from vascular insufficiency or occlusive vascular disease, aneurysm and intraaxial hemorrhage.

Vascular Masses and Pulsatile Tinnitus W.W.M. Lo, M.D. University of Southern California, Department of Radiology, St. Vincent Medical Center, Los Angeles, California, USA Tinnitus may be from intrinsic (vestibulocochlear) or extrinsic causes (muscular or vascular). Intrinsic tinnitus is subjective and audible only to the patient. Extrinsic tinnitus is often objective and potentially audible also to the examiner. Muscular tinnitus such as myoclonus of the palatal muscles or the tensor tympani muscle can be pulsatile but is not usually pulse-synchronous. Vascular tinnitus, our subject of discussion, is always pulse-synchronous. Subjective tinnitus is a common complaint. Some receive radiologic evaluation when tumor, anomaly, or trauma are suspected. Most, however, are from Meniere's disease or syndrome, viropathies, drugs, allergy, noise, or systemic diseases and do not come to the attention of the radiologist. Often the cause is unclear and effective treatment lacking. Objective tinnitus is far rarer but, by contrast, can usually be traced to a specific cause; and in the case of vascular tinnitus the cause is often significant, but treatable. Furthermore, in vascular tinnitus the radiologist tends to have a more active role in the diagnosis and sometimes also the treatment. The cases for vascular tinnitus may be arterial, arteriovenous, or venous (Table). In our experience, paraganglioma and idiopathic tinnitus are by far the most common, but others have cited dural arteriovenous fistula. Arterial causes

The arterial causes include the aberrant arteries and the stenofic arteries. The aberrant arteries are rare but extremely important because of the hazards of mistreatment which they invite when mistaken for tumors.

The aberrant carotid artery may be initially seen in any age group. Some of the patients have pulsatile tinnitus, some have conductive hearing loss, but most have relatively mild or no

Table. Vascular Tinnitus: Causes and Radiologic Investigation Arterial

Fibromuscular dysplasia Atherosclerosis Styloid carotid compression Petrous carotid aneurysm Aberrant carotid artery Laterally displaced carotid Persistent stapedial artery

CT CT CT CT CT

MRA MRA MRA MRI

A A A A

MRI MRI

A A

MRI MRI

A A A

Arteriovenous

Paraganglioma (tympanicum) (jugulare) Other vascular tumors Paget's disease of bone Cerebral AV malformation Dural AV fistula Vertebral AV fistula

CT CT CT CT

Venous

Chronic anemia Pregnancy Thyrotoxicosis Intracranial hypertension Large or exposed jugular bulb Idiopathic venous tinnitus

MRI MRV MRV

$39 symptoms and do not require treatment. The aberrant carotid artery clinically simulates a paraganglioma in the middle ear and has often been diagnosed after myringotomy or biopsy, with disastrous consequences such as massive hemorrhage and hemiplegia. The aberrant artery enters the tympanic cavity through an enlarged inferior tympanic canaliculus and then undulates through the middle ear to enter the horizontal carotid canal through a dehiscence in the carotid plate. The ipsilateral ascending carotid canal is absent. CT is diagnostic. Unless an associated aneurysm is suspected, angiography is not necessary. The rarer laterally displaced carotid artery presents the same hazards. The persistent stapedial artery courses from the infracochlear carotid through the stapedial obturator foramen and then enlarges the tympanic facial nerve canal en route to the middle fossa to become the middle meningeal artery. It must not be mistaken for a facial nerve tumor. The ipsilateral foramen spinosum is absent. CT is also diagnostic. Among the stenotic arteries, fibromuscular dysplasia (FMD) is probably the most important. About one third of the patients with carotid FMDs have pulsatile tinnitus as a presenting symptom. In some this may be their primary symptom. Besides surgery and antiplatelet therapy, FMD has been treated successfully with transluminal angioplasty. Superimposed spontaneous carotid dissection may also precipitate pulsatile tinnitus. Atherosclerosis of the internal carotid, compression of a tortuous carotid by an elongated styloid process, and petrous carotid aneurysm have also been reported as causes of pulsatile tinnitus. Arteriovenous causes

These include the high-flow tumors and the high-flow shunts. Paraganglioma is the second most common tumor of the temporal bone and the most common tumor in the middle ear. Whether involving the jugular bulb or skull base (glomus jugulare) or confined to the middle ear or mastoid (glomus tympanicum), the majority of the paragangliomas first appear with pulsatile tinnitus. CT with bone detail can be used to differentiate the tympanicum tumors, which require no angiography and only simple surgery, from the jugular tumors, which require angiography, preoperative embolization, and extensive surgery. MRI may also be helpful. Other vascular malformations in the head and neck outside the temporal bone may also be causes. Paget's disease of bone frequently contains extensive arteriovenous shunting. In one series of 165 patients with skull involvement, 31 had tinnitus, 20 of whom had pulsatile tinnitus. Cerebral AV malformations may rarely cause symptomatic bruit and in at least one case, pulsatile tinnitus was the primary complaint. Dural sinus AV fistulas are in most, if not all cases, acquired consequent to the recanalization of a thrombosed sinus. The transverse, sigmoid, and cavernous sinuses are the most common sites. Nearly all patients with lateral or sigmoid AV fistulas have pulsatile tinnitus and an audible bruit. While the small lesions occasionally close spontaneously, the large ones may cause cerebral ischemic or hemorrhagic events or chronic increased intracranial pressure. A variety of treatment methods have been employed successfully. In one series, self-administered external compression benefited about half of the patients without complications. Patients who gained no relief from external compression can be treated by embolization with either isobutyl cyanoacrylate or polyvinal alcohol sponges. The most

problematic cases can be treated by a combination of embolization and surgery. In a series of 28 patients treated with these various methods, there were three strokes but no deaths. Surgical excision with packing of the sinus also give excellent results to most of the patients, but in a series of 27 patients there were 2 deaths by exsanguination. Vertebral AV fistulas are most often caused by stab and bullet wounds. Iatrogenic causes include direct vertebral puncture for angiography and anterior cervical dissectomy. Spontaneous development occasionally occurs in patients with neurofibromatosis 1. Endovascular occlusion is now the treatment of choice. Venous causes

When noise created by turbulent flow in the jugular vein exceeds the masking capability of the ear, it becomes venous tinnitus to the patient. Venous tinnitus when audible to the examiner is usually- heard around the ear and invariable on the side of the dominant jugular vein. It is abolished by light pressure on the ipsilateral jugular vein. Venous tinnitus may be heard in conditions of hyperdynamic systemic circulation such as chronic anemia, pregnancy, and thyrotoxicosis. Occasionally pulsatile tinnitus can be a prominent symptom of intracranial hypertension from a variety of causes. In rare cases of idiopathic intracranial hypertension, it can be the presenting symptom or even the only symptom. After exclusion of all specific causes, some causes of venous tinnitus remain unexplained and hence "idiopathic". They may or may not be associated with large, high or exposed jugular bulb. They are usually in women who are otherwise healthy. Most of the patients require only explanation and reassurance. The symptoms often resolve spontaneously. When truely intolerable, the tinnitus can be abolished by jugular ligation under local anesthesia. In the absence of a contralateral vein, jugular ligation may cause intracranial hypertension; in the presence of dehiscence o f the jugular plate, jugular ligation may cause herniation of the bulb into the middle ear. In such rare cases a sigmoid-jugular bypass may be applied, with or without jugular iigation. When a high bulb is exposed by a dehiscence of the jugular plate and becomes visible as a bluish retrotympanic mass, it may be mistaken as a tumor. Radioiogic investigation

A detailed algorithm for investigation of vascular tinnitus is complex, but simple triaging can be helpful. (1)A tinnitus abolished by light pressure on the ipsilateral neck is presumably venous and does not require arteriography. MRI and, if necessary, MR venogram will suffice. (2) A tinnitus associated with a pulsatile middle ear mass can often be evaluated with high-resolution CT alone. MRI and angiography are needed only when deep tumor is found. (3) If there are signs of a shunt, angiography is generally unavoidable. MRI may be used to evaluate the brain. (4) If a systolic murmur is present in the neck, M R A may temporize and angiography may be done if still necessary. (5) If no specific signs are found, high-resolution CT should be done and angiography, if still necessary. Reference

Lo WWM (1991) Vascular tinnitus. In: Sore PM, Bergeron RT (eds) Head and neck imaging, 2nd ed, p 1108 (72 references)

S 40

Inflammatory Disease of the Temporal Bone A. Chiesa Department of Radiology, University of Brescia, Italy Inflammatory lesions are the most common disease of the middle ear. The radiological investigation of these lesions is done by CT in all cases. A clinically suspected or an already diagnosed chronic otitis does not necessarily require a CT examination. In the majority of cases, the presence of a perforation in the tympanic drum permits a direct and easy otoscopic investigation. The cases in which a CT examination is mandatory are restricted to those patients where: - the external auditory canal is filled by polyps or other material, thus excluding a correct diagnostic otoscopy; the tympanic membrane is not interrupted, thus avoiding the direct visualization of the middle ear;

- the ear has been already operated. In the first two conditions, the radiological investigation should differentiate chronic otitis with no cholesteatomatous lesions from cholesteatomatous chronic otitis. Usually the differential diagnosis is possible, but in some cases the presence of a cholesteatoma is only demonstrated at surgers: In the latter condition, the CT examination should demonstrate: - what kind of surgical operation was done (different tympanoplasties, etc.); what is the situation of residual structures; - recurrencies, which are possible in many operated cavities.

Congenital Ear Abnormalities P.D. Phelps Department of Radiology, Royal National Throat, Nose and Ear Hospital, London, UK Congenital ear abnormalities have many and varied types and present a wide range of clinical problems, the commonest of which is deafness. A defect producing deafness may in any one individual involve any or all of the parts of the hearing mechanism, namely the external, middle, or inner ears or the central neural connections and may be unilateral or bilateral. A family history of deafness, a history of maternal Rubella during pregnancy, neonatal asphyxia or jaundice, or the identification in the neonatal period of a deafness-associated abnormality, e.g. external ear deformities, or Treacher Collins syndrome, may alert the clinician to the possibility of deafness, but more commonly the hearing loss is only identified as a result of a hearing screening programme. The essential management of such cases lies in the fields of audiology and special education, but this management may be influenced or modified as a result of the assessment by imaging. Currently the greatest value of imaging lies in an assessment of the bony structures in and around the ear, but indirect information about the possible state of cochlear function or the position of the facial nerve is available. Against this background it is possible to consider when and why imaging of congenital ear abnormalities is appropriate. Probably any child with a severe hearing loss should have an imaging assessment of the temporal bone though the number of demonstrable structural abnormalities will be small. The chief aims of imaging are: a. To assess the bony configuration of the labyrinth and thereby help to predict cochlear function. If the abnormality present is incompatible with any cochlear function, then it immediately removes from the plan of management the use of sound amplification or surgery in the involved ear. Some inner ear abnormalities are associated with progressive hearing loss. b. To assess the anatomy of the middle ear and ossicles, particularly for surgical exploration and reconstruction, even if the

only surgical treatment is to be in the form of a bone anchored pinna or hearing aid. c. To assess the position and configuration of surgical hazardous structures, e.g. facial nerve, carotid artery, jugular bulb and dura mater. d. To identify abnormalities associated with the risk of cerebrospinal fluid fistula. Unfortunately most cases are referred for imaging between the ages of two and five, when sedation is usually necessary. The ideal is to identify candidates for imaging during the first few weeks of life, when the examination can often be accomplished without anaesthetic. Inner

ear

deformities

The traditional classification of these anomalies into Michel, Mondini and not much else, is quite inadequate and should be abandoned. The majority of structural deformities of the labyrinth have a resemblance to the normal stages of foetal development and therefore seem to indicate arrest of normal maturation. Even in the severest deformities at least some vestige of an otocyst can almost always be identified, but it is arrest at the next stage of development, when the labyrinth has begun to form, which is the most important. A severe dysplasia is associated with a very real risk of a spontaneous CSF fistula, or meningitis. The Mondini deformity in which the cochlea has a normal basal turn and distal sac, may have some cochlear function. A dilated vestibular aqueduct may occur in isolation or with some other inner ear anomalies such as a Mondini deformity. It is associated with a progressive and often fluctuant sensorineural hearing loss. Deficient bone between the lateral end of the internal auditory meatus and the basal turn of cochlea occurs in one variety of X-linked deafness associated with a stapes gusher and has only recently been recognised.

$41 Middle ear deformities

The main feature to be assessed is the configuration of the middle ear space and whether or not it is air containing. In the majority of cases of unilateral atresia of the external meatus, the mastoid is well pneumatised and the middle ear cavity of relatively normal shape. At the other extreme, the mastoid cellularity may be minimal or absent and the middle ear reduced to a slit-like cleft. If the middle ear cavity is air containing its outline and contents are relatively easy to assess, but it may be filled with undifferentiated mesenchyma. Ossicular abnormalities vary considerably in degree, from a minor deformity in the stapes superstructure, to the very rare complete absence of ossicles. The bodies of the malleus and incus are commonly fused to some degree. The position of the facial nerve is of great importance to the surgeon operating on a congenitally abnormal ear. The course of the second and third parts of the nerve is dependent upon the normal development of the branchial arches. If the atresia is due only to maldevelopment of the tympanic ring, then the second and third parts of the nerve follow a relatively normal course, but in more severe anomalies the nerve tends towards a more direct route from the genicutar ganglion to the soft tissues of the face. Exposure of the nerve in the middle ear cavity due to underdevelopment of the bony canal is the most common finding at surgery and the often associated overhang of the nerve over the oval window and full positioning of the second and third part of the nerve, as frequently occurs in the Treacher Collins syndrome, limits surgical access to the oval window.

Imaging will also show a short vertical segment of a nerve and a high stylomastoid foramen, a situation when the nerve can be expected to turn forwards into the parotid gland at a higher more superficial level than normal.

Syndromes with ear abnormalities

Congenital means existing at birth, but it is virtually impossible to differentiate between deafness which is congenital and that which is of rapid onset in the neonatal period. Imaging has an important role for identifying and distinguishing between structural abnormalities of the labyrinth, as occur in KlippeilFeil syndrome and anomalies like the dilated vestibular aqueduct, or bone dysplasias, like osteogenesis imperfecta and the sclerosing bone dysplasias where deafness is progressive. Perhaps the best known of all syndromes with structural deformities of the hearing organ and face are the so-called "first arch" syndromes, hemifaciai microsomia/oculo-anricular vertebral dysplasia/ Goldenhar's syndrome. The ear lesions are usually bizarre and severe. The pinna is often represented by a small tag. Meatal atresia and middle ear abnormalities are almost constant findings and there may be gross depression of the tegmen. The ear abnormalities in the Treacher Collins syndrome (mandibulo-facial dysostosis) are bilateral symmetrical and characteristic, although they vary in severity. The mastoid is un-pneumatised and the attic and antrum are often reduced to slit-like proportions. Atresia of the external meatus is a less constant feature, although ossicular abnormalities are common.

Temporomandibular Joint: Anatomy and Pathology,

Diagnostic Imaging

P.-L. Westesson University of Rochester School of Medicine and Dentistry, Rochester, New York and Eastman Dental Center, Rochester, New York, USA

Background

Imaging of the temporomandibular joint (TMJ) has been available for many years. The initial techniques were transcranial and skull films with special emphasis on the TMJ area. During the last ten years, there has been a substantial improvement in the imaging techniques with introduction of arthrography and more recently MRI. These imaging techniques have provided new information that has improved our understanding of TMJ pathology and patho-physiology. Clinical, radiographic and surgical observations in combination have helped in defining the symptoms and natural course of internal derangements specifically related to disc displacement. MRI is the newest modality for imaging of the TMJ, and emphasis on this modality will be given in this lecture. Normal anatomy of the TMJ

The TMJ consists inferiorly of the mandibular condyle and superiorly of the glenoid fossa and articular tubercle of the temporal bone. The articular surfaces are covered by a dense collagenous fibrous tissue instead of hyalin cartilage as seen in most other joints of the body. The TMJ disc divides the joint into

two separate compartments that do not normally communicate. The joint is surrounded by a capsule that runs like a funnel from the periphery of the articulating surface on the temporal bone downwards attaching around the neck of the condyle. The capsule is composed of collagenous tissue with a thickening in the lateral capsule constituting the TMJ ligament. The upper and lower heads of the lateral pterygoid muscle merge into the capsule anteriorly and medially. Joint function

In a normal joint, there is both rotation and translation of the condyle during opening. There is more translation in the upper space and more of rotation in the lower space. The area posterior to the condyle is filled by expansion of the posterior disc attachment with mouth opening. The parotid gland also fills the space behind the condyle at mouth opening. Internal derangement and related pathology

Internal derangement is the general term that implies the mechanical failure that interferes with the smooth action of the joint. The most common cause of internal derangement in the

S 42 TMJ relates to disc displacement. This is actually so common that the term "internal derangement" has been used interchangeably with disc displacement. Disc displacement may occur in any direction, but the most common displacement occurs anteriorly. With improved imaging methods, we are also able to demonstrate lateral and medial displacements.

Etiology of internal derangement A single etiology for internal derangement has not been established. The following four theories have been suggested: 1) trauma, 2) microtrauma from occlusal interferences, 3) hyperactivity of the upper head of the lateral pterygoid muscle, and 4) frictional alterations in the joint.

Disc displacement In the clinical spectrum of TMJ internal derangement, the earliest form of disc displacement is the displacement with reduction. In this condition, the disc is anteriorly displaced when the jaw is closed, but reduces usually with a clicking sound to normal position with jaw opening. Disc displacement with reduction usually precedes the next stage, which is disc displacement without reduction. This condition was initially termed "closed lock" (Wilkes 1978a, b). This term was later replaced by the term "disc displacement without reduction" (Katzberg et al. 1980) because some patients are able to open relatively well despite the disc being anteriorly displaced. This is due to deformation of the disc and elongation of the posterior disc attachment. When the disc is functioning in its abnormal position, it will be deformed. Characteristically, the disc deformation starts in the posterior disc part with the thickening of the posterior band. If nothing is done, the disc continues to deform and eventually develops into a biconvex disc. Perforation is a late stage sign of disease. Perforations are not usually located in the disc proper in the typical internal derangement patient (Westesson et al. 1985), but instead in the posterior disc attachment.

Accuracy of clinical examination Several studies have attempted to determine the intra-articular status based on findings by clinical examination alone (Roberts et al. 1985, 1986, 1987a, b, c). The overall accuracy rate for the clinical examination was only between 60% - 7 0 % . From the results of these studies, it is obvious that there is a need for further examination to accurately determine the status of the joint, and the first step after clinical examination should be directed towards imaging.

Plain film imaging In the past, the most common way to image TMJ was with plain film in a transcranial projection. This will show the lateral aspect of the condyle and temporal component. Because of the angulation of the X-ray beam from above, there wilt be no clear demonstration of the central and medial parts of the joint. Neither will there be any information about any soft tissue components of the joint, which are more closely related to patient symptoms than osseous changes. For these reasons, the next step in imaging should be directed towards soft tissue depiction.

Arthrography Arthrography of the TMJ was described more than forty-five years ago. The technique was initially developed in Denmark by the Danish professor Fleming Norgaard (Norgaard 1944, 1947).

There were only a few clinicians that adapted the technique after Norgaard, and the few" that did (Campbell 1965; Tollen 1974), found the technique difficult to use and of only limited value to the clinician. Therefore, the technique of arthrography of the TMJ almost died out for about thirty years until it regained popularity at the end of the 1970's, mainly in the United States and Scandinavia. There are at least five factors that can be attributed to the renewed interest in TMJ arthrography. These are 1) recognition that disc displacement is a common cause of TMJ symptoms, 2) new treatment modalities that require accurate information about status of soft tissues of the joint, 3) radiographic image intensifier facilitated injection of contrast media, 4) modern radiographic contrast medium made the examination less painful for the patient, and 5) an increased awareness of clinicians and patients that intra-articular disorders could account for TMJ symptoms. The main factor is, of course, the identification of disc displacement and internal derangement as a common source of symptoms. Arthrography can be performed with injection of contrast medium into the lower, upper, or into both joint spaces. The most popular technique is probably injection into the lower joint space followed by fluoroscopy in a transcranial projection (Farrar and McCarty 1979). The main indication for arthrography is to assess position and function of the disc in patients who, on clinical examination, presented with symptoms suggestive of an internal derangement. There are only a few contra-indications. The main contra-indication is an infection in the pre-auricular area.

Arthrographic findings In the normal TMJ, the anterior recess of the lower joint space is relatively small, although variations may occur (Westesson et al. 1990). The most common abnormalities seen in the TMJ are different types of disc displacement and degenerative joint disease. The arthrographic sign of this displacement is enlargement of the anterior recess of the lower joint space. Deformation of the disc is a sequela of the displacement and abnormal function. There are a few complications of arthrography. The most frequent one is slight discomfort for one or two days after the examination. It has been our experience that the complications can be kept at a minimum with a well trained examiner. It is common to encounter more post-procedural pain with an inexperienced arthrographer.

MRI MRI is the most advanced technique for imaging of the TMJ. There are no known biologic side effects of MRI. A suggested scanning protocol for high-field MR sequences is shown in Table 1. An extremely important aspect to optimal TMJ diagnosis by MRI is to have good surface coil technology. Specialized small surface coils have been developed for the TMJ that provide outstanding anatomic detail in the area of the joint. Multiplanar MR scanning in the sagittal and coronal plane is vital since both anterior, medial and lateral displacement can be detected. In the normal joint, the posterior aspect of the disc is located on top of the condyle with the jaw closed. On opening, the condyle moves downward under the disc and the disc moves forward with the condyle under the articular eminence. In the coronal plane, the disc is crescent shaped and is superior to the condyle. The most common findings in MRI of the TMJ are different types of anatomic disc displacement. Disc displacement is fur-

S 43

Table 1. Scanning parameters for MR imaging using bilateral surface coils Image

Scanning Time

1. Axial localizer TR = 300 TE = 16 NEX = 0.5 FOV = 18 Thickness = 3 mm Matrix = 256× 128

25 sec

2. Sagittal, dosed TR = 2000 TE = 20 and 80 NEX = 0.5 FOV = 10 cm Thickness = 3 mm Matrix = 256x 192

3 rain 17 sec

3. Sagittal, open TR = 1000 TE = 20 NEX= 1 FOV = 13 cm Thickness = 3 mm Matrix = 256 × 192

2 min 9 sec

4. Coronal, closed TR = 2000 TE = 20 NEX = 1 FOV = 10 cm Thickness = 3 mm Matrix = 256× 192

3 rain 52 sec

If a splint is provided by the clinician, additional sagittal scans are performed with the splint in place. Total scanning time for a complete bilateral TMJ examination is about 12 min. Table time is approximately 30-40 rain.

ther divided into displacement with and without reduction. M R I also provides information about medial and lateral displacement of the disc. Deformation of the disc can also be clearly demonstrated with MRI. A series of recent reports (Schellhas et al. 1989; Schellhas and Wilkes 1989) have suggested that M R I may provide an insight into the biology of the bone marrow o f the condyle. It is clear from our experience with imaging normal asymptomatic volunteers that this decreased signal does not occur in normal volunteers, and when it is seen in patients it is usually associated with extensive pathology. The M R images resemble what has been described in avascular necrosis of the hip. It is, however, not clear from the histologic point of view that this actually represents avascular necrosis of the mandibular condyle and further investigations are needed to understand avascular necrosis o f the mandibular condyle and its association with disc derangement,

Imaging algorithms 1. The initial imaging of the patient with T M J pain and dysfunction is usually the plain film or panoramic radiograph. 2. The most important objective for patients with symptoms o f T M J disorders should be soft tissue studies. C T is inferior to M R I in the depiction o f disc and C T should therefore be replaced by MRI. Multiplanar imaging is valuable in demonstrating medial and lateral displacement of the disc, the ab-

sence of radiation and the ease o f imaging are all factors that should direct the decision towards M R imaging. For postsurgical or post-treatment imaging, M R I is probably also the imaging modality o f choice. 3. Arthrography should be the first choice if the dynamics of the joint dysfunction is of primary concern. Another reason for selecting arthrography would be if the presence or absence o f the perforation is essential for the evaluation of the patient. Arthrography can be used to establish a mandibular position for protrusive splint therapy. 4. Arthrography is the alternative technique if M R I is not available. 5. C T for soft tissue should be considered only when M R I and arthrography are not available or when the osseous components o f the joint are of primary concern.

References Campbell W (1965) Clinical radiological investigations of the mandibular joints. Br J Radiol 38:401-421 Farrar WB, McCarty WL Jr (1979) Inferior joint space arthrography and characteristics of condylar paths in internal derangements of the TMJ. J Prosthet Dent 41:548-555 Katzberg RW, Dolwick MF, Bales DJ, Helms CA (1980) Arthrotomography of the temporomandibular joint. AJR 134:995-1003 Norgaard F (1944) Artrografi af kaebeleddet. Preliminary report. Acta Radiol 25:679- 685 Norgaard F (1947) Temporomandibular arthrography. Thesis, Munksgaard, Copenhagen Roberts CA, Tallents RH, Espeland MA, Handelman SL, Katzberg RW (1985) Mandibular range of motion versus arthrographic diagnosis of the temporomandibular joint. Oral Surg Oral Med Oral Pathol 60:244 - 251 Roberts CA, Tallents RH, Katzberg RW, Sauchez-Woodworth RE, Manzione JV, Espeland MA, Handelman SL (1986) Clinical and arthrographic evaluation of the temporomandibular joint. Oral Surg Oral Med Oral Pathol 62:373-376 Roberts CA, Tallents RH, Katzberg RW, Sanchez-Woodworth RE, Espeland MA, Handelman SL (1987) Comparison of arthrographic findings of the temporomandibular joint with palpation of the muscles of mastication. Oral Surg Oral Med Oral Patho164:275 -277 (a) Roberts CA, Tallents RH, Katzberg RW, Sanchez-Woodworth RE, Espeland MA, Handelman SL (1987) Comparison of internal derangements of the TMJ with occlusal findings. Oral Surg Oral Med Oral Pathol 63:645-650 (b) Roberts CA, Tallents RH, Katzberg RW, Sanchez-Woodworth RE, Espeland MA, Handelman SL (1987) Clinical and arthrographic evaluation of the location of temporomandibular joint pain. Oral Surg Oral Med Oral Pathol 64:6-8 (c) Schellhas KP, Wilkes CH (1989) Temporomandibular joint inflammation: Comparison of MR fast scanning with Tt- and T2-weighted imaging techniques. AJNR 10:589-594 Schellhas KP, Wilkes CH, Baker CC (1989) Facial pain, headache, and temporomandibular joint inflammation. Headache 29:228-231 Toiler PA (1974) Opaque arthrography of the temporomandibular joint. Int J Oral Surg 3:17-28 Westesson P-L, Bronstein SL, Liedberg J (1985) Internal derangement of the temporomandibular joint: Morphologic description with correlation to joint function. Oral Surg Oral Med Oral Pathol 59:323-331 Westesson P-L, Eriksson L, Kurita K (1990) Temporomandibular joint: Variation of normal arthrographic anatomy. Oral Surg Oral Med Oral Pathol 69:514-519 Wilkes CH (1978) Structural and fnnctional alterations of the temporomandibular joint. Northwest Dent 57:287-294 Wilkes CH (1978) Arthrography of the temporomandibular joint in patients with the TMJ pain-dysfunction syndrome. Minn Med 61:645 - 652

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Postgraduate Course in Head and Neck Radiology Afternoon Session Chairman: M. Takahashi, Kumamoto, Japan 02.00 pm-02.45 pm

Ocular Imaging M. E Mafee, Chicago, USA

02.45 pro-03.30 pm

Orbital and Visual Pathway Imaging R.A. Zimmerman, Philadelphia, USA

03.30 p m - 04.00 pm

Coffee Break

04.00 pm-04.30 pm

Neck Masses M. Lenz, Munich, Germany

04.30 pm-05.00 pm

Lower Neck and Upper Mediastinum D.L. Reede, New York, USA

05.05 p m - 06.00 pm

Business Meeting ESHNR

Ocular Imaging M.F. Mafee University of Illinois at Chicago, Illinois, USA Nuclear magnetic resonance (NMR) has served as an important tool in analytic chemistry for the past four decades. The development of magnetic resonance imaging (MRI) technology in 1973 by Paul Lauterbur, PhD, provided a major breakthrough in diagnostic medical imaging. The anatomic detail demonstrated by an MR proton image is a representation of three physical properties of static tissue: proton (spin) density and TI and T2 relaxation times. The eye is an ideal organ to be evaluated by MRI. The eye consists of three primary layers: (1) the sclera, the outer layer, composed primarily of collagen-elastic tissue; (2) the uvea or middle layer, a richly vascular and pigmented tissue consisting of the choroid, ciliary body and iris; and (3) the retina or inner layer, the neurosensory stratum of the eye. The vitreous, which acts as a biologic shock absorber, represents about two-thirds of the volume of the eye or approximately 4 ml. Vitreous humor is a gel-like transparent extracellular matrix, interspersed with 0.2% hyaturonic acid polymers, 9 8 % - 99% water, and small amounts of soluble protein. Posterior hyaloid, retinal and choroiflal detachment

Accumulation of fluid within the three potential spaces of the globe can result in detachment of various coats.

Posterior hyaloM detachment The posterior hyaloid space is a potential space between the posterior hyaloid membrane and sensory retina. Posterior hyaloid detachment usually occurs in adults over the age of 50 years. It is usually caused by liquefaction of the vitreous and is associated with macular degeneration. Posterior hyaloid detachment may also occur in children with persistent hyperplastic primary vitreous (PHPV). The posterior hy~tloid membrane is thin and is invisible on MRI or CT. It becomes visible when blood or other fluid fills the posterior hyaloid space, causing the membrane to be visibly thickened. Differentiation of fluid in the retrohyaloid space from that of fluid in the subretinal space may not be possible by either CT or MRI scans.

Retinal detachment Retinal detachment results from separation of the sensory retina from the retinal pigment epithelium (RPE) with accumulation of fluid in the potential subretinal space. Ultrasonography is superior to MRI and CT in the evaluation of retinal detachments since often CT and occasionally MRI may not show the detached retina. On axial CT or MRI scans the detached retina

$45 may appear as a homogeneous increased density or intensity of the globe. Since the retina is very thin, it cannot be directly visualized on CT or MRI scans. However, it may be shown when it is outlined by significant contrast differences between the subrefinal effusion and the vitreous cavity. The CT and MRI appearance of retinal detachment varies with the amount of subretinal exudate and with the degree of organization of the subretinal material.

sensitivity in detecting calcification. Lesions less than 3 mm in thickness are not recognized by MR technology to date. Larger tumors appear slightly or moderately hyperintense in relation to normal vitreous on T I W and PW MR images. On T2W MR images the tumors appear as areas of markedly to moderately low signal intensity. Even extensive calcification noted on CT scans may be missed in all MRI pulse sequences. Retinoblastomas enhance following IV injection of Gadolinium-DTPA contrast.

Choroidal detachment Choroidal detachment results from the accumulation of fluid (serous choroidal detachment) or blood (hemorrhagic choroidat detachment) within the potential space between the choroid and the sclera. Ocular hypotony is the essential underlying cause of serous choroidal detachment. Ocular hypotony increases the permeability of the choroidal capillaries, leading to the transudation of fluid from the choroidal vasculature into the uveal tissue. This transudation causes a diffuse swelling of the entire choroid (choroidal effusion). As edema of the choroid increases, fluid accumulates in the potential suprachoroidal space resulting in serous or exudative choroidal detachment. ChoroidaI effusion usually has a crescentic or ring-shaped appearance on both CT and MR scans. Serous choroidal detachment appears as semilunar or ring-shaped area of variable attenuation or intensity on CT or MRI scans. Acute hemorrhagic choroidal detachment appears as a high intensity mass on computed tomography which can be quite large and irregular. MRI is an excellent technique in the evaluation of patients with choroidal detachment, particularly when ultrasound or CT in conjunction with the clinical examination have not provided sufficient information. Differentiation of retinal detachment and choroidal detachment is not always possible since distinction between suprachoroidal and subretinal effusion may be difficult.

Malignant uveal melanoma Malignant melanoma is the most common tumor to involve the uvea. Malignant uveal melanomas are unusual in blacks; the white:black ratio being about 15:1. Metastatic tumors, choroidal detachment, choroidal nevi, choroidal hemangioma, choroidal cysts, neurofibroma and schwannoma of the uvea, leiomyoma, adenoma, medulloepithelioma, retinal detachment, choroidal detachment and disciform degeneration of the macula are some of the benign and malignant lesions that may be confused with malignant uveal melanoma. Uveal melanomas can usually be accurately diagnosed by ophthalmoscopy, fluorescein angiography or ultrasonography. The MR characteristics of melanotic lesions are thought to be related to the paramagnetic properties of melanin. Uveal melanomas appear as areas of moderately high signal (greater signal intensity than vitreous) on T1 and proton weighted MR studies. On T2 weighted images, melanomas appear as areas of moderately low signal (lesser intensity than vitreous). These MR characteristics are similar to those of retinoblastoma. Retinal detachment, associated with choroidal melanoma, is better shown by MR than by CT scans. Gadolinium-enhanced MRI is valuable in the evaluation of choroidal melanomas. They show moderate enhancement. Gadolinium contrast increases the sensitivity of MRI for detecting melanoma, and for detecting extrascleral extension.

Retinoblastoma Retinoblastoma, the most common intraocular tumor of childhood, is a highly malignant retinal rumor. The tumor arises from neuroectodermal cells (nuclear layer of the retina) destined to become retinal photoreceptors. Leukokoria (a white, pink white or yellow white pupillary reflex) is the most common presenting sign of retinoblastoma. Other causes of leukokoria include persistent hyperplastic primary vitreous (PHPV), retinopathy of prematurity, Coats disease, posterior cataract, coloboma of the choroid or optic disc, uveitis, larval granulomatosis and other rare conditions. MRI is not as specific as CT scanning in the diagnosis of retinoblastoma due to its lack of

Choroidal and retinal hemangioma Choroidal hemangiomas are usually seen in association with Sturge=Weber disease (encephalotrigeminal syndrome), while retinal hemangiomas (angiomatous retinae) occur in patients with yon Hippel-Lindau disease. On CT, choroidal hemangiomas appear as an ill-defined mass, which enhances markedly following contrast infusion. On MRI, choroidal hemangiomas may appear hypointense or slightly hyperintense on T1 weighted images and hyperintense on T2 weighted images. CT and MRI may demonstrate intense contrast enhancement that are almost characteristic for hemangioma.

Orbital and Visual Pathway Imaging R.A. Zimmerman The Children's Hospital of Philadelphia, Pennsylvania, USA

Purpose:

Methods:

To examine the current role of medical imaging in the evaluation of patients with visual field abnormalities a n d diseases of the orbit and visual pathways.

CT: Conventional CT has now been augmented with spiral thin section CT (1 - 2 mm thick slices). This visualizes detailed orbital anatomy and gives a data base for reformating bony and soft tissue 3D images.

S 46 MRL" Conventional spin echo MRI is now augmented by gradient echo and spin echo thin section fat suppressed gadolinium enhanced studies. MR angiography and angiotomography demonstrates vascular anatomy and pathologic processes (e.g., aneurysm) of the circle of Willis and its branches. D

i

s

c

u

s

s

i

o

n

The neuro-ophthalmologic visual field examination provides specific anatomic localization of a lesion within the visual pathway. The medical imager must utilize his knowledge of this anatomy and his technical capabilities in order to provide the diagnostic imaging study that answers the clinical problem.

Table Intraorbital Disease Processes affecting the Optic Nerve - Glioma Meningioma -

Intracranial Disease Processes affecting the Optic Nerve, Chiasm and Tract - Visual Pathway TUmors Meningiomas Pituitary Adenomas Craniopharyngiomas - Aneurysms Inflammatory Diseases Demyelinating Sarcoid -

-

-

-

Intracranial Disease Processes affecting the Geniculate Nuclei, Optic Radiations and Visual Cortex - Infarction Demyelinating Diseases Neoplasms -

-

Neck Masses M. Lenz Department of Diagnostic Radiology, Technical University of Munich, Klinikum rechts der Isar, Munich, Germany Modern tomographic techniques (US, CT, MRI) play an increasing role in the pretherapeutic evaluation and posttherapeutic monitoring of neck masses. They offer information on the location and size of a lesion and reliably depict its expansion and infiltration into surrounding structures. Thus these techniques significantly supplement the clinical and endoscopic evaluation which often assess only superficially located structures. Additionally, criteria such as signal intensity (before and after the application of contrast media), and structure (inhomogeneity, borders, calcifications) offer important differential diagnostic clues on the character and the dignity of a lesion. High resolution real-time ultrasound (US) (with 5 and 7.5 MHz probes) is the easiest method in terms of technical requirements and patient exposure. US offers high sensitivity in the detection of lymph node metastases and reliably differentiates solid from cystic lesions. Its disadvantages are a) the unsurmountable bone and air barrier that precludes the assessment of important regions of the neck, and b) the fact, that topographic relationships are less easily demonstrated to clinicians with US than with CT or MRI. Furthermore, the accuracy of US depends in a high degree on the experience of the ultrasonographer. High resolution contrast enhanced computed tomography (CT) ( 4 - 5 mm slice thickness, 1 - 4 sec scan time, 512 x 512 display matrix, 150 ml contrast medium with 300-370 mg Iodine/ml) also offers very high sensitivity and specificity in lymph node evaluation. Analysis of density before and after contrast application, if necessary with dynamic sequential contrast enhanced CT, allows the differentiation of various masses

(lymph node metastasis, malignant lymphoma, cyst, lipoma, glomus tumor etc.). Modern high resolution CT scanners offer a complete examination of the entire region (base of skull to jugulum) in less than 10 min. The depiction of primary lesions is also included in the same examination. Magnetic resonance imaging (MRI) without and with Gadolinium-DTPA is the technique that excels in tissue contrast. Coronal and sagittal planes can be imaged without a change of patient position. Beam hardening artifacts by dense bone or dental fillings do not exist. The method of choice are T1 weighted spin echo sequences before and after administration of Gadolinium-DTPA and especially T1 weighted gradient echo sequences after Gadolinium-DTPA, that offer superior sensitivity especially in the evaluation of lymph nodes. Proton density and T2 weighted sequences are not useful due to their long measurement times and resulting motion artifacts. Examination times, even with modern techniques, are considerably longer (40 min and more) than CT studies, especially since various images from differently weighted studies have to be analyzed for a complete evaluation. In conclusion, contrast enhanced CT in combination with clinical evaluation has to be regarded as the method of choice for assessment of lesions in the neck. This holds especially true for N-staging but also for the assessment of lesions with unknown dignity. Time-consuming and expensive MRI should be used only for special questions. Ultrasound is especially suited for short term monitoring, e.g. during chemotherapy of malignant lymphomas.

S 47

The Lower Neck and Upper Mediastinum D.L. Reede The Long Island College Hospital, Brooklyn, New York, USA Lower neck

The radiographic evaluation of the lower neck and thoracic inlet can be accomplished by using either CT or MR. Interpretation of these studies requires that one be familiar with the basic anatomy and the common pathologic entities that occur in this area. The thoracic inlet is the junctional area between the neck and the chest. It parallels the first rib; thus it tilts downward anteriorly. Several important neurovascular structures are encountered in this area, and the relationships among these structures are easy to remember if the anterior scalene muscle is used as a reference point. Two major vessels are found here, the subclavian artery and the subclavian vein. The subclavian vein and phrenic nerve are located anterior to the anterior scalene muscle. The subclavian artery and brachial plexus are situated posterior to the anterior scalene muscle. The vagus nerve and phrenic nerve cross the thoracic inlet anterior to the subclavian artery and posterior to the brachiocephalic vein, with the vagus nerve located medially and the phrenic nerve laterally. The vagus nerve is located within the carotid sheath. On the right side it gives off the recurrent laryngeal nerve at the level of the right subclavian artery at the cervicothoracic junction. This nerve loops around the subclavian artery and travels superiorly in the tracheo-esophageal sulcus enroute to the larynx. On the left side, the recurrent laryngeal nerve arises from the vagus nerve much lower (at the level of the aortic arch). The vagus nerve then passes between the aorta and the left pulmonary artery (aorto-pulmonic window), travelling posteriorly to the tracheo-esophageal sulcus, to then follow the same course up to the larynx as its counterpart on the right. The left recurrent laryngeal nerve is much longer than the right, subsequently it is more vulnerable to damage from mediastinal pathology. The phrenic nerve originates primarily from the C-4 nerve root but also receives minor contribution from C-3 and C-5. In the neck this nerve travels beneath the fascia which envelops the anterior scalene muscle and travels vertically downward across the muscle from a lateral to a medial position. Inferiorly in the neck it passes medial to the muscle and then crosses the anterior border of the subclavian artery. The phrenic nerve travels through the thorax along the extreme lateral margin of the mediastinum. It is in contact with the mediastinal pleura literally throughout its entire course to the diaphragms.

The brachial plexus is formed by the C-4 through T-1 nerve roots. There are several components of the brachial plexus (roots, trunks, division and peripheral nerves). These various components have a constant relationship with structures that can be readily identified either on CT or MR. The roots of the brachial plexus are located between the anterior and middle scalene muscles. The divisions and cords are found behind the subclavian artery in the lower neck and at the level of the thoracic inlet. Unlike the other components, the peripheral nerve encircles the axillary artery. Vocal cord paralysis - Pediatric etiologies

In the pediatric age group, congenital anomalies are the primary cause of vocal cord paralysis. These infants usually have multiple congenital defects. Anomalies of the central nervous system such as hydrocephalus, meningocele, and myelomeningocele are frequently associated with an Arnold-Chiari malformation. Thus as the medulla and cerebellum protrude through the foramen magnum, the 10th cranial nerve is stretched which leads to the development of a vocal cord paralysis. Vocal cord paralysis -

Adult etiologies

1. Trauma 2. Infection: bacterial and viral pneumonia, meningitis, poliomyelitis 3. Neurologic disorders: multiple sclerosis, myasthenia gravis 4. Cardiovascular: cardiomegaly, aortic aneurysm, mitral stenosis 5. Tumors: lung, bronchi, esophagus, thyroid Brachial plexopathy -

Etiologies

1. Trauma 2. Neoplasm (metastatic disease is more common than primary neoplasm) 3. Radiation injury uncommon with less than 6000 rads. Phrenic nerve palsy -

Etiologies

1. Trauma 2. Neoplasm (either primary tumor of the nerve or secondary to involvement from other tumor) 3. Infection.

S 48

Scientific Sessions

Scientific Session: Head and Neck Imaging Techniques Moderators: D.W. Chakeres, Columbus, USA and U. Salvolini, Ancona, Italy 08.30 a m - 0 8 . 4 5 am

Keynote address: MRI Techniques of the Temporal Bone D.W. Chakeres, Columbus, USA

08.45 a m - 10.30 am

Scientific Papers 1 - 11

10.30 a m - 11.00 am

Coffee Break

08.45am-10.30 am Scientific Papers 1-11 001

Dynamic MR imaging of head and neck tumors M. Takahashi, T. Sawada, Y. Sakamoto, R. Nishimura, H. Uozumi, M. Sumi, Kumamoto, Japan

002 MRI of head and neck tumours with 2D turbo-flash sequences P. Held, A. Atzinger, P. Lukas, K. Pf'andner, R. Bienert, K. Kress, H. Kett, W.-D. Gassel, N. Rupp, S. Braitinger, Passau/Munich, Germany 003 3-D MR imaging of tumours of the head and neck P. Held, C. Prtill, H. Kett, N. Rupp, Passau, Germany 004 Planning and simulation of cranio-maxillofacial surgery using 3-dimensional reconstructions R. Kikinis, D.E. Altobelli, H.E. Cline, W.E. Lorensen, J. Mulliken, E A. Jolesz, Boston/Schenectady, USA 005 Partial RF echo planar imaging: initial clinical experience in the head and neck G.H. Zoarski, K. Farahani, P.S. Melki, E A. Jolesz, R.V. Mulkern, B.A. Jabour, R.B. Lufkin, Los Angeles/ Boston, USA 006 Clinical evaluation of MR angiography in the head and neck region Th.J. Vogl, J.O. BaJzer, M. Juergens, H. Schedel, J. Lissner, Munich, Germany

007 CT and MRI in relationship with functional neck dissection. A radiological study of topographic anatomy M. De Nicola, U. Salvolini, V¢ Masala, G. Teatini, Ancona/Sassari, Italy 008 Imaging of paranasal sinuses - selection of optimal technique C.S. Zee, T. Becker, S. Destian, J. Ahmadi, H.D. Segalt, Los Angeles, USA 009 Diagnosis of lesions in the neck: Value of GD-DTPA enhanced MR imaging M.A. Mikhael, E.M. White, Evanston, USA 010 High resolution MR imaging of the vestibulocochlear nerve M.A. Brogan, P. Schmalbrock, Columbus, USA 011

Turboflash MRI of the internal auditory canals M. Shah, J.S. Ross, Cleveland, USA

$49

Keynote address

1

MRI T E C H N I Q U E S OF THE T E M P O R A L B O N E Donald W. C h a k e r e s M.D. O h i o S t a t e U n i v e r s i t y C o l l e g e of M e d i c i n e

Takahashi M, Sawada T, Sakamoto Y, Nishimura R, Uozumi

MRI has b e c o m e the s t a n d a r d imaging m o d a l i t y of choic:e fer e v a l u a t i o n o'f soft tissue a b n o r m a l i t i e s of the temporal bone. MRI has many a d v a n t a g e s over CT, the m o s t i m p o r t a n t are it's e x c e l l e n t t i s s u e c h a r a c t e r i z a t i o n and a n a t o m i c detail. C o n t r a s t e n h a n c e m e n t ol ~ m e n i n g e a l and otic c a p s u l e s t r u c t u r e s can be seen. Blood flow w i t h i n the c a r o t i d and j u g u l a r s y s t e m s can be a s s e s s e d a c c u r a t e l y and noninvasively. H e m o r r h a g e in c e r t a i n s t a g e s can be best e v a l u a t e d with MRI. B e c a u s e of this, MRI is i n d i c a t e d for e v a l u a t i o n of soft t i s s u e tumors (acoustic neuroma)~ giant aneuysms. v e n o u s o c c l u s i v e disease~ t o r t u o u s or a n o m o l o u s v e s s e l s (ectopic carotid) ~ l a b r i n t h i t i s (Ramsey Hunt s y n d r o m e ) , n e u r i t i s (Bell's palsy)~ i n f e c t i o n ( m a l i g n a n t e x t e r n a l otitis), and c o n g e n i t a l a n o m o l i e s (preop c o c h l e a r i m p l a n t evaluation). S t a n d a r d n o n c o n t r a s t e n h a n c e d TI and T2 w e i g h t e d two d i m e n s i o n a l F o u r i e r t r a n s f o r m (2DFT) spin echo i m a g i n g t e c h n i q u e s are impertant~ p a r t i c u l a r l y in e v a l u a t i o n of the brain. Three dimensional Fourier transform (3DFT) g r a d i e n t echo imaging t e c h n i q u e s are now a v a i l a b l e ~ i t h e x t r e m e l y high r e s o l u t i ~ n ~ exceedir, g that of CT. 3DFT i m a g e s (:an also be acquired that can be post p r o c e s s e d into a n g i o g r a p h i c displays, s u b s t i t u t i n g for- s t a n d a r d a n g i o g r a p h i c exams.

DYNAMIC MR IMAGING OF HEAD AND NECK TUMORS H, Sumi M Department of Radiology, Kumamoto University School of Medicine Thirty patients with various head and neck tumors were evaluated with conventional spin echo techniques, dynamic MR imaging and postcontrast Tt-weighted images. Dynamic MR imaging was performed with spin echo technique (TR/TE 200/15 msec, acquisition time 25.6 seconds), following rapid injection of Gd-DTPA 0.1 mmol/kg body weight. Six to 8 serial images were obtained every 30 seconds for 3 to 4 minutes. Contrast material enhancement ratio of the tumor showed rapid rise with slower or no decline over 4~5 minutes, whereas the signal to noise ratio was most prominent at 30 to 60 seconds after injection of contrast media with rapid decrease. Dynamic MR imaging was more useful in deliniation of the margin of the tumors and evaluation of the internal architecture than postcontrast T1- and T2-weighted images. Gd-DTPA dynamic MR imaging was particularly useful in deliniation of carcinoma of the tongue and carcinoma of the oropharynx. Dynamic MR imaging should be added when deliniation of the tumor was not sufficient with conventional spin echo technique.

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3

Y~I OF HEAD A N ~ N E C K ~IINOURS WITH 2DTURBO-FLASH SEQUENCES

3D ~

P.Held, A.Atzinger, P.Lukas*, K.Pf~indner, R.Bienert, K.Kress, H.Kett, W.-D.Gassel, N.Rupp, S.Braitinger KlinikumPassau (FRG) *Klinikum rechts der Isar, M~inchen (FRG)

P.Held, C.Priill, H.Kett, N.Rupp KlinikL~n Passau ( FRG )

The purpose of this study was to estimate the value of 2D turbo-FLASH (TFL) intensity-vs-time-studies (Gad-DTPA) for the following purposes: tumour delineation; differential diagnosis of Schwannomas, meningiomas, hemangiomas and paragangliomas; imaging of the hypopharynx and larynx with Valsalva's maneuvres and phonation studies; monitoring of therapy of head and neck cancer; followup of paragangliomas after radiotherapy (2D TFL versus F~A). Technique: 2D TFL TR 6,5 TE 3 TI 500 ms, flip angle 8 ° 30 measurements, delay between the measure~mnts=Isec, I acquisition, Gad-DTPA: injection velocity 10m] Magnevist / 5sec, dosage: 0,1 ml Magnevist /kg body weight. MR protocol for therapy monitoring: Ist scan before beginning radio-(chemo-)therapy, 2rid scan 2 hrs a~ter the end of the first irradiation, 3rd scan on the 3rd day, 4th scan on the 6th day, Sth scan on the IOth day, last scan on the 21st day. Analysis of therapy monitoring examinations: visual and computer aided (standardized SI values, standard deviation, SI histograms, run length histograms). Follow up of paragangiiomas: MRA 3D FISP 20 40/7, 3D FISP 20 40/18, 2D FLASH 60 sequ. 31/10. 2D TFL phonation studies, Valsalva maneuvres and intensity -vs-time-studies may improve the diagnostic value of N~I of head and neck tumours. Regarding therapy monitoring, changes in the vascular bed of neoplasms during the first minute after an i.v. injection of Gad-DTPA could be identified. This is of prognostic value concerning tumour response to therapy.

I~AGINGOF TU~DURSOF THE H E A D ~ N ~ NECK

The aim of the study was to estimate the value of 3D GE sequences in patients with head and neck neoplasms. For this purpose we compared 3D GE sequences with 2D GE and SE modes. Technique: Magnetom 1.5T, head coils, '~elmholtz-coils", 3D FLASH, FISP, PSIF (with variable TR, TE, flip angle) andMPRage +- Gad-DTPA. The use of 3D GE modes improved the diagnosis of malignant tumours of the skull base, the nasopharynx, the nasal cavities, the paranasal sinuses and the upper parts of the parapharyngea] space with relation to the skull base. Therefore the tumour extent and infiltration may be better appreciated than in conventional 2D SE and 2D GE sequences Using this method, 22 patients with carcinomas were investigated (the sequence comparison was possible). Precise tumour delineation was achieved in 6 of these patients when compared with surgical and histological findings. The 3D sequences most used were FLASH 40 ° with TR of 40ms and the shortest TE (5 to 6 ms). 3D turbo-FLASH (MPRage) with Gad-DTPA was applied in order to shorten the acquisition time by one half and especially to reduce motion artefacts.

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PLANNING AND SIMULATION OF CRANIO-MAXILLOFACIAL SURGERY USING 3-DIMENSIONAL RECONSTRUCTIONS R.Kikinis, D.E.Altobelli, H.E.Cline, W.E.Lorensen, J.MuUiken, F.A.Jolesz Depts. of Radiology and Craniofacial Surgery, Harvard Med. Sch. and Brigham & Women's Hosp., Boston,MA; and General Electric Corp. Res. & Devel.~ Schenectedy,NY

PARTIAL RF ECHO PLANAR IMAGING: INITIAL CLINICAL EXPERIENCE IN THE HEAD AND NECK G.H. Zoarskil, K. Farahanil, P,S. Melki2, F.A. Jolesz2, R.V. Mulkern2, B.A. Jabourl, R.B, Lufkinl. 1University of California, Los Angeles, CA 90024 2Brigham and Women's Hospital, Boston, MA 02115

Purpose. Computer-generated 3D reconstructions from computed tomography (CT) allow interactive visualization and "electronic dissection." It was the goal of this project to develop a computer-based virtual surgical environment for the planning and simulation of craniomaxillofacial procedures. Methods. CI' data (contiguous 3mm slices) of 5 patients with severe craniofaeial malformations were transferred to a workstation equipped with a custom-built accelerator for the manipulation of 3D data sets. Using image processing techniques, 3D reconstructions of the skin and bones were generated. Measurement tools for planning and design were utilized for interactive osteotomies and 3D skin reconstructions. Results. Interactive evaluation of the anatomy provided a more comprehensive understanding of the deformities. Measurements obtained from the 3D reconstructions of bones and soft tissues allowed a quantitative analysis which facilitated osteotomy design, and planning of bone segment position within the virtual surgical environment. Osteotomies simulated included LeFort 1 and 2, madialization of the orbits, and vertical ramus ectomy of the mandible. Conclusion. The ability to plan and optimize complex surgical procedures within a computer-based interactive virtual environment combined with ready quantification improves planning and execution of very complex surgical procedures. When normative 3D morphologic standards become available, art will be aided by engineering in the redesign of patients' craniofaeial malformations. It is the role of the radiologist to provide the imaging-specific knowledge, and collaborate closely with the surgeon in the planning and simulation process.

A partial RF echo planar pulse sequence called DEFAISE, (Dual echo Fast Acquisition Interleaved Spin Echo), developed at the Brigham and Women's Hospital, is now undergoing clinical trials in our department. In this variation of RARE (Rapid Acquisition Relaxation Enhanced) SE imaging, rapid 180° RF pulses generate refocused echoes, producing images of two different weightings in about one third the time of conventional double echo techniques. Nineteen patients with suspected head and neck pathology were studied. Conventional double echo images with TEl=30, TE2=80-90, and TR=2100-2812 were compared to closely matched DEFAISE images (TR +/-100; TE +/-10). Images of comparable quality to those acquired by the long spin echo technique were obtained. In most cases, DEFAISE sequences provided as much, or more information, than matched conventional spin echo images. The advantage of this sequence is an obvious i m p r o v e m e n t in ~canning speed and t h r o u g h p u t . Disadvantages are potential RF heating effects in some larger body areas, and some alterations in contrast. Initial experience with DEFAISE indicates that the new sequence is a promising alternative to conventional T2-weighted SE imaging. Clinical investigations (utilizing this fast spin echo sequence) in MRI-Guided aspiration cytology and medical laser procedures are in progress.

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7 CLINICAL EVALUATION OF MR ANGIOGRAPHY IN THE HEAD AND NECK REGION

Th.J. Vogl, J.O. Balzer, M. Juergens, H. Schedel, J. Lissner MRA findings and anatomical resolution were compared with conventional x-ray angiography. MRA was evaluated reconsidering the clinical requirements for vascular imaging in patients with tumorous lesions. MRA was performed with a 1.5 T Magnetem (Siemens, Erlangen) employing either a circular polarized head coil or a Helmholtz surface coil. Selective arterial and venous MRA was obtained as an add-on scan to conventional imaging with gradientecho sequences (time-of-flight MRA) and presaturation technique. So far 163 patients with various lesions in this region were studied prospectively with arterial (n= 122) and venous (n= 41) MRA. The results were compared by three independent observers and correlated with DSA, if available (n= 43). Comparison with DSA revealed a similar delineation of vascular pathology with head and neck lesions. Especially in the region of the neck and face MRA proved a reduced spatial resolution and limited visualization of vascular structures, whereas MRA of the head improved the diagnostic evaluation. Possible pitfalls of MRA proved to be the diagnostic of stenosis (n=10) or aneurysm (n= 3), leading to an overestimation of these lesions. Other alterations of vessels detected were anomalies (n= 17) such as kinking or coiling of the internal carotid artery, primitive trigeminal artery, occipital sinus and superior jugular bulb, displacement due to tumors (n= 41) and vessel pathology (n= 31) such as aneurysm, stenosis, thrombosis and glomus tumors. Clinical requirements were met in 78% of the cases, avoiding the necessity of additional examination methods. Non-invasive MRA may replace DSA in the evaluation of vascular structures in the head and neck region to some extent. Further modifications of existing soft- and hardware will not only improve imaging quality, but will also expand MRPs role in the diagnosis of vascular structures in the head and neck region.

CT AND MRI IN RELATIONSHIP WITH FUNCTIONAL NECK DISSECTION. A RADIOLOGICAL STUDY OF TOPOGRAPHIC ANATOMY M. De Nicola*, U. Salvolini*, W. Masala °, G. Teatini ° * Neuroradiologia - Osp. Gen. Reg. - ANCONA o Clinica ORL Universit~ Sassari The rationale for functional neck dissection is that radical removal of the contents o£ the spaces where lymphnodes are included may be effective i£ the fasciae enveloping these spaces are wholly elevated and excised. The spaces which must be dissected are the lateral and the paravisceral space. They are separated by the longitudinal sheath of the neck, where the main vessels and nerves are embedded. Ct and MRI are procedures with a high resolution; therefore, they are useful to evaluate preoperatively shape and size o£ the spaces to be entered, as well as site and number of lymphonodes. Anyhow, the study is mainly intended For teaching purposes. The strategy o£ the operation, starting with dissection o£ the lateral space, both below and above the sternomastoid muscle, and ending with the paravisceral space via the longitudinal sheath can be easily explained and demonstrated with CT and MRI direct and reconstructed scans.

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IMAGING OF PARANASAL SINUSES SELECTION OF OPTIMAL TECHNIQUE CS Zee, T Becker,S Destian, J Ahmadi, HD Segall USC School of Medicine

DIAGNOSIS OF LESIONS IN THE NECK: VALUE OF GD-DTPA ENHANCED MR IMAGING M.A. MIKHAEL, E.M. White Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois

Purpose: To determine the optimal technique for imaging the paranasal sinuses. Material and Methods: 42 patients with paranasal sinus disease were evaluated with CT, MRI, Gd-enhanced MRI with fat suppression, angiography and MR angiography. 26 had neoplasms, 14 had inflammatory lesions and 2 had congenital lesions. Clinical information, surgical and pathological results were obtained to correlate with the MRI findings. Results: MRI is superior to CT in differentiating neoplastic from inflammatory processes and demonstrating congenital lesions (e.g. encephaloceles and dermoids) and vascularity of neoplasms. MR angiography is a non-invasive alternative to conventional angiography in the evaluation of neoplastic vascularity. Gd-enhanced MRI with fat suppression is useful in evaluating neoplasms of the paranasal sinuses invading the skull base and orbit. CT is superior to MRI in demonstrating bone erosion or destruction and in evaluating patients with mucormycosis. Conclusion: MRI is the imaging modality of choice for evaluating diseases of the paranasal sinuses. When orbital or skull base invasion is suspected, a Gd-enhanced MRI with fatsuppression should be obtained. A non-contrast CT with bone windows is a useful adjunct for evaluating bony changes or patients in whom mucormycosis is suspected.

10 HIGHRESOLUTIONMR IMAGINGOF THE VESTIBULOCOCHLEARN~RVE M A Brogan,P Schmalbrock The Ohio State University,Columbus,Ohio TwodimensionalFourierWaasfonn(2DFT)spinechomagneticresonanceiraaging has become the preferred modality for evaluating disorders of the facial and vestibulocochlearnerves. However,delineation of the separatecomponentsof the neural structureswithin the internal auditory canal (IAC) has been difficult due to spatial resolutionlimitationsinherent in spinecho teclmiques. Our initial high resolution three dimensionalFourier transform(3DFT) gradient refocusedMR imagesof the temporalbonerevealed subtlefoci of signalvoid within the lumen of the IAC surroundedby cerebrospinalfluid (CSF). Becausethe CSF within the IAC and basal cisteras are contiguous,cardiac pulsationsare readily Wansminedfromthe cerebellopontineangle(CPA)into the IAC lumen. The purpose of this study is to evaluate whetherthe observedsignal voids representthe nerves or whether they are due to CSF motionleading to a disruptionof the steady state spin equilibriumand signal loss. Thin section (1.0-1.5ram) T-1 weightedand steady state imagesof the temporal bone wereobtainedin three orthogonalplanesfromfive normalvolunteersusinga Signa 1.5 Tesla system (General Electric), 3-in or 5-in receive-only surfacecoil, 10-12 cm FOV.256x256 matrix,and 2 NEX. The T-1 weightedimages(60/8.5/40°) were obtained with spoiled gradients. The steady-state images (32/8.5/35°) were obtained withoutrefocusinggradients. In the center of the IAC, in the expected location of the nerves, regions of decreased signal were consistentlyvisualizedon the steady state images,appearing in the axial and coronalplanesas slightlyconvergentlines and as a clusterof dots in the sagittalplane. On the T-1 weightedimages,the overall signalwithinthe IAC is significantlydecreasedcomparedto the steady state images. Thisis expected for stationary or moving CSF due to its long T1. Subtlefoci of increased signal are observedin the central canal. Therefore,diese findingssuggestthat the regionsof signal void COnsistentlyseen on high resolution steady state images represent the facial and vestibalocochiernerves.

PURPOSE: Optimize MR imaging techniques for mdiologieal diagnosis of various neck lesions. CASES: Fifty-eight patients with various benign and malignant lesions of the neck (including the spine) were examined with pr- and post- enhanced MR imaging: Demyelinadng disease of the cervical spinal cord (5 cases), Tumors of spinal cord (8 cases), Cervical herniated discs (pre- and postoperative scans) (10 cases), Bone metastases (20 cases), Carotid body tumor (1 case), Enlarged lymph nodes (7 cases), Tumors of Larynx, Pharynx & Thyroid gland (5 cases), Dissecting aneurysms of the carotid arteries in neck (2 cases). RESULTS: 1) Although chronic demylinating plaques can be seen in T2-weighted non-enhanced MR studies, active demylinating plaques were only detected after enhancement. 2) Spinal cord tumors (primary or mets) are detected and delineated after enhancement. 3) Bone metastases to the spine were masked after enhancement in five out of twelve cases and showed enhancement in four cases. Pre- and post- enhanced MR studies are needed in cases suspected of bone lesions. 4) Tumor extension was better seen and clearly delineated on the post-enhancement studies, an importam information when surgical treatment was considered. 5) Dissecting aneurysms of the carotid arteries in neck are seen better before enhancement. 6) Infections of various structures in neck particularly the spine are better seen after enhancement. 7) Different patterns of enhancement were noticed among various tumor of the neck. CONCLUSION: Both pre- and a post- enhancement MR studies are needed for the radiological evaluation of lesions in the neck. Various patterns of enhancement among various pathological lesions, time of appearance and diagnostic significance will be shown and discussed.

11 TURBOFLASH MRI OF THE INTERNAL AUDITORY CANALS M. Shah, LS. Ross Cleveland Clinic Foundation, Cleveland, Ohio Purpose: To evaluate the utility of TurboFLASH MRI in the assessment of patients with sensorineural hearing loss and compare it with standard spin echo sequences. Materials: Thirty patients with hearing loss were evaluated with pre- and post-gadolinium thin section axial Tl-weighted and T~-weighted axial images with an additional coronal TurbffFLASH sequence post gadolinium. Results: Ten patients had tumors arising from the VIII nerve. Two patients had residual acoustic tumor following previous surgery. All tumors identified on the enhanced axial Tt-weighted images were also seen on the TurboFLASH MRI sequence. Since TurboFLASH acquires volumetric data, images acquired coronally could be reconstructed axially without loss of detail. Also very thin sections (Imm) could be obtained without loss of spatial resolution, as compared to the 3mm sections on the T,-weighted images. Conclusion: TurboFLASI-I MRI (post gadolinium) provides a rapid (approximately 5.5 minutes) method of assessing the internal auditory canals and can replace the axial T,-weighted images (approximately 8 minutes) after contrast. /~dditional benefits include the ability to reconstruct the data from the original set and also acquire very thin sections.

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Scientific Session: Temporomandibular Joint Moderators: W. R.K. Smoker, Richmond, USA and C. Guirado, Barcelona, Spain 11.00 a m - 11.15 am

Keynote address: Imaging of the Temporomandibular Joint: Where we were, where we are, and where we are going W. R.K. Smoker, Richmond, USA

11.15 a m - 12.45 pm

Scientific Papers 12- 20

12.45 p m - 02.00 pm

Lunch

11.15am-12.45 pm Scientific Papers 12-20 012 Temporo-mandibular joint: Value and limits of MR assessment E Vanneroy, G. Payelle, J.E Compere, P. Courtheoux, Caen, France 013 MR imaging of temporomandibular joint disorders T. Nakasato, S. Ehara, M. Sasaki, M. Sone, Y. Tamakawa, A. Hirose, T. Yanagisawa, Morioka, Japan 0t4

The evaluation of temporomandibular joint using fast imaging with steady precession sequence H. Mizuno, H. Mizuno, T. Watabe, A. Heshiki, S. Takaku, T. Sano, M. Yoshida, Saitama, Japan

015 Internal derangement of the temporomandibular joint: Diagnosis with dynamic MR (DMR) versus clinical examination (CE) J.W. Casselman, B. Demot, M. Mommaerts, Brugge, Belgium 016

Enhanced MRI of temporomandibular joint. Is it worthy? M.A. Mikhael, Evanston, USA

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TMJ-retroarticular vascular plexus by MR S.M. Schimmerl, H. Imhof, J. Kramer, E. Piehslinger, W. Slavicek, Vienna, Austria

018

MR Imaging of the temporomandibular joint at 0.5 Tesla A. Bonaf6, J. Haddad, P. George, H. Dumas, P. Bartoli, A. Sevely, C. Manelfe, Toulouse, France

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CT aspects of ehondromatosis of the temporomandibular joint A. Boccardi, Turin, Italy

020 Role of condyle-pterygoid-maxillo-oblique-tomography (CPMOT) in demonstration of sagittal fracture of the mandibular condyle (SFMC) X.G. Wu, M. Hong, Y.H. Li, Beijing, China (Abstract withdrawn)

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Keynote address: Imaging of the Temporomandibular Joint: Where we were, where we are, and where we are going. W.R.K. Smoker Medical College of Virginia, Richmond, Virginia, USA

Normal anatomy The temporomandibular joint (TMJ) is a complex synovial articulation between the mandibular condyle, and the glenoid fossa and eminence of the temporal bone. It is classified as a ginglymoarthrodial (hinge-gliding) joint and essentially comprises two diarthrodial compartments - the superior and inferior joint spaces - completely partitioned by the biconcave, ovoid, fibrous, non-cartilaginous meniscus, or disc. The inferior joint space is the smaller of the two spaces and more tightly reinforced by a fibrous capsule than the superior joint space. The meniscus is thin in the center (central or intermediate zone) (1 mm) and thicker peripherally (2.8 mm - posterior band; 2.0 mm - anterior band). The meniscus is attached anteromedially to the superior belly of the lateral pterygoid muscle, anteriorly it blends with the joint capsule, and medially and laterally it attaches to the mandibular condyle. The posterior attachment of the meniscus, composed of two lamellae, is termed the bilaminar zone (retrodiscal tissue), a neurovascularly rich region posterior to the joint. The posterosuperior lamella is formed by the elastic ligamentous insertion of the meniscus into the tympanic bone. The posteroinferior lamella is formed by the non-elastic, fibrous, ligamentous insertion into the cervical region of the mandibular condyle. It is stretching or tearing of this fibrous non-elastic posteroinferior ligament that leads to meniscus displacement. The sensitive neurovascular bilaminar tissue then becomes interposed between the mandibular condyle and articular eminence, producing an inflammatory response, joint dysfunction, and pain. Pathologically, the bilaminar zone may become pale, thin, loose, and inelastic (atonic).

the meniscus snaps into normal position may produce a clicking sound, associated with both opening and closing the mouth. In anterior displacement without capture, the meniscus remains anterior to the mandibular condyle in all positions and may produce mechanical obstruction to condylar translation ("locked condyle").

Demographics It is estimated that between 4 and 28% of the population is affected by signs and symptoms of TMJ dysfunction. Women outnumber men by a ratio of 8 : 1, reasons for which are uncertain. Predisposing factors to TMJ dysfunction are multiple and include congenital anomalies (occlusal abnormalities), trauma, endotracheal intubation, intra-oral dental procedures, arthritis, bruxism, stress, and a history of previous orthodontia. Signs and/or symptoms of TMJ dysfunction include local pain, headache, earache, joint sounds (clicking or crepitus), tenderness, limitation of jaw opening, deviation of the jaw from midline upon maximal opening, and lateral jaw movements. Joint clicking may be present in anterior meniscus dislocation, both with and without capture and should not be considered to imply reduction of the displaced meniscus. The presence of internal TMJ derangement (anterior meniscus position) has been reported in up to 32°7o of asymptomatic patients. In one study, abnormal meniscus position was highly correlated with a previous history of changes in occlusion (orthodontics and/or multiple extractions) and has led to the suggestion, by some, that baseline imaging studies be obtained in all patients prior to the institution of orthodontic treatment.

Functtonal and non-functional anatomy

Imaging

In the closed mouth position (teeth are in centric occlusion), the thicker, posterior, band of the meniscus should normally be positioned over the highest point of the mandibular condyle 0 2 o'clock position) and the thin, central, zone should lie between the condyle and posterior slope of the articular eminence. When the mouth is opened, the mandibular condyle and meniscus normally translate in concert, anteriorly, under the articular eminence, but the meniscus should never slide over the anterior lip of the condyle. In addition to translation, the condyle also has a hinge-like motion which, in and of itself, allows up to 25 mm of mouth opening. The most commonly identified internal derangement of the TMJ is anterior displacement of the meniscus, with or without reduction (capture). In anterior displacement with capture, the meniscus is positioned in an anterior location, relative to the mandibular condyle, in the closed mouth position, such that the condyle rests on the posterior band or bilaminar (retrodiscal) tissue. Upon opening the mouth, the condyle translates anteriorly, under the posterior band, and assumes a relatively normal position on the central zone of the meniscus. The point at which

Plain Radiography and Tomography Transcranial views of the TMJ performed in the submentovertex and parasagittal open- and close-mouthed positions may reveal degenerative joint changes but are reportedly positive in only 5-10°70 of patients with internal derangement. The position of the mandibular condyle within the glenoid fossa is relatively unreliable for internal derangement diagnosis. Tomography provides better demonstration of degenerative TMJ disease than do plain radiographs. Tomography, however, exposes the patient to a high radiation dose and offers no evaluation of the meniscus, either directly or indirectly. Some still advocate the use of routine plain radiographs and tomography for evaluation of side-to-side skull base and condylar symmetry, condyle position within the glenoid fossa, and the presence or absence of degenerative bony changes.

Arthrotomography Arthrotomography, capable of indirectly evaluating the softtissue components of the TMJ including meniscus position,

S 54 function, and morphology, is positive in 7 5 - 8 0 % of patients with suspected internal TMJ derangements. The incidence of abnormal studies in asymptomatic patients is unknown. Many methods of arthrography have been advocated including singlecontrast arthrography of the inferior joint space or both the inferior and superior joint spaces, as well as double-contrast arthrography. Images have been recorded on plain radiographs, tomograms, and videotape. The main advantages of arthrotomography are that it permits assessment of joint function dynamics, accurately depicts the anatomic relationships of the meniscus to the condyle and the temporal bone, and is relatively inexpensive. Meniscal perforations are ideally demonstrated with lower joint space, single-contrast arthrography by visualization of contrast filling both the superior and inferior joint spaces. Additionally, of all the possible imaging modalities, arthrotomography best depicts joint adhesions. The disadvantages of arthrotomography include the inability to accurately depict osseous pathology, a substantial radiation dose, invasiveness of the procedure, and inability to directly demonstrate the soft-tissue components of the articulation. Complications associated with arthrotomography include contrast extravasation, post-procedural joint pain and infection, and transient facial nerve palsies. C o m p u t e d Tomography

CT has been shown to provide significantly more information than plain radiographs and conventional tomography and to be almost as accurate as arthrotomography for demonstration of meniscal dislocation. In addition, CT is non-invasive and requires less radiation exposure than does arthrography. Disadvantages of this technique include the paucity of information obtained concerning meniscus morphology (i.e., perforation and maceration), the inferior soft-tissue contrast resolution and anatomic detail garnered when compared to MR imaging and the patient discomfort incurred when obtaining direct sagittal images of the TMJ. The use of CT scanning for the assessment of TMJ internal derangements has decreased dramatically since the advent of surface coil MR imaging. CT remains superior to MR for evaluation of osseous abnormalities when fine osseous detail is required and for evaluation of osseous mandibular deformities. Magnetic Resonance Imaging

Surface coil MR imaging has rapidly surpassed CT and arthrography as the imaging modality of choice for most patients with suspected uncomplicated internal derangements of the TML It is non-invasive, requires no ionizing radiation, permits direct visualization of the meniscus and joint structures, and orthogonal, multiplanar images may be obtained directly. A vast array of MR imaging protocols have been proposed. Most commonly an axial localizing sequence is obtained, followed by sagittal Tl-weighted spin echo sequences in both the closed- and open-mouthed positions. The exact place of coronal TMJ MR imaging is somewhat controversial. Coronal images should be obtained in all patients in whom the meniscus is not well-demonstrated on sagittal images. Some advocate the use of coronal images, in conjunction with sagittal imaging, for evaluation of all osseous anatomy and pathology (fractures, abnormal marrow, etc...). Because of the high frequency of medial or lateral meniscus displacements (26070 in one series) some recommend routine coronal imaging for all patients. S o m e TMJ imagers recommend the acquisition of T2weighted spin-echo sequences for demonstration of edema

behind the meniscus or fluid within the joint space(s), especially in patients with a history of TMJ trauma. The main limitation of TMJ MR imaging at present is its lack of real-time dynamic capability. To overcome this limitation, some have advocated the use of sequential partial flipangle GRASS (gradient recalled acquisition in the steady state) images, obtained during incremental degrees of mouth opening, which permit both fast scanning and study of functional joint dynamics. Others have reported the efficacy of fast, low-angle shot (FLASH) MR imaging sequences to obtain pseudodynamic TMJ images. In addition to its lack of dynamic capabilities, MR remains incapable of depicting meniscal perforations, adhesions, and most loose bodies. Arthrotomography continues to be the procedure of choice for demonstration of these uncommon abnormalities. Radionuclide Imaging

When internal derangements of the TMJ is present, the bone scan will become positive before conventional radiographs or tomography. This screening test has also been reported to be more sensitive than either CT or MR. It can be performed quickly, with minimal radiation, and be used to establish objective evidence for organic disease of either the TMJ or areas of regional anatomy.

Treatment options Currently, treatment options available for internal TMJ derangements include: l) Arthroscopy - the superior joint space is entered and irrigation is performed to lyse adhesions. In one study 80% of patients demonstrated improved mobility and 92% reported decreased pain following arthroscopy, despite the fact that 92% of patients continued to demonstrate anterior meniscus displacement. 2) Meniscoplasty - the meniscus is surgically repaired and repositioned within the joint space (plication). Reports in the literature concerning correlation between symptomatology and post-operative disc position are conflicting. Some authors find symptomatic improvement associated with improvement in disc position while others find no such relationship. It would appear that the correlation or lack thereof may be dependent on the exact type of meniscoplasty performed and the surgeon performing it. Radiologists, therefore, would be well-advised to examine their patient population for correlation between symptomatology and post-operative disc position before attempting to interpret post-meniscoplasty imaging studies. While MR imaging is capable of determining post-operative disc position and the status of marrow within the condyle, it is still incapable of detecting disc perforations and joint adhesions, two conditions that may be seen more frequently in the post-operative TMJ than in the native joint. Arthrograph~; therefore, may be a useful alternative to MR in imaging the post-operative TMJ when such complications are suspected. 3) Menisectomy and disc replacement - the meniscus is surgically removed and replaced with an autogenous or a alloplastic implant designed to function as a prosthesis. Alloplastic implants may be composed of silastic or a laminent of protoplast and non-porous teflon. On MR imaging, both implants appear as elongated regions of hypointense signal lining the temporal fossa on Tl-weighted images. Frac-

$55 tured and dislocated implants are successfully identified on both CT and MR imaging, Unfortunately, both the silastic and Protoplast-Teflon implants lead to a significant inflammatory reaction and destructive joint changes, reported to occur in 6 - 7 5 % of patients. Pathologically this is produced by a foreign body, granulomatous-type reaction. Because of the severity of this complication, the use of alloplastic implants has been greatly reduced in recent years. 4) R i b graft replacement o f the mandibular condyle - Currently acceptable indications for rib graft replacement of the mandibular condyle include: 1) ankylosis; 2) aplasiahypoplasia; 3) neoplasia; 4) infection; 5) osteoarthritis; 6) rheumatoid arthritis; 7) trauma; 8) iatrogenic disease (avascular necrosis...); and 9) idiopathic condylar resorption. CT remains the best modality for imaging patients following this procedure because of its excellent graft bone detail. CT, however, is only minimally helpful in evaluating the cartilaginous cap. The most frequent long-term complication of this procedure is degenerative joint disease and the potential for joint ankylosis is high. At 12 months following surgery, even asymptomatic patients have been shown to exhibit mild degenerative changes of the joint. 5) Total j o i n t replacement - the condyle is replaced by a metallic prosthesis and the temporal fossa is replaced with a synthetic implant. Because of artifacts produced by the implant metal, post-operative imaging is confined to plain film radiography and tomography. Where do we go from here?

The introduction of newer imaging modalities has expanded our understanding of TMJ anatomy, both normal and pathologic. Prior to obtaining this information there was the optimistic suspicion that a high correlation between anatomic abnormality and symptomatology existed. Recent studies demonstrate that such a correlation is not always present. Such findings suggest that we have a long way to go before we truly understand the pathophysiology of this complex joint. Enhancing our imaging capabilities by such things as realtime MR cine techniques and, perhaps, even spectroscopic MR analysis, can hopefully help in this understanding. References

Anderson QN, Katzberg RW (1984) Loose bodies of the temporomandibular joint: Arthrographic diagnosis. Skel Radiol 11:42-46 Bell KA, WaltersPJ, Stephan MT, Hudson SB, Hanson TM (1984) High resolution scanning of the temporomandibular joint. GE CT Clinical Symposium, Vol 7; No 11 Burnett KR, Davis CL, Read J (1987) Dynamic display of the temporomandibular joint meniscus by using "fast-scan" MR imaging. AJR 149:959-962 Christiansen EL, Moore RJ, Thompson JR et al. (1987) Radiation dose in radiography, CT, and arthrography of the temporomandibular joint. AJR 148:107-109 Conway WF, Hayes CW, Campbell RL (1988) Dynamic magnetic resonance imaging of the temporomandibular joint using FLASH sequences. J Oral MaxiUofac Surg 46:930-937 Conway WF, Hayes CW, Campbell RL, Laskin DM (1989) Temporomandibular joint motion: Efficacy of fast low-angle shot MR imaging. Radiology 172:821-826 Drace JE, Enzmann DR (1990) Defining the normal temporomandibular joint: Closed-, partially open-, and open-mouth MR imaging of asymptomatic subjects. Radiology 177:67-71 Drace JE, Young SW, Enzmann DR (1990) TMJ meniscus and bilaminar zone: MR imaging of the substructure-diagnostic landmarks and pitfalls of interpretation. Radiology 177:73-76

Harms SE, Wilk RM (1987) Magnetic resonance imaging of the temporomandibular joint. RadioGraphics 7:521- 542 Harms SE, Wilk RM, Wolford LM et al. (1985) The temporomandibular joint: Magnetic resonance imaging using surface coils. Radiology 157:133-136 Helms CA, Kaban LB, McNeill C, Dodson T (1989) Temporomandibular joint: morphology and signal intensity characteristics of the disc at MR imaging. Radiology 172:817-820 Helms CA, Kaplan PA (1990) Diagnostic imaging of the temporo-mandibular joint: Recommendations for the use of various techniques. AJR 154:319-322 Helms CA, Vogler JB, Morrish RB et al. (1984) Temporomandibular joint internal derangements. CT diagnosis. Radiology 152:459- 462 Herzos S, Mafee M (1990) Synovial chondromatosis of the TMJ: MR and CT findings. AJNR 11:742-745 Kaplan PA, Helms CA (1989) Current status temporomandibular joint imaging for the diagnosis of internal derangements. AJR 152:697-705 Kaplan PA, Reiskin AB, Tu HK (1987) Temporomandibular joint arthrography following surgical treatment of internal derangements. Radiology 163:217-220 Kaplan PA, Tla HK, Sleder PR et al. (1986) Inferior joint space arthrography of normal temporomandibular joints. Reassessment of diagnostic criteria. Radiology 159:585-589 Kaplan PA, Tu HK, Williams SM et al. (1987) The normal temporomandibular joint: MR and arthrographic correlation. Radiology 165:177-178 Katzberg RW (1989) Temporomandibular joint imaging. Radiology 170:297- 307 Katzberg RW, Bessette RW, Tallents RH (1986) Normal and abnormal temporomandibular joint. MR imaging with surface coil. Radiology 158:183-189 Katzberg RW, Dolwick MF, Bales DJ, Helms CA (1979) Arthrotomography of the temporomandibular joint: New techniques and preliminary observations. AJR 132:949-955 Katzberg RW, Dolwick MF, Helms CA et al. (1980) Arthrotomography of the temporomandibular joint. AJR 134:995-1003 Katzberg RW, Keith DA, Guralnick WC et al. (1983) Internal derangements and arthritis of the temporomandibular joint. Radiology 146:107-112 Katzberg RW, O'Mara RE, TallentsRH, Weber DA (1984) Radionuclide skeletal imaging and single photom emission computed tomography in suspected internal derangements of the temporomandibular joint. J Oral Maxillofac Surg 42:782-787 Katzberg RW, Westesson PL, Tallents RH et al. (1988) Temporomandibular joint: MR assessment of rotational and sideways disc displacements. Radiology 169:741-748 Khoury MB, Dolan E (1986) Sideways dislocation of the temporomandibular joint meniscus: The edge sign. AJNR 7:869-872 Kneeland JB, Ryan DE, Carrera GF et al. (1987) Failed temporomandibular joint prosthesis: MR imaging. Radiology t65:179-181 Leopard PJ (1984)Anterior dislocation of the temporomandihular disc. Br J Oral Max Surg 22:9-17 Lieberman JM, Bradrick JP, Indresano AT et al. (1990) Dermal grafts of the temporomandibular joint: Postoperative appearance on MR images. Radiology 176:199-203 Miller TL, Katzberg RW, Tallents RH, BesselleRW, Hayakawa K (1985) Temporomandibular joint checking with non-reducing anterior displacement of the meniscus. Radiology 154:121-124 Nance EP, Powers TA (1990) Imaging of the temporomandibular joint. Radiol Clin North Am 28:1019-1031 Rao VM, Farole A, Karasick D (•990) Temporomandibular joint dysfunction: Correlation of MR imaging, arthrography, and arthroscopy. Radiology 174:663-667 Rugh JD, Solberg WK (1979) Psychological implications in temporomandibular pain and dysfunction. In: Zarb GA, Carlsson GE (eds) Ternporomandibular Joint Functionand Dysfunction. Copenhagen. C.V. Mosby Co., pp 239-268 Schellhas KP (1989) Temporomandibular joint injuries. Radiology 173:211-216 Schellhas KP, Wilkes CH (1989) Temporomandibular joint inflamma-

S 56 tion: Comparison of MR fast scanning with T1- and T2-weighted imaging techniques. AJNR 10:589-594 Schellhas KP, Wilkes CH, Deeb ME et al. (1988) Permanent proplast temporomandibular joint implants: MR imaging of destructive complications. AJR 151:731-735 Schellhas KP, Wilkes CH, Fritts HM et al. (1989) MR of osteochondritis dissecans and avascular necrosis of the mandibular condyl~ AJR 152:551-560, AJNR 10:3- I2 Schellhas KP, Wilkes CH, Fritts HM et al. (1987) Temporomandibular joint: MR imaging of internal derangements and postoperative changes. AJNR 8:1093-1101 Schellhas KP, Wilkes CH, Omlie MR et al. (i988) The diagnosis of temporomandibular joint disease: Two-compartment arthrography and MR. AJNR 9:579-588 Schwaighofer BW, Tanaka TI', Klein MV et al. (1990) MR imaging of the temporomandibular joint: A cadaver study of the value of coronal images. AJR 154:1245-1249 Shellock FG, Pressman BD (1989) Dual-Surface-Coil MR imaging of bilateral temporomandibular joints: Improvements in the imaging protocol. AJNR 10:595-598 Solberg WK, Woo MW, Houston JB (1979) Prevalence of mandibular dysfunction in young adults. J Am Dent Assoc 98:25-34 Stanson AW, Baker HL Jr (1976) Routine tomography of the temporomandibular joint. Radiol Clin North Am 14:105-127

Thompson JR, Christiansen E, Hasso AN, Hinshaw DB (1984) Temporomandibular joints: High resolution computed tomographic evaluation. Radiology 150:105-110 Thompson JR, Christiansen E, Sauser D et aL (1984) Dislocation of the temporomandibular joint meniscus: Contrast arthrography vs. computed tomography. AJNR 5:747-750, AJR (1985) 144:171-174 Walter E, Huls A, Schmelzle R et al. (t988) CT and MR imaging of the temporomandibular joint. RadioGraphics 8:327-348 Westesson PL, Bronstein SL (1987) Temporomandibular joint: Comparison of single and double-contrast arthrography. Radiology 164:65 - 70 Westesson PL, Bronstein SL, Liedberg J (1986) Temporomandibular joint: Correlation between single-contrast video arthrography and postmortem morphology. Radiology 160:767-771 Westesson PL, Katzberg RW, Tallents RH et al. (1987) CT and MR of the temporomandibular joint: Comparison with autopsy specimens. AJR 148:1165-1171 Westesson PL, Katzberg RW, Tallents RH et al. (1987) Temporomandibular joint: Comparison of MR images with cryosectional anatomy. Radiology 164:59-64 Westesson PL, Rohlin M (1984) Diagnostic accuracy of double-contrast arthrotomography of the temporomandibular joint: Correlation with postmortem morphology. AJNR 5:463-468

$57

12

13

F. VANNEROY*, G. PAYELLE*, J.F. COMPERE**, P. COURTHEOUX* Departments of MRI and Maxillo-Facial S u r g e r y * *

M R IMAGING O F T E M P O R O M A N D I B U L A R JOINT D I S O R D E R S T.Nakasate, S.Ehara, M.Sasaki, M.Sone, Y.Tamakawa, A.Hirose, T.Yanagisawa lwate Medical University School of Medicine

CHU de CAEN - Av. de l a C o t e 1 4 0 3 3 CAEN CEDEX (FRANCE)

PURPOSE

: Improvement

de N a c r e

of T M J ' s a s s e s s m e n t w i t h

MATERIAL AND METHOD : 50 patients presenting w i t h i n t e r n a l d e r a n g e m e n t u n d e r w e n t MRI (1,5 T CGR-GE) w i t h a s i n g l e s u r f a c e coil. S a g i t t a l TI w e i g h e d sequences (spin-echo) with closed and open m o u t h w e r e o b t a i n e d . K i n e m a t i c MRI w e r e p e r f o r m e d w i t h an a n i m a t i o n d i s p l a y of sequential o p e n i n g images o f TMJ ( f r o m c l o s e d

to

fully

opened mouth p o s i t i o n ) .

RESULTS : I n 30 p a t i e n t s , anterior meniscus d i s p l a c e m e n t ( o n one o r b o t h s i d e s ) was f o u n d . 5 patients underwent surgery with accuracy between radiological and s u r g i c a l findings in all cases, CONCLUSION : The a u t h o r s emphasize the value and limits of the assessment of internal d e r a n g e m e n t w i t h MRI and MR c i n e - s i m u l a t i o n .

To correlate the function and morphology of T M J disorders, w e analyzed T M J arthrosis b y meaxls of correlating the degree of displacement and type of deformity of the menisci having possible reduction. Changes in the shape and motion after splint therapy were also monitored. Included in this study are 66 patients having T M J disorders. 0.5 superconductive M R unit was used with either the image with spin echo technique, or 14-16 phase dynamic images with gradient echo technique. Based on these M R findings, 103 joints were classified as follows: internal derangement (56 joints), osteoarthrosls (18), posttraumatic arthrosis (2), failed prosthesis (2), norraal (25). Displacement of the meniscus was observed in 72 joints: anterior (62), lateral or medial (7), and posterior (3). In 72.6% of the anterior displacement cases, no reduction was observed. Shrinkage type deformity of the menisci was frequently observed in the cases with closed lock, suggesting loss of elasticity of the posterior attachment as a cause of closed lock. Splint therapy improved relationship between the meniscus and mandibular condyle only in 5 of the 15 cases, and this correlated well with the clinicaloutcome. M R is a m o d e of choice in evaluating the morphology and function of TMJ, and in monitoring splint therapy.

14

15

THE EVALUATION OF TEMPOROMANDIBULAR JOINT USING FAST IMAGING WITH STEADY PRECESSION SEQUENCE

INTERNAL DERANGEMENT OF THE TEMPOROMANDIBULAR JOINT: DIAGNOSIS WITH DYNAMIC MR (DMR) VERSUS CLINICAL EXAMINATION (CE). J.W. Casselman*, B. Demur**, M. Mommaerts** Department of Radiology* and Maxillofaeial Surgery** A.Z. St. Jan Brugge, Belgium

HID. MIZUNO 1, HIT. MIZUNO 1, TA, WATABE 1 , AT. HESHIKI 1, SU TAKAKU 2, TU SANO 2, and MA YOSHIDA 2 Department of radiology I and oral surgery 2, Saitama Medical School, JAPAN To evaluate the Temporomandibular joints ( TMJ ), fast imaging with steady precession sequence (FISP) was performed on 70 subjects including 15 asymptomatic normal volunteers. All subjects were studied on superconducting MR unit with 1.5 tesla. 2-ram sagittal plane was obtained with FISP 2D or 3D acquision technique. Pulse sequence of FISP was TR/TE 30/12msec, and flip angle with 40 degrees. In order to analyze the functional anatomy, cine MR/using FISP 2D was also obtained in some volunteers and patients. FISP 3D images of the TMJ made it possible to evaluate disk components, joint cavity fluid, and adjacent vessels. In the normal volunteers, size and location of the disk, condylar shape were well demonstrated. While, 55 patients showed abnormal disk displacement, deformity, adhesion, perforation, and condylar deformity due to osteoa~ritis, fracture, and avascular necrosis. On cine MRimaging using FISP 2D, the patients with closed lock showed abnormally anterior disk displacement without reduction during opening and closing of the mouth. In conclusion, FISP 2D or 3D images reflected the static and functional anatomy of the TMJ in detail. Disk disorders of the TMJ were welt demonstrated as abnormal displacement, deformities, and increasing disk intensity.

The aim of this study was to find out in how many temporomandibular joints (with possible internal derangements), DMR can confirm or correct the clinical diagnosis and vice versa. Both joints were always examined in order to detect bilateral pathology and "overlooked" opposite side pathology 70 patients (140 joints), in which the clinical diagnosis was doubtful or in which joint surgery was considered, were selected. These patients underwent a DMR study on a i Tesla system, using a surface coil and a very short Tl-weighted sequence (repeated 6 times during 6 phases of progressive mouth opening). DMR confirmed the clinical diagnosis in 62% of the joints and corrected the diagnosis in 23% of the joints. Bilateral pathology was present in 33 patients. The most important benefit of DMR was that it detected anterior dislocations without reduction (AD-R) missed during CE (17 joints), all but one of these clinically overlookedAD-R's occured in patients with bilateral pathology. In 21 joints the clinical diagnosis was anterior dislocation with reduction while the DPIR study was normal. We conclude that the use of both good CE and DMR provides us with an exact diagnosis in 85% of the cases. The major benefit of DMR is the detection of clinically "overlooked" opposite side pathology. It is not clear whether CE (anterior dislocation with reduction) or DMR (normal TMJ function) gives the correct diagnosis in the remaining 15% of the cases, but arthrographic confirmation is superfluous because therapy will nevertheless be conservative.

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16 ENHANCED MRI OF TEMPOROMANDIBULAR JOINT. IS IT WORTHY? M.A. Mikhael Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois

17 TMJ- RETROARTICULAR VASCULAR PLEXUS BY MR S.M. SCHIMMERL, H. IMHOF, J. KRAMER, E. PIEHSLINGER, W. SLAVICEK MR- INSTITUTION VIENNA UNIVERSITY

PURPOSE: The purpose of this study is to evaluate the benefits of Gd-DTPA enhanced MR of the temporomandibular joint versus the nonenhanced studies, a question raised because of the high cost of contrast material added to the cost of MR. CASES: We studied 118 cases of suspected temporomandibular joint problems with MR scans; 49 studies were abnormal. The last 27 abnormal cases were studied before and after gadolinium injection, RESULTS: The abnormal studies include 5 cases of anterior condylar subluxation, 18 cases of anteromedial disc displacement without reduction, 20 cases with anteromedial displacement with reduction, 2 cases of fractured mandible and 1 of them showed nonunion, pseudoarthrosis and anteromedial displacement, 2 cases of destroyed frozen joint with adhesions, and two eases of cysts of disc. MRI was found to have a specificity of 100% in the diagnosis of abnormal derangements of the temporomandibular joint as correlated with surgical and/or videoarthrography findings. However, the diagnosis of perforation of meniscus was missed in 8 out of 11 cases. Although postenhanced MR showed clear delineation of the capsule and ligaments better than the nonenhanced MR scans; no added significant diagnostic informations were obtained that could change the diagnosis and subsequently the treatment of these patients. CONCLUSION: ff the fibrous capsule and the ligamentous attachments are to be radiologically evaluated, we believe that gadolinium enhancement should be used for better delineation. If the study is mainly for the position and the pathological abnormalities of the interarticular meniscus and bony structures, noncontrast enhanced MR is the study of choice.

In 1955 Zenker first described a pad of veins in the retrodiskal area of the temporomandibular joint, which engorges with blood, filling the space vacated by the mandibular condyle on mandibular opening. Purpose of our study was to show this neurovascular zone by MR. 5 joints of healthy volunteers and 35 joints of 30 patients with clinical diagnosis of internal derangement were examined by MR (0.5 T). We used T1weighted images in parasagittat and coronal plans in closed and open mouth position before and after i,v. injection of contrastmedium. In all cases (n= 40) it was possible to enhance the retrodiskal pad in openmouth position, while in closed-mouth position no increase of indensity was measureable. The elastic fibers of the bilaminar zone and the disk itself could be better identified. The retrodiska[ vascular pad is important for the function of the TMJ. The use of contrastmedium enables to det[ne the posterior band and laminae of the bilaminar zone easier and perhaps reveals substructural changes in TMJ dysfunktion.

18

19

ME IMAGING O F T I ~ TEb~OROMAMDIBULARJOINT AT 0 . b T E S T L A 6" Bonaf~, J. Haddad, P. George, H. Dumas, P. Bartoli, A. Sevely, C. Manelfe. Neuroradiology Department, 31059 Toulouse C~dex. 140 patients, complaining of temporomandibular joint (ATM) dysfunction were examined at 0.5 T. with gradient echo, TI, weighted sequences. Anterior subluxation (22 %) and meniscal dislocation (30 %) were the most frequent pathologic findings. Meniscal high signal focal intensities were found in 20 % of the oases and may represent myxoid degenerative lesions. A perforation of the posterior disc attachment was noted in 8 cases (5 %). Adhesions of the superior joint space (12 %) was suggested by meniscal locking and reinforcement of the low signal intensity of the bilaminar zone. MRI appears suitable to study TMJ disorders and reduce the need for arthrography.

fYI"ASPECTS OF CHONDROMATOSIS OF THE TEMPOROMANDIBULAR JOINT A. Boccardi Cattedra di Radiologia della Facoltc~di Medicina e Chirurgia di Novara Chondromatosis is a rare condition characterised by intraarticular proliferation of a small cartilage nodules originating in the synovial membrane. Occurence in the temporomandibular joint (TMJ) is execeptional and the diagnosis is problematical; the recent employment of CT, however, has allowed the presence of nodules to be clearly demonstrated, This case report describes two patients with chondromatosis of the TMJ diagnosed by CT. The first was a 42-yr-old woman with preauricular pain, Politomography had disclosed small radiopaque formations close to

20

the right condyle, CT revealed the presence of a large number of loose bodies surrounding the condylar head like a crown; all these

Abstract withdrawn

bodies displayed signs of ossification. The second was a 61-yr-old man with TMJ pain exacerbated by opening of the mouth. Politomography revealed the presence of a small radiopaque formation anterior to a flattened condyle, CT disclosed considerable irregularity of the glenoid fossa and the condylar head; two ossified loose bodies in front of the condyle displayed irregular border and were surrounded by a sclerotic rim.

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Opening Session ICHNR and ESNR

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Opening Address: A. Valavanis, Congress President Welcome Address: P. Kleihues, Professor of Neuropathology and Dean of the Medical Faculty of the University of Zurich

02.10 p m - 02.35 pm

Opening Lecture: Neuroradiology and Head and Neck Radiology in the Decade of the Brain D.C. Harwood-Nash, Toronto, Canada

Neuroradiology and Head and Neck Radiology in the Decade of the Brain D.C. Harwood-Nash

Professor of Neuroradiology, Hospital for Sick Children and the University of Toronto, Canada The remarkable advances in imaging and procedures within the study of anatomy and diseases of the central nervous system, head and neck, and the spine has lead to a level of clinical sophistication virtually unmatched in all of medicine. Not only has their application been revolutionary, but also has their development been intimately stimulated and directed by neuroradiologists and head and neck radiologists. The Decade of the Brain is a propitious moment, therefore, to place these innovations in a practical perspective; to plan priorities in research and to promote greater investigative endeavors; and to consolidate radiologists and researchers of these fascinating organ systems into an effective worldwide collegium.

The present day strengths of these persuasions must be consolidated in all their facets, continue to mature, and they must ensure a leadership role within the Neuroscience community with respect to research and education in particular. This innovative combined meeting is an appropriate geographical and temporal starting point in this context. A personal perspective and proposal will be delivered as a practical foundation not only for this decade but into the next century. The ability and enthusiasm of the many outstanding younger colleagues must be fostered and encouraged within a carefully planned and constituted scientific and academic environment.

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Special Focus Session (ASHNR, ESHNR, ESNR) Special Focus Session Petrous Bone and Central Skull Base Chairman: U. Fisch, Zurich, Switzerland

02.45 p m - 03.15 pm

Imaging of Petrous Bone Lesions J. Vignaud, Paris, France

03.15 p m - 03.45 pm

Imaging of Central Skull Base Lesions A.N. Hasso, Loma Linda, USA

03.45 p m - 04.15 pm

Coffee Break

04.15 pm-04.35 pm

Vascular Anatomy of the Skull Base and Treatment of Vascular Lesions P. Lasjaunias, Paris, France

04.35 pm-04.55 pm

Interventional Neuroradiology of Petrous and Central Skull Base Tumors A. Valavanis, Zurich, Switzerland

04.55 pm-05.30 pm

Otoneurosurgery of Petrous Bone Lesions U. Fisch, Zurich, Switzerland

05.30 pm-06.05 pm

Direct Microsurgicat Approach to Tumors and Vascular Lesions of the Cavernous Sinus V.V. Dolenc, Lubljana, Yugoslavia

06.05 p m - 06.15 pm

Discussion

Imaging of Petrous Bone Lesions J. Vignaud, C. Pharaboz H6pital du val de grfice, Paris, France Imaging of petrous bone tremendously improved within the last past three decades. Plain films and stereoradiography totally disappeared to the benefit of tomography. Conventional tomography (linear, then multidirectional), is now replaced by Computerized Tomography (CT) and Magnetic Resonance Imaging (MRI). These two procedures are complementary. CT may depict exquisite detailed anatomy of bony modifications, and soft tissue masses, but with a poor specificity of the lesion. MRI, using various sequences depending on the pathology, and gadolinium injection provides a very accurate visualization of

tumoral masses, vessels, and an approach to tissue characterization. The role of CT and MRI is different, depending on the pathology. In this presentation, we would like to emphasize the state of the art, regarding techniques, sensitivity and specificity of CT and MRI, in the main lesions of the temporal bone, including malformations, infections, traumatism and otosclerosis using precise examples. The algorhithm of the procedures will be discussed in all the cases.

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Imaging of Central Skull Base Lesions A.N. Hasso Loma Linda University School of Medicine, Loma Linda, California, USA The base of the skull is composed of a variety of tissues including fat, osseous structures, cranial nerves and soft tissues in every conceivable arrangement. Delineating the boundaries and interfaces of these different tissues is a difficult task, but one which MRI is able to achieve more effectively than other previous imaging or radiographic techniques. MRI is superior to CT in identifying bone marrow disease and in demonstrating evidence of a neoplasm infiltrating through the dural boundaries of the brain. MRI is less helpful than CT in visualizing cortical bony detail. This is particularly a problem in thin bones, such as the anterior cranial fossa, where the marrowless bone is nearly invisible on MRI. Most of the time, this lack of bone signal with MRI is an advantage since there are no beam hardening artifacts as seen in CT images performed near dense bony structures. I m a g i n g

t e c h n i q u e s

The routine use of paramagnetic enhancing agents has made MRI the primary mode of investigation in most cases. Such enhanced T 1-W images are useful for differentiating tumor from muscle. Tumors spreading along the cranial nerves into the cavernous sinus or brainstem are readily demonstrated on these enhanced scans. T2-W images are useful for demonstrating edema adjacent to sites of tumor spread in both the extra- and intracranial compartments. T2-W scans are also essential for showing evidence of denervation atrophy of the muscles indicating chronic dysfunction of one or more cranial nerves. Unenhanced T 1-W images are useful for demonstrating MR signal abnormalities and morphologic alterations which may aid in the differential diagnosis of lesions. Special new MR techniques such as fat saturation and threedimensional (3 D) images have further refined the evaluation of the skull base. We now routinely utilize 3 D magnetic resonance angiography (MRA) to evaluate the vascularity of central skull base tumors along with suspected displacement or encasement of the major vessels and/or dural sinuses of the central skull base. A n a t o m y

Pathology

Table.

Congenital and Developmental Lesions - Malformations Basal encephalocele - Transalar encephalocele - Neurofibromatosis - Sphenoid dysplasias - Plexiform neurofibroma -

Traumatic Lesions - Fractures Pseudoaneurysms C-C fistulas -

Inflammatory Lesions Osteitis and osteomyelitis - Typical form - Atypical form -

Metabolic and Dysplastic Lesions Fibrous dysplasia Osteopetrosis Histiocytosis X -

-

Cranial Nerve Tumors Neurinoma (schwannoma and neurofibroma) Cavernous sinus - Trigeminal ganglion and trigeminal nerve Geniculate ganglion and facial nerve - Perineural spread of head and neck neoplasms -

-

-

Skull Base Tumors - Neuroepithelial neoplasms - Chordoma - Congenital cholesteatoma - Mesenchymal neoplasm Osteocartilagenons tumors Hemangioma - Sarcoma/lymphoma - Plasmacytoma Giant cell tumor Extension of regional neoplasms Sinonasal - Nasopharynx - Upper aerodigestive Parotid gland - Temporal bone -

-

-

-

-

The central skull base is a complicated region with many foramina, fissures and canals. Most of these orifices are situated in the inferolateral margin of the greater wing of the sphenoid bone, with the exception of the precavernous carotid canal which resides in the posterolateral margin of the basisphenoid. The anterior wall of the middle cranial fossa is formed by the greater and leser wings of the sphenoid bone. C o n c l u s i o n

The complex anatomy of the central skull base demands high resolution imaging for optimal visualization of lesions within this region. CT has provided respectable results, particularly of the bony structures and soft tissues. MRI has a distinct advantage of being able to clearly delineate the cranial nerves and dural boundaries. MRI can differentiate tumor from other soft tissues such as muscle, fascia, cartilage, fat, fluid and vessels. MRA can substitute for conventional angiography in most cases. These abilities have added new dimensions to imaging,

providing a more detailed evaluation of lesions of the central skull base.

R e f e r e n c e s

Bird CR, Hasso AN, LeBeau DJ (1989) Meningiomas and skull base neoplasms. Top Magn Reson Imag 1:52-68 Creasy JL, Price RR, Presbrey T, Goins D, Partain CL, Kessler RM (1990) Gadolinium-enhanced MR angiography. Radiology 175:280-283 Daniels DL, Haughton VM, Czervionke LF (1988) MR of the skull base. In: Stark DD, Bradley WG Magnetic Resonance Imaging, St. Louis, CV Mosby Co Daniels DL, Czervionke LF, Bonneville JF, Mark LP, Pech P, Hendrix LE, Smith DF, Haughton VM, Williams AL (1988) MR imaging of the cavernous sinus: Value of spin echo and gradient recalled echo images. A JR 151:1009-1014

S 62 Hasso AN, Vignaud J, LaMasters DL (1988) Pathology of the skull base and vault. In: Newton TH, Hasso AN, Dillon WP: Computed Tomography of the Head and Neck. New York, Raven Press Hinshaw DB Jr, Tison JB, Hasso AN, Holshouser B, Thompson JR (1991) MR angiography of head and neck tumors. AJNR (in press) Hirsche WL Jr, Hryshko FG, Sekhar LN, Brunberg J, Kanal E, Latchaw RE, Curtin H (1988) Comparison of MR imaging, CT, and angiogmphy in the evaluation of the enlarged cavernous sinus. A JR 151:1015-1023

Hutchins LG, Harnsberger HR, Dillon WP, Smoker WRK, Osborn AG (1989) The radiologic assessment of trigeminal neuropathy. AJR 153:1275-1282 Laine FJ, Braun IF, Jensen ME, Nadel L, Som PM (1990) Perineural tumor extension through the foramen ovale: Evaluation with MR imaging. Radiology 174:65-71 Parker GD, Harnsberger HR (1991) Clinical-radiologic issues in perineural tumor spread of malignant diseases of the extracranial head and neck. RadioGraphics 11:383-399

Vascular Anatomy of the Skull Base and Treatment of Vascular Lesions P. Lasjaunias, K. terBrugge, I. Iizuka, G. Rodesch, R. Garcia-Monaco Neuradiologie vasculaire, H6pital Bic~tre, Paris, France The skull base vascular malformations represent a topographic entity and not a nosologic one, Their interest is obviously anatomic, clinical and technical in relation to the potential hazards of their management. The dura is a surgical barrier which leaves open some communications that constitute the basis of the symptomatology of the AV shunt of the region: cranial nerves and veins. Therefore the currently named dural AYM is probably a misnomer, there is no AVM of the dura in its congenital and developmental sense. Dural AV shunts regroup different types that have in common the nidus topography, the elements of angioarchitecture, the angiogenetic character that precludes to their development. However, adult and children types are obviously as different as vein of Galen malformation and brain AVM in adults. Multiple classifications are flourishing without either clinical or technical consequences. In practice, the fundamental feature is the presence (or absence) of cortical venous drainage; some unusual dural AV shunts constitute additional varieties that raise nosologic questions: extra-sinusal locations (anterior cranial fossa, tentorium cerebelli... ) and foramen magnum. Their recognition is almost impossible presurgicaUy. In addition subarachnoid venous network draining a dural shunt can be erroneously considered as intradural and wrongly approached after opening of the dura.

focal hemangiomas in infants. Their management is challenging, but can lead to spectacular relief of symptoms and morphological cure. The acquired changes of the dural vasculature and their understanding represents probably the real challenge of these diseases. The search for the link between the meningeal arterial dysplastic changes with or without high flow, and an underlying biological disease, is still continuing. However, we suspect that the endovascular target does not represent the disease to be treated . . . . Extracranial lesions can drain into the cranial cavity and induce vascular changes (infraclinical) of the cerebral veins. They are rare, and not necessarily of a high flow type. Subarachnoid malformations probably exist even if we believe that CNS AVM are subpial. Confusion between draining vein and nidus has led in the past to false appreciation of the size. However subarachnoid AVMs exist in the olfactory and optic nerve areas and cerebello-pontine angle. Finally distinction between a vascular anomaly that can become symptomatic with age (aberrant flow, prominent jugular bulb . . . . ), symptomatic changes of the maturing skull base (benign pulsatile bruit in infants), and true disorders require a solid clinical background, to avoid unnecessary explorations or treatments.

Other types of vascular proliferation can mimick a dural AV shunt: bone hemangiomas, meningeal hemangiomas and multi-

Interventional Neuroradiology of Petrous and Central Skull Base Tumors A. Valavanis Neuroradiology, University Hospital of Zurich, Zurich, Switzerland With the introduction of highly-flexible, flow-independent, steerable microcatheters, new embolic agents and improved technology of detachable microballoons in the past years, interventional neuroradiology assumed a central role in the preoperative management of hypervascular tumors of the petrous bone and central skull base. Two techniques are used either independently or in combination for the management of these lesions:

1) Embolization of the vascular tumor bed through the supplying arteries of the tumor 2) Permanent balloon occlusion of the extradural portion of the internal carotid artery (ICA). Exact topographic evaluation of the lesion by CT/MRI and functional, superselective angiographic investigation are essential prior to planning embolization and/or balloon-occlusion.

S 63 The following tumor types represent major indications for preoperative embolization: Petrous bone • Glomus tumors of the temporal bone • Meningiomas of the petrous bone • Hypervascular neurinomas of the jugular foramen Central Skull Base • Angiofibroma with intracranial extension • Meningioma of the cavernous sinus and petroclival region • H)qgervascular neurinomas.

Modern superselective catheterization techniques not only allow safe and efficient embolization of external carotid feeding branches but also of the cavernous branches of the ICA as well as branches of the ophthalmic and vertebrobasilar system arteries. Postembolization CT/MRI should be routinely" performed in order to assess objectively the degree of tumor devascularization achieved by embolization. Since in the great majority of cases microparticles of PVA are used as embolic agent, with a proven tendency to recanalization, the delay between embolization and operation should not exceed 1 week.

Otoneurosurgery of Petrous Bone Lesions U. Fisch Department of Otorhinolaryngology, University Hospital of Zurich, Zurich, Switzerland The petrous bone can be devided into four compartments: 1. 2. 3. 4.

Tympanomastoid Inframeatal Anteromeatal (apical) and Suprameatal.

The lesions situated in the different compartments are discussed in relation to the approach used for their surgical removal. The temporal bone is also a crucial gateway for reaching lesions of the clivus, infratemporal fossa, pterygo-palatine fossa and cavernous sinus. Appropriate examples wiI1 be given.

Direct Microsurgicai Approach to Tumors and Vascular Lesions of the Cavernous Sinus V.V. Dolenc Department of Neurosurgery, UMC Ljubljana, Yugoslavia Microanatomical studies of the parasellar and sellar regions were conducted bilaterally in 86 fresh cadaver specimens. By using injection techniques for arterial and venous structures a fuller understanding of the cavernoussinus (CS) and sellar region anatomy was made possible. Based upon this new information, direct surgical procedures to remove tumorous and vascular lesions of the CS were carried out. From 1981 through 1990 524 patients were operated on by the author. 412 patients had tumors, and 112 vascular lesions. The most commonly encountered tumors were meningiomas (250 cases), then tumors of the pituitary gland, invading the CS (83 cases), craniopharyngiomas (22 cases), neurinomas (18 cases), chordomas (15 cases), cavernomas (14 cases), and less frequent tumors (10 cases). Of 112 patients with vascular lesions of the cavernous and pericavernous regions, 51 were treated for a caroticoophthalmic aneurysm, 36 for an intracavernous aneurysm, and 25 for a carotico-cavernous fistula.

Overall mortality was 3%. Of the 412 patients operated on for tumors, in 78% of these either total or gross total resection of the tumor was achieved. Exclusion of the vascular lesion was achieved in 100% of the 112 cases. Morbidity immediately after surgery was 80%, mainly due to partial or complete loss of the oculomotor nerve function. Within a year of the operation this was found to be either improved or restored in over 90% of the affected patients. The author addresses in greater detail the following: the reasons for direct surgical treatment of tumorous and vascular lesions of the CS, and the possibilities of preservation or reconstruction of the I C A in vascular and tumorous lesions. The necessity for a team approach in the treatment of patients with tumorous and/or vascular lesions of the central skull base area is required not only in the treatment process but also in the planning, and in the postoperative rehab process as well.

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Scientific Sessions

Scientific Session: Temporal Bone Moderators: B. Appel, Antwerp, Belgium and I.F. Braun, Miami, USA 08.30 a m - 08.45 am

Keynote Address: Cholesteatoma: CT correlation and MRI-findings B. Appel, Antwerp, Belgium

08.45 a m - t0.30 am

Scientific Papers 21 - 31

10.30 a m - 11.00 am

Coffee Break

08.45 am-lO.30 am Scientific Papers 21-31 021 Anatomic variations of the cochlea C. Muren, P. Dimopoulos, Stockholm/Uppsala, Sweden 022 The carotid canal and the cochlea

K. Wadin, C. Muren, H. E Wilbrand, Uppsala/Stockholm, Sweden 023 CT of the stapediai footplate E Veillon, 13. Nguyen, M. Bintner, P. Meriot, P. Bourjat, Strasbourg, France 024 Radioanatomy of the singular nerve canal C. Muren, K. Wadin, P. Dimopoulos, Stockholm/Uppsala, Sweden

027 Isolated malformations of the internal auditory meatus C.R. Guirado, Barcelona, Spain 028 Pathology of the membranous labyrinth, CT and MR imaging J.W. Casselman, R. Kuhweide, W. Ampe, Brugge, Belgium 029 The vestibular aqueduct in computed tomography; A comparative radioanatomic study P. Dimopoulos, H. E Wilbrand, Uppsala, Sweden 030 CT Imaging of otosclerosis

G.C. Ettore, A.P. Garribba, Bari, Italy 031 CT of the petrous bone in achondroplasia

025 Imaging facial nerve neuromas P.D. Phelps, G.A. Lloyd, London, United Kingdom 026 Gd-DTPA-enhanced MR imaging in petrons bone involvement: meningeal findings N. Martin, Oo Sterkers, G. Lamas, H. Nahum, Paris, France

C.R. Guirado, R. Roig, G. Morello, Barcelona, Spain

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Keynote address CHOLESTEATOMA:CORRELATION OF CT AND MRI FINDINGS B.Appel (i), W.Verstraete (2) Department of Neuroradiology (i) and ~ T (2), A.Z. Middelheim, Antwerp, Belgium Since many years, the diagnosis of a petrous cholesteatoma can easily be made by computed tomography (CT) by means of visualisation of pathological soft tissue and associated bone erosions. But differential diagnosis remains sometimes difficult with cholesterol granuloma, brain herniation, etc.. More difficult however is the interpretation of CT findings after surgery, looking for relapsing cholesteatoma. At that time the parameter of bone erosion is not very helpfull and the interpretation of the soft tissues by means of configuration is not able to differentiate granulema, scar tissue or cholesteatoma relapse. Different authors have assessed the possibility of soft tissue differentiation in petrous pathology using magnetic resonance imaging (MRI). With thin slices, TI, protondensity and T2 weighted technique, eventually associated with the injection of Gadolinium, differential diagnosis can be approached. Using our own material, we will illustrate this topic and discuss the specificity of the findings compared to surgical results and histopathological diagnosis.

21 ANATOMIC VARIATIONS OF THE COCHLEA C. Muren and P. Dimopoulos Dept.s of Diagnostic Radiology,

and University ttospital, Uppsala, Sweden

A thorough knowledge of the normal range of variation of anatomy and topography of the cochlea is necessary for optimal reproduction of this structure and Radiographic

correct interpretation

identification

of the radiographs.

of incomplete cochlear coils is essential

in tile diagnosis of congenital malformations such as Mondini's deformity. Furthermore, a diagnosis of otosclerosis/otospongiosis has to be based on recognition of changes in the otic capsule. Tile size and shape of the human cochlea and the normal ranges of variation of its dimensions were evaluated

in 95 plastic casts,

prepared

from temporal bone specimens. Tile

variation

is

digression

fairly

from

small,

this

symptoms, indicates

22

Sabbatsbergs Hospital, Stockhohn,

and

range,

is

not

associated

normal range of

age-dependent. with

pertinent

Obvious clinical

an abnormality.

23

THE CAROTID CANAL AND THE

COCHLEA

K. Wadin, C. Muren, H.F. Wilbrand. Dept. of Diagn.Radiol.Univ.Hosp.of Uppsala and Sabbatsberg Hospital, Stockholm, S W E D E N .

The carotid canal lies in close topographic relationship to the basal turn of the cochlea. T h e b o n y wall b e t w e e n t h e m consists in s o m e cases only of the petrous bone of the otic capsule. It can be as thin as 0.2 m m . In other cases the distance can be m o r e than 6 ram. A systematic assessment of the relationship between these two structures w a s performed on plastic casts of 173 human temporal bone specimen in order to investigate the range of normal variations. T h e topography in this region can easily be visualized by CT.

C.T. OF THE STAPEDIAL FOOTPLATE F. VEILLON, D. NGUYEN, M. BINTNER, P. MERIOT, P. BOURJAT CHU - STRASBOURG Purpose : The purpose of t h i s work is to evaluate the information provided by C.T. in the study of the anatomy and pathology of the stapedial/footplate. Materials and Methods : Various affections of the stape~ial f o o t p l a t e are studied using axial I mm C.T. sections, with an 0.5 mm increment, p a r a l l e l to the orbito-meatal plane. Otosclerosis (n : 27), traumatisms (n : 3), malformations (n = 2) with aplasia or hypoplasia of the f o o t p l a t e , and tympanosclerosis (n = 2). A reference population of 40 patients was studied using the same c r i t e r i a . A l l the C.T. results (except f o r the malformations) were confronted with the surgical f i n d i n g s . Results : In otosclerosis (n = 27), C.T. shows a thickened f o o t p l a t e in 12 cases, thinned in 15 cases with one f a l s e negative and no false p o s i t i v e ( s e n s i t i v i t y = 92 %, s p e c i f i ~ - t y = 100 %). In traumatisms, C.T. demonstrates a i r in the v e s t i b u l e , a f o o t p l a t e f r a c t u r e in 2 cases, a stapedo-vestibular dislocation in I case, confirmed by surgery. Aplasia or hypoplasia of the stapes in p e r f e c t l y evaluated by axial and coronal sections. The study of the reference population shows a smooth f o o t p l a t e , less than I mm t h i c k , v i s i b l e on at least 2 sections. Conclusion : C.T. gives excellent r e s u l t s in the evaluation of the stapedi al footplate, demonstrating the improvement of spatial resolution in moderns scanners.

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25

24 RADIOANA'IOMY OF THE SINGULARNERVE CANAL C. Muren, K. Wadin and P. Dimepoulos Dept.s of Diagnostic Radiology, Sabbatsbergs Hospimf, Stockhohn, and University Hospital, Uppsala, Sweden The singular canal conveys vestibular nerve fibers from the ampulla of the posterior semicircular canal to the internal acoustic meatus at its postero-inferior aspect. The radiographic identification of this anatomic structure will help to distinguish it from a fracture. It is also a landmark in certain otosurgic procedures. With respect to the appearance of the singular canal, computed tomography (CT) examinations of I0 deep-frozen temporal bone specimens were compared with the subsequently prepared plastic casts of these bones, showing good correlation between the true anatomy and the images. The singular canal and its varying anatomy were evaluated in CT examinations ef the temporal bones of 107 patients. The singular canal could be identified, beth in the axial transverse and in the coronal views. Its point of entry into the internal acoustic meatus varied considerably.

IMAGING FACIAL NI~RVE NEI/ROMAS P.D.Phelps, G.A. Lloyd Royal National Throat, Nose and Ear Hospital, London, U.K. Neuromas w~lich arise from the seventh cranial nerve are rarer than those arising from the eighth nerve, but nevertheless a significant incidence has been shown by temporal bone studies from asyr~mtoalatic patients. The tumours can arise from any part of the intrat6m~poral course of the facial nerve and the resulting variable syaE0tcmatology causes diagnostic problea~. We have reviewed thirteen patients with facial nerve neuroma investigated over a period of thirteen years, as well as one case of an haemangic~a arising from the facial nerve in the teniooral bone. The imaging regime has altered progressively over this time. Deafness was a more cc~non presenting symptom than facial palsy and in two patients presentation was as a mass in the parotid region. Imaging was by pluridirectional tomography, CT and MRI with Gadolini~n enhancement. Four patients had widening of the internal auditory meatus and five enlargement of the descending part of the facial canal, shown on the bone studies. A notch in the antero-superior ~ r t m e n t of the IAM suggested a facial rather than an acoustic neuroma in two patients. CT showed a soft tissue mass in the ~ d d l e ear in five patients and combined air meatogram a mass in the cerebello-pontine angle in two. We conclude that a regime of high resolution CT in axial end coronal planes with reformatting in the sagittal plane, followed by MR and C ~ should demonstrate all facial nerve neuromas and identify accurately the situation and extent of these tumours.

27

26 Gd-DTPA-enhanced MR Imaging in petrous bone involvement : meningeal findings. N. MARTIN, O. ST~RKERS, G. L&~IAS, H. IiAHI}4 Neuroradiology Dept., G.H. Piti6-Salp6tri~re, PARIS To evaluate meningeal involvement occuring in petrous bone pathology (excluding acoustic neuroma or pontecerebellar lesions), the authors reviewed a series of 66 patients with petrous lesions, examined with CT and GdDTPA-enhanced MRI. 12 patients displayed an abnormal dural enhancement : inflammatory lesions 7, malignant tumors 4, agressive meningioma 1. A retrospective analysis evaluates the significance of these patterns which are correlated with the clinical evaluations and surgical findings. Gd-DTPA-enhanced MRI optimally evaluated dural involvement with an exclusively MR detection in 6 cases. In the 7 cases with inflammatory lesions (cholesteatomas 4, postoperative 2 tuberculosis l) dural enhancement was correlated wlth a surglcally thickened dura and granulation tissue (5), an easily lacerated dura (1) or with pus against the dura (1). In 4 of these 7 cases, follow-up MR studies had a high correlation with clinical evohtion (favourable 3, unchanged 1)~whereas evolution of bony involvement (as apicitis) was accurately demonstrated. In 3 of the 4 cases with malignant tumors, surgical approach showed an infiltrated dura (I), a tumoral adherence with the dura (1) or its seropuralent infiltration (I). So, the accurate MR demonstration of abnormal dural enhancement appears quite informative in planning surgical or therapeutic approaches in petrous bone pathology. •

,

.

}

ISOLATED MALFORMATIONS O F THE INTERNAL AUDITORY MEATUS C. R. Guirado Instituto de Tomodensitometrfa, Barcelona, Spain Malformations of the internal auditory meatus may or m a y not be associated with other development anomalies, but those affecting only the internal auditory meatus are very infrequent. Narrowing is the most common anomaly; it can affect the porus or the entire internal auditory canal. A g e n e s i a of the internal auditory m e a t u s is also found. Solitary unilateral m a l f o r m a t i o n s of the i n t e r n a l auditory meatus can produce symptoms resembling those o f an a c o u s t i c n e u r o m a . P a t i e n t s w i t h u n i l a t e r a l neurosensory hearing loss are often referred initially for a magnetic resonance examination in expectation o f the diagnosis of a tumour. However, C T can recognise b o n e anomalies, a possibility which might otherwise be neglected. We found that isolated malformations of the entire internal auditory canal were the most infrequent of all.

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28 PATHOLOGY OF THE MEMBRANOUS LABYRINTH, CT AND MR IMAGING J.W.Casseiman*, R.Kuhweide**, W. AMPE** Department of Radiology* and 0torhinolaryngology** A.Z. St. Jan Brugge, Belgium The aim of the study was to evaluate the diagnostic value of CT and MR in patients with pathology of the membranous labyrinth. We also tried to find out whether classic 2-3mm thick spin-echo images (without and with Gadolinium administration) or imm thin 3D-CISS-images were necessary to make the diagnosis. In five patients, presenting with sensorineural hearing loss, tumoral or inflammatory pathology was found in the labyrinth (schwannoma, viral labyrinthitis, metastasis, epidermoidoma, fibrous dysplasia). Lesion in the internal auditory canal and along the facial nerve were excluded from the study. All patients underwent a high resolution CT and a MR study (TI,T2 and Gd enhanced T1 images were performed in all patients, a 3D-CISS study was performed in three patients). CT led to the diagnosis in only one patient. Routine spin-echo images led to the correct diagnosis in all patients although the use of Gadolinium was necessary in two patients. The 3D-CISS sequence was less sensitive, in one of the three patients the pathology was not seen on the 3D images. MR surpasses CT in the diagnosis of membranous labyrinth pathology although CT remains necessary to exclude other causes of sensorineural hearing loss and vertigo. Gd enhanced Tl-weighted images were able to detect pathology in all patients but unenhaneed images were also necessary to exclude the presence of proteinaceous fluid or blood in the labyrinth. 3D images are less sensitive but can sometimes add morphologic information (thinner slices).

30 CT IMAGING OF OTOSCLEROSIS. G.C.ETTORRE, A.P.GARRIBBA ISTITUTO DI RADIOLOGIA DELL'UNIVERSITA' DI BARI - ITALY Otosclerosis is a hereditary dystrophy of the otic capsule, affecting more often female than male. It is characterized by bone structure modifications, related to the presence of otospongiotic foci. The development of otospongiotic foci consists of two phases: the first one is an osteolytic or active phase ("immature phase"), the s! cond one is an oateosclerotic or inactive phase ("mature phase"). Otosclerotic lesions may originate in almost any region of the labyrintine capsule. In most cases, the pathologic process develops in a so-ca~ led "area of predilection" (fissula ante fenestram). Clini cally we can distinguish a fenestral otosclerosis, charact£ rized by progressive conductive hearing loss and a cochlear otosclerosis, characterized by sensorineural hearing loss. The demonstration of the otosclerosis lesions is exclusiv~ ly radiologieal: CT is the best imaging method to detect them. In the last five years, on 185 patients with suspected otosclerosis, 62 cases of otospongiosis have been diagnosed by high resolution CT. The Authors believe that,while cochlear otosclerosis diagno sis is possible in the sclerotic phase,fenestral otosclerosis diagnosis can be a l ~ s made after the 3th disease stage.

29 THE VESTIBULAR AQUEDUCT IN COMPUTED TOt'IOGRAPHY A comparative radioanatom ic study P.A. Dimopoulee & H.F. Wilbrand, Uppsala Univ. Inst Diogn.Radiology The proper identificationof both the cochlear and the vestibular aqueducts in CT asks for a corresponding knowledge of the course of

the aqueductsand their varying gross morphology. The radioanatomy of the cochlear aqueduct has extensively been displayed in recent studies by members of the Uppsala group. Corresponding but not sufficiently extensive comparative radioanatomic investigations of the vestibular aqueduct have been done. Siebenmann and Anson et coll. have displayed the gross anatomy but have not been suffieienly observed by radiologists. This might have been the reason for a series of sometimes contradictional points of view in publications with clinicalconnection. Iffuture magnetic resonans evaluation will possibly shed more light on the normal end pathomorphology and -physiology of the endolymphatic duct and sac in the vestibular aqueduct, knowledge of the varying redioanatom7 of the aqueduct will be helpful. For an extensive statistical evaluation fresh, frozen temporal bones were examined by CT in the conventional AP and Axial views. Plastic casts of these specimens were prepared for measurements and for the evaluationof their gross morphology. The results display considerable gross anatomical variations in form, length and volume of the aqueduct and its course through the pyramid. T h e / m a y serve as a guidance for e better understanding of the gross morphology of the pyramid and for future investigations.

31 CT OF THE PETROUS BONE IN ACHONDROPLASIA C. R. Guirado, R. Roig, G. Morello Instituto de Tomodensitometria, Barcelona, Spain We reviewed the skull base with CT in 35 achondroplastic subjects, most of them presenting hearing loss. A hypoplastic mastoid and narrowing of the skull base was seen in all the cases. An abnormal rotation of the petrous pyramid was also visible. Otitis media Was not infrequent. We found no case of inner or middle ear malformation (including the ossicular chain) in our series. Upward tilting of the internal auditory canal was always present. No evidence of basiliar invagination was detected, in spite of the tilting of the petrous ridges.

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Scientific Session: Head and Neck Tumors Moderators: K. Reisner, Karlsruhe, Germany and K.A. Shaffer, Milwaukee, USA

11.00 a m - 11.15 am

Keynote Address." Influence of CT on Radiooncological Treatment Planning in Tumors of the Skull K. Reisner, Karlsruhe, Germany

11.15 a m - 12.30 pm

Scientific Papers 3 2 - 42

12.30 pm-02.00 pm

Lunch - Seminar

11.15 am-12.30 pm Scientific Papers 32-42 032 MR imaging of the oro- and hypopharynx tumors: evaluation of the response to the treatment M. De Santis, R. Romagnoli, A. Casolo, D. De Maria, A.M. Falchi, P. Torricelli, Modena, Italy

037 CT presentation of head and neck lymphomas J.E Lirng, M.H. Teng, S.S. Chen, T. Chang, Taipei, Taiwan, Rep. of China 038 MRI of adenolymphomas of the parotid gland

033 Evaluation of MR imaging for tumor extent and differential diagnosis of nasopharyngeal carcinomas R. Nishimura, M. Takahashi, H. Uozumi, T. Sawada, Y. Sakamoto, M. Sumi, Kumamoto, Japan 034 Value of contrast enhanced CT in recurrent malignancy of the head and neck region B. Kersting-Sommerhoff, M. Lenz, W. Bautz, W. Riffeser, Munich, Germany 035 Contrast enhanced computed tomography in pretherapeutic T-staging of orofaciai tumors B. Kersting-Sommerhoff, M. Lenz, S. Kretz, M. Strotzer, Munich, Germany 036 The frequency of osteosclerosis of the skull base in nasopharyngeal carcinoma S. Tada, M. Ariizumi, M. Ida, T. Tatsuno, K. Fukuda, Tokyo, Japan

N. Freling, Groningen, Netherlands 039 MRI of pleomorphic adenomas of the parotid gland N. Freling, Groningen, Netherlands 040 MRI, ultrasound, and surgical correlation of orbital tumors K.L. Gupta, A.M. Righi, E Mihara, A.E. Robinson, B.G. Hail<, New Orleans, USA 041 MRI, ultrasound, and ophthalmoscopic evaluation of ehoroidal melanoma K. L Gupta, A.M. Righi, E Mihara, A.E. Robinson, B.G. Haik, New Orleans, USA 042 MR imaging in post-thyroidectomy patients: clinical correlation R.A. Holliday, P.M. Martin, M. Blum, L.W. Greene, V. Peck, J.W. Weinreb, New York, USA

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Keynote address mUENCE OF CT ON ~ O O N C ~

32 TP~_AT~NTP L ~ N ~

IN T U ~ OFlie SKULL. K. R. Reisner, R, Kirchr~, Radiologische Klinik, St. Vincentius~itals, Karlsruhe, Germany. CT offers many~nd various informations about tumors of facial skull and skull base. Thereis the cpestion, however to what extent these informations m~ehelpful: tumor-diagnosis is usually madebeforeCT by clinical and histological exa~inatien; treaim~ntplanning follows certain, r~ther fixed rules depending on type and location of tumor and considering in particular the well knc~q pathwaysof ly~hnode involv(m~nt. I t seemsjustified, thereforeto do retrospective studies comparing radiological needsand questions with the answers of CT. Weevaluated our in the sameinstitution diagnosed and treated tunqr patients this way and present data and cases de~0nstrating the retrospectivelydetermined efficiency oF CT.

33 EVALUATION OF MR IMAGING FOR TUMOR EXTENT AND DIFFERENTIAL DIAGNOSIS OF N A S O P H A R Y N GEAL C A R C I N O M A S Nishimura R, Takahashi M, Uozumi H, Sawada T, Sakamoto Y, Sumi M Department of Radiology , Kumamoto University School of Medicine Tumor extent and differential diagnosis of nasopharyngeaI tumors were evaluated on the basis of 32 patients with various neoplasms of the nasopharynx. The histologic diagnoses included 11 nasopharyngeat carcinomas, 3 malignant lymphomas, 3 angiofibromas, 3 chondrosarcomas and 12 miscellaneous conditions. Nasophryngeal carcinomas were divided into 4 stages on MR findings, depending upon the tumor extent. In stage 1, only thickening of the mucosa was observed as a less enhancing area in the normally enhancing mucosa with Gd-DTPA. In stages 2 and 3, pharyngobasilar fascia was involved and the tumor border was demonstrated well. Cavernous sinus extension in stage 4 was demonstrated as a parasellar tumor. Histologic diagnosis of angiofibroma was often possible by early enhancement and signal voids within the tumor. Considerablly high signal intensity was noted for rhabdomyosarcoma and malignant lymphoma, whereas chondrosarcoma showed mixed high and low signal intensities. In conclusion, MR imaging was useful for the diagnosis of tumor extent and differential diagnosis of nasopharyngeal carcinoma.

MR IMAGING OF THE ORO AND HYPOPHARINX TUMORS:EVALUATION OF THE RESPONSE TO THE TREATMENT. M. De Santis,R. Romagnoli,A. Casolo,D. De Maria,A.M. Falchi~P.Terricelli. Institute of Radiology and Department of Radiation Therapy,University of Modena. Twelve patients with oro and hypopharinx carcinomas were examined.MR images were obtained with a 1.5 T superconducting system,using Tl-weighted,proton-density-weighted and T2-weighted spin-echo sequences.All patients were reexamined after injection of Gd-DTPA in a dose of 0.2 ml/ per Kg. The patients underwent to 3 cycles of chemotherapy with CDDP and 5 FU as the AI Sarraf plan;then received radiation therapy(60-65 Gy)on the tumor.They were re-examined following chemoteraphy and 30 days after radiation theraphy,for evaluating the efficacious of the treatment. The studies were graded from O to 3.Grade 0 was defined no respond to the treatment.Grade i meant residual tumor >50% and grade 2 residual tumor<50%.The patients who showed full response after theraphy were defined as grade 3. Moreover the value of different pulse sequences was compared. Results. All patients showed grade 2 after chemoteraphy.Ten patients rose to grade 3 after radiation theraphy,whereas MR image proved residual tumor in 2 patients.T2-weighted image and Gd-DTPA image in particular, were the best in the evaluation of the efficacious of the treatment.Our experience is still too limited.Initial resuits show high accuracy of MR imaging in the evaluation of the response of the oro and hypopharinx carcinomas to combined chemo and radiation theraphy,

34 VALUE OF CONTRAST ENHANCEDCT IN RECURRENT MALIGNANCY OF THE HEADAND NECKREGION B.Kersting-Sommerhoff; M.Lenz; W.Bautz; W,Riffeser; Dept. of Radiology, Technical University Munich, Germany

Puroose: 544 CT examinations in 231 patients (115 recurrent tumors, 76 recurrent lymph node metastases) were analyzed retrospectively to assess the role o f contrast enhanced CT in the posttherapeutic monitoring of patients with head and neck neoplasms in comparison and as a supplement to c l i n i c a l examination. Method: CT scans were obtained with a scan time of I-3 sec and 4-5 mm s l i c e thickness in contiguous scanning. Contrast media were applied as a 50 ml bolus injection followed by 100 ml f a s t infusion (300 mg Iodine/ml). Recurrent malignancies were identified using the c r i t e r i a mass lesion, hyperdensity, enhancement and structural characteristics (inhomogeneity e c t . ) . Results: CT (80%) was i n f e r i o r to c l i n i c a l examination (87%) in the detection of recurrent malignancy, but superior in depicting the extent of larger lesions. CT (95%) was superior to c l i n i c a l examination (80%) in the detection of recurrent lymph node metastases. Conclusion: Contrast enhanced CT is especially suitable f o r detection of recurrent lymph node metastases. CT supplements the c l i n i c a l examination in the dection of recurrent malignancy by depicting the extent of the lesion. A base line CT examination is of great importance.

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CONTRAST ENHANCED COMPUTEDTOMOGRAPHY IN PRETHERAPEUTIC T-STAGING OF OROFACIALTUMORS. B.Kersting-Sommerheff; M.Lenz; S.Kretz; M.Strotzer Dept. of Radiolo9Y, Technical University Munich, Germany

THE FREQUENCY OF OSTEOSCLEROSIS OF THE SKULL BASE IN NASOPHARYNGEAL CARCINOMA

Purpose: CT examinations of 174 patients with tumors of the oral cavity (28), floor of the mouth (79) and the oropharynx (67) were analyzed retrospectively to assess the role of contrast enhanced CT in the pretherapeutic t staging in comparison and supplemental to clinical evaluation. Method: CT scans were obtained with a scan time of I-3 sec and 4-5 mm slice thickness in contiguous scanning. Contrast media were applied as a 50 ml bolus injection followed by 100 ml fast infusion (300 mg Iodine/ml). Malignancies were identified using the c r i t e r i a mass lesion, hyperdensity, enhancement and structural c r i t e r i a (inhomogeneity etc). Size, demarcation, expansion, i n f i l t r a t i o n of landmark structures and bone destruction were defined for each lesion. Results: CT (53%) was inferior to clinical evaluation (90%) in the t-staging of small and superficially located tumors. CT evaluation of masses of the oral cavity were specifically impaired by a r t i f a c t s due to dental fillings. CT (91%) was superior to clinical evaluation (34%) in the t-staging of larger masses and reliably demonstrated bone destruction and tumor i n f i l t r a t i o n into deeper compartments. A combination of clinical and CT findings in.t-staging resulted in a sensitivity of 90Z at a specificity of 97%. Conclusion: Contrast enhanced CT in combination with clinical evaluation is a reliable b a s i s for therapy planning, prognostic outlook and clinical-therapeutic studies.

S. Tada, M. Ariizumi, M. Ida, T. Tatsuno, K. Fukuda Department of Radiology, The Jikei University School of Medicine Sclerosis of the base of the skull as a manifestation of nasopharyngeal carcinoma has long been noticed, but the true incidence of it has yet to be known. We performed thin-slice, high resolution CT to determine the incidence and the pathogenesis of osteosclerosis of the skull base in nasopharyngeal carcinoma. 35 cases with nasopharyngeal carcinoma was studied before the treatment with special attention to the bony detail of the skull base. In the present series nearly half of the cases the base of the skull was involved and 35% of the cases showed osteosclerosis somewhere at the skull base. 11 of 12 cases(92%) and 28 of 44 sites(64%) with osteosclerosis were coexistent with osteolytic destruction. Tumor extension was closely related to the skull base involvement. Extension of the tumor into the pterygopalatine fossa was always associated with osteosclerosis of the sphenoid body, often with enlargement of the vidian canal. The skull base involvement was frequently encountered in the extrapharyngeal extension of the tumor. We believe that osteosclerosis of the base of the skull indicates direct tumor invasion, and that, thus, it is clinically important to investigate the bony detail of the skull base by CT in the nasopharyngeal carcinoma.

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CT PRESENTATIONOF HEAD AND NECK LYMPHOMAS J.F. Lirng, M.H. Teng, S.S. Chen, T. Chang Department of Radiology, Veterans General Hospital-Taipei Section of Radiology, National Yang-Ming Medical College

MRI OF A D E N O L Y M P H O M A S O F T H E

We collected 50 cases of head and neck lymphomas, including 39 men and i i women in the range between 6 and 84 years of age. The most common symptom is neck mass(as), found in 56% of our cases. Intranodal lesions were found in 22% of oases; extranodal i n t r a lymphatic lesions in 42%; extranodal extralymphatic lesions in 30% and multifocal extranodal lesions in 6%. A combination of extranodal and nodal disease is the p r e v a i l i n g CT presentation in our study, followed by the lesion type of extranodal involvement alone. The CT presentation of s l i g h t l y hypodense or isodense soft tissue mass lesions with or without rim enhancement was found in 82% of our cases. Focal low attenuation areas within the lesion were found in 18%. Lymphomas of the scalp and tongue and Hodgkin's disease in the parotid gland were also noted in our series. CT examination plays an important r o l e in suggesting diagnosis, treatment planning and evaluation for recurrence following treatment of head and neck l ymphomas.

PAROTID

GLAND

We studied 146 patients w i t h MRI for the e v a l u a t i o n of a c l i n i c a l l y suspect mass lesion in the p a r o t i d space. A t a 1.5T s y s t e m spin echo T1 and T2 w e i g h t e d images (WI) were acquired, u s i n g a h e a d coil. Histology was obtained in all patients. A d e n o l y m p h o m a s are b e n i g n tumors, which m a y cause an i n f l a m m a t o r y r e a c t i o n in adjacent tissues mimicking malignant infiltration. Unless pleomorphic adenomas they may be m u l t i p l e and bilateral. We a s s e s s e d MRi c h a r a c t e r i s t i c s of a d e n o l y m p h o m a s analyzing tumor localization, tumor margins, infiltration and signal intensity (SI) on T1 and T2 WI, to d i f f e r e n t i a t e them from other p a r o t i d tumors. 19 of 24 a d e n o l y m p h o m a s w e r e localized in the superficial part of the gland. In 5 patients the tumor was in the superficial as well as in the deep part. There were 16 solitary lesions, 8 were multiple. 3 patients had b i l a t e r a l and m u l t i p l e lesions. Tumor margins w e r e sharp in 13 of 24 patients and u n s h a r p in II. 3 patients showed i n f i l t r a t i o n into the subcutaneous fat. Tumors were inhomogeneous in 17 of 24 patients. SI was evaluated for T1 and T2 WI. A p r e d o m i n a n t l y low SI was noted for T1 as well as T2 WI c o m p a r e d tO other p a r o t i d tumors. TIT2 calculations r e v e a l e d a lower value for TI and T2 of adenolymphomas w h i c h significantly d i f f e r e d from other p a r o t i d tumors. MRI correctly identified 22 of 24 patients w i t h adenolymphoma. However, w h e n MRI diagnosed a tumor as adenolymphoma only 22 of 35 were correctly predicted. Sensitivity is 91%, specificity 86%, "positive predictive value 62% and n e g a t i v e predictive value 97%.

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MRI OF PLEOMORPHIC ADENOMAS O F T H E PAROTID GLAND

MRI, ULTRASOUND, AND SURGICAL CORRELATIONOF ORBITAL TUMORS K. L. Gupta, A. M. Righi, F. Mihara, A. E. Robinson, B.G. Haik

We examined 46 patients with a pleomorphic adenoma of the parotid gland using a 1.5T system. Spin echo T1 and T2 w e i g h t e d images (WI) were performed with a head coil. Histology was obtained in all patients. Pleomorphic adenomas all had sharply defined tumor margins, which were smooth in 12 of 46 and lobulated in 34 patients. All tumors were homogeneous on T1 WI. On T2 WI 30 tumors showed a homogeneous and 16 tumors an inhomogeneous aspect. Signal intensity (SI) , expressed in relation to normal parotid tissue, was low on T1 WI for all tumors. T2 WI demonstrated predominantly very high SI (+++) in 32/46, [++) in 7/46, (+) in 3 and low (-) in 3 of 46 patients. T1 and T2 values for pleomorphic adenomas are significantly elevated compared to other benign and malignant parotid tumors. In the literature low SI is thought to represent highly cellular tissue (Som, 1989). With a semiquantitative histological score we tested our hypothesis, that the typically very high SI in pleomorphic adenoma was due to the presence of large amounts of m y x o i d substance within the tumor. Although low SI correlated with large fields of cellular tissue and high SI with the presence of myxoid substance, no significant correlation was demonstrated. Sensitivity of MRI for pleomorphic adenomas was 87%, specificity 91%, positive predictive value 87% and negative predictive value 91%. Pleomorphic adenomas may resemble simple cysts, lymph nodes or dilated salivary ducts. Rarely a malignant tumor mimicks a pleomorphic adenoma.

Purpose: To compare MR and ultrasound imaging of orbital tumors. Heth~s: Eighty-two orbital mass lesions were examined with MR imaging and ultrasound. Fortytwo had surgical correlation. Results: MR has better soft tissue contrast, which f a c i l i t a t e d specific diagnoses of hemorrhage, melanoma, and retinoblastoms. This was enhanced by the use of contrast material and additional gradient-echo pulse sequences. Ultrasonography was more sensitive to small lesions of 2 mm or less. One melanoma, two retinoblastomas, and accompanied subretinal f l u i d collection were only detected by ultrasonography. However, deeper portions of the retrobulbar area and intracranial involvement were better evaluated by MRI. Conclusion: MR imaging and ultrasonography are complementary in evaluating orbital tumors.

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MRI, ULTRASOUND, AND OPHTHALMOSCOPIC EVALUATION OF CHOROIDAL MELANOMA K.L. Gupta, A.M. R i g h i , F. Mihara, A.E. Robinson, B.G. Haik

MR IMAGINGIN POST-THYROIDECTOMYPATENTS: CLINICALCORRELATION HoUiday RA, Martin PM, Blum M, Greene LW, Peck V, Weinreb JW Departments of Radiology and Medicine New York University Medical Center New York, New York USA

Purpose: To compare the MR and u l t r a s o u n d imaging in choroidal melanoma. Methods; F o r t y - t w o choroidal melanomas g r e a t e r th~n 2 mm in diameter were examined w i t h MR imaging, u l t r a s o u n d , and ophthalmoscopy. Twentyseven had contrast-enhanced MRI. MR imaging and u l t r a s o n o g r a p h y were compared. Results: Tumor s i z e c o r r e l a t e d well between MRI and u l t r a s o n o g r a p h y ( c o e f f i c i e n t o f c o r r e l a t i o n = 0.83 f o r p r e c o n t r a s t imaging and u l t r a sonography, and 0.92 f o r p o s t c o n t r a s t imaging and ultrasonography). A l l the tumors were detected by u l t r a s o n o g r a p h y ; however, one small melanoma was not e v i d e n t on MRI. Three associated s u b r e t i n a l f l u i d c o l l e c t i o n s were not c l e a r l y i d e n t i f i e d on MRI. Ultrasonography provided n o n s p e r i f i c imaging; however, signal c h a r a c t e r i s t i c s and c o n t r a s t enhancement o f melanoma on MRI provided r e l i a b l e diagnoses. Conc|us~on: MR imaging and ultrasonography are

complementary in evaluating uveal melanoma.

MR neck examinations and clinical records of 46 patients status post thyroidectomy for papillary or follicular thyroid carcinoma were reviewed. 61 scans were performed at t.5 T utilizing a head coil with shoulder cut-outs. 3 examinations were performed at 0.5 T. Sagittal SE 700/20, axial SE 700/20 and axial SE 1800-2300/30, 80 pulse sequences were utilized. Images were prospectively evaluated for evidence of local or nodal tumor recurrence. Images were retrospectively compared with the results of physical examination, total body 1311 imaging and serum thyroglobulin assay. All cases of suspe~ed recurrence were confirmed pathologically. MR correctly predicted local tumor recurrence in four patients. MR correctly predicted metastases in nodes >_ 1.5 cm in diameter in ten patients. No characteristic signal pattern was identified in the nodal metastases. Nodal metastases failed to accumulate 1311 in four cases. Serum thyroglobutin levels were elevated in tweive patients. MR excluded recurrent disease in six patients with palpable neck masses, including three patients with asymmetric sternohyoid muscles secondary to surgical sacrifice of the inferior root of the ansa cervicalis. MR imaging is a valuable adjunct to the traditional methods of monitoring patients with papillary or follicular thyroid carcinoma. Indications for MR imaging include (t) Palpable neck mass (2) Elevation of serum thyroglobulin levels (3) Suspected non-functioning metastases (4) Localization of neoplasm identifed on 1311 imaging prior to surgical or ablative therapy.

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Scientific Session: Larynx and Upper Neck Moderators: A. Hemingsson, Uppsala, Sweden and H.D. Curtin, Pittsburgh, USA

02.00 p m - 02.15 pm

Keynote Address: Larynx Imaging H.D. Curtin, Pittsburgh, USA

02.15 pro-03.30 pm

Scientific Papers 43-52

03.30 pm-04.00 pm

Coffee Break

02.15 pm-03.30 pm Scientific Papers 43-52 043 Contrast enhanced computed tomography in pretherapeutic T-staging of larynx and hypopharynx tumors M. Lenz, B. Kersting-Sommerhoff, W. Bautz, M. Strotzer, Munich, Germany 044 MRI in the staging of laryngeal carcinoma E Campodonico, C. Della Rocca, A. Vidiri, A. Greco, M. Santarelli, R. Guerrisi, Roma, Italy 045 Sjoegren's disease of the parotid gland - correlation of MR imaging, clinical and pathological findings T. Vogl, S. Dresel, M. Spaeth, G. Grevers, J. Lissner, Munich, Germany

048 Unusual causes of epistaxis B. Azar-Kia, S. Horowitz, M. Fine, J. Delgado, Maywood, USA 049 Comparative clinical and radiological study of trauma of the skull base R. Roig, C.R. Guirado, G. Garcia, Barcelona, Spain 050 Ultra-fast MRI of the upper airway during active respiration: Application for evaluation of obstructive sleep apnea C.J. Schatz, E G. Shellock, P. Julien, T. K. E Foo, Los Angeles, USA 051 Impact of tongue hypertrophy in apneic patients

046 Gadolinium-enhancement in craniofacial fibrous dysplasia J.W. Casselman, J. Vanvuchelen, L. Neyt, G. D'Hont, Brugge, Belgium

K. Marsot-Dupuch, E Chabollc, X. Lashiver, A. 1". Iyriboz, Paris, France 052 Obstructive sleep apnea syndrome: Cephalometric findings

047 Postsurgical MRI evaluation of patients treated with combined cranio-faciai resection R. Musumeci, L. Balzarini, G. Cantfl, E. Ceglia, M.I. Grosso, E Mattavelli, R. Petrillo, Y. Reiner, C.L. Solero, L D. Tesoro Tess, Milano, Italy

M. de la Fuente, L. Dominguez, J. Campollo, A. Ramos, J. Ferrando, Madrid, Spain

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Keynote Address:

Larynx Imaging H.D. Curtin Department of Radiology, Eye and Ear Hospital, Pittsburgh, Pennsylvania, USA Imaging of the larynx is not done to detect tumors but rather to show the limits of extension. In many cases the imaging is aimed at determining whether or not a patient is a candidate for a partial laryngectomy. Certain landmarks, such as the ventricle and the cricoid cartilage become extremely important in making such determinations. Either CT or MRI can be used to assess tumors of the larynx. In our opinion, MRI has certain advantages over CT but is more difficult to perform and often more expensive. CT can answer the appropriate questions in most cases.

The role of imaging in assessing candidates for supraglottic and vertical hemilaryngectomies will be discussed. The major advantages of MRI are the ability to determine early cartilage invasion and the utilization of coronal scanning to assess the ventricle. The abilities of CT and MRI to define tumor extension across the ventricle, tumor extension to the level of the cricoid, and deeper extension either into the cartilage or into the extralaryngeal tissues will be emphasize& Mention will be made of the strengths and weaknesses of magnetic resonance and CT.

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CONTRAST ENHANCED COMPUTED TOMOGRAPHY IN PRETHERAPEUTIC T-STAGING OF LARYNX AND HYPOPHARYNX TUMORS. M.Lenz; B.Kersting-Sommerhof; W. Bautz; M . S t r o t z e r Dept. o f Radiology, Technical U n i v e r s i t y Munich, Germany

MRI IN THE STAGING OF LARYNGEAL CARCINOMA F.Campodonico, C.Della Rocca*, A.Vidirl, A.Greco**, M.Santarellb R.Guerrisi Istituto di Radiologia, di *Anatomia Patologica e di **ORE, Universita"La Sapienza", Rome, Italy

Purpose: CT examinations o f 119 p a t i e n t s with laryngeal (71) and hypopharynx (48) tumors were analyzed r e t r o s p e c t i v e l y t o assess the r o l e o f c o n t r a s t enhanced CT in the p r e t h e r a p e u t i c t - s t a g i n g in comparison and supplemental %o c l i n i c a l e v a l u a t i o n . Method: CT scans were obtained w i t h a scan time o f 1-3 sec and 4-5 mm s l i c e thickness in contiguous scanning. Contrast media were applied as a 50 mI bolus i n j e c t i o n followed by 100 ml f a s t i n f u s i o n (300 mg I o d i n e / m l ) . Images were taken during q u i e t breathing and E-phonation. Size, demarcation, expansion, i n f i l t r a t i o n of landmark s t r u c t u r e s and c a r t i l a g e d e s t r u c t i o n were defined f o r each lesion. Results: CT (69%) was i n f e r i o r t o c l i n i c a l e v a l u a t i o n (75%) in the t - s t a g i n g o f small and s u p e r f i c i a l l y located tumors. CT (93%) was s u p e r i o r t o c l i n i c a l evaluation (29%) in the t - s t a g i n g o f l a r g e r masses and r e l i a b l y demonstrated d e s t r u c t i o n o f c a r t i l a g e as well as tumor infiltration i n t o deeper compartments. C l i n i c a l methods - including endoscopy - usually underestimated the actual tumor size. A combination o f c l i n i c a l and CT f i n d i n g s in t-staging resulted in a s e n s i t i v i t y o f 93% at a s p e c i f i c i t y o f g8%. Conclusion: Contrast enhanced CT in combination with clinical e v a l u a t i o n is a r e l i a b l e basis f o r therapy planning, prognostic outlook and c l i n i c a l - t h e r a p e u t i c studies.

40 patients affected by laryngeal carcinoma underwent MRI, with 1.5 T superconductive system (Philips Gyroscan), installed of LN.I., Rome. A circular surface coil, a field of view of 20x20 cm and 256x256 matrix were utilized. The images were obtained with SE technique, Tl-weighted sequences (TR 550 msec., TE 30 msec.) with axial, saglttal and coronal planes, with 4 averages and T2-weighted sequences (TR 1800 msec., TE 30-?0 msec.) with axial planes, with 2 averages. In 15 cases the examination was completed throuah Gd-DTPA i.v. Among the 40 patients examined, 7, presented supraglottie, 23 g|ottic and 10 subglottic neoplasms. MR[ has showed the tumour in 3.5 cases, with homogeneous intermediate signal intensity in the Tl-weighted sequences, higher than the signo! intensity of rnusou]ar tissue, but lower than that of fat. The T2-weighted sequences presented a lower S/N, showing the neoplasms as lesions with less homogeneous signal intensity. The extension to the laryngeal cartilage in 12 cases, to the intralaryngeal compartments in 14 cases and extralaryngea[ structures in ? cases was proved. In 5 patients with T1 NO, the MRI showed no signal alternation referrab/e to neoplastic tissue. In our experience the Gd-DTPA showed no advantage in connection to the examination without re.d.c. The MRI, although it is more influenced than CT by movement artefacts because of longer acquisition times, gives an excellent detail of intra- und extralaryngeal structures and of laryngeal cartilages, which makes it the choice images methodology in study of laryngeal tumours.

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45 Sjoegren's disease of the parotid gland - correlation of MR imaging, clinical and palhological findings T.VogI,MD; S.DreseI,MD; M.Spaeth,MD; G.Grevers,MD; Jlissner,MD University of Munich, Dep.of Radiology West-Germany 8000 Munich 2, Ziemssenstro2

Purpose: Up to now in the diagnostic management of myoepithelial sialoadenltis (Sj6gren's-syndrome) sialography was demanded as an essential imaging method. Now, first results of MR imaging in these disease may offer new poSSibilities in diagnostic imaging.

Material and Methods: Fourty-two patients suffering from immunohistotogical and serological ensured Sj~gren's-syndrome were examined in transverse and coronal orientation. Images were obtained plain and after Gd-DTPA administration by Tl-weighted sequences (TR/TE= 5(30/25 ms) and by plain T2- weighted sequences ffR/TE= 1600/90 ms).

Results: In acute stages plain T2-weighted images showed a swollen gland with prolonged T2-relaxation tines and high signal intensity in these images, tn chronic stages, a gland of normal size and also prolonged T2-relaxation times could be seen. Additionally, in all cases there was a non-homogeneous internal pattern with a characteristic speckled, honeycomb-like appearence, especially in T2-weighted images. After administration of Gd-DTPA no additional information was extracted. Our experience rendered possible to develop 4 stages to diagnose Sj6gren's-syndrome in differentiation to inflammatory changes (no characteristic changes - nodular and swollen gland).

Conclusion: In a preliminary study the typical appearence of Sj6gren'ssyndrome allows to differentiate this disease from inflammatory changes as well as from tumors using plain T1- and T2-weighted sequences. Administration of Gd-DTPA does not lead to advantageous diagnostic results.

46 GADOLINIUM-ENHANCEMENT IN CRANIOFACIAL FIBROUS DYSPLASIA J.W. Casselman*, J. Vanvuchelen**, L, Neyt °, G. D'Eont °* Department of Radiology*, Pathology**, Maxillofacial Surgery ° and 0torhlnolaryngology °° A.Z. St. Jan Brugge, Belgium This study was performed to find out if enhancement is constant in craniofaclal Fibrous Dysplasla (F.D.) a n d if a correlation exists with I)TI and T2 signal intensities 2)histology 3)cllnlcal activity of the lesion. Five patients with craniofacial F.D. (mandible-maxillaorbital roof-spheneid bone-temporal bone) underwent a MR study. The signal intensities of the lesions on TI- and T2-weighted images were compared to brain tissue. Enhancement was evaluated as moderate or marked (hypolntense or iso/hyperlntense compared to fat respectively). In all patients the diagnosis was confirmed by biopsy. Enhancement after intravenous Gadolinium adminlstratlon was present in all patients but marked enhancement was only seen in two patients. Clinically these two patients had faster growing lesions and in one of them the lesion was already hyperintense on the T2-weighted images (corresponding to metabolically active tissue according to J.A. Utz et el.). Hemorrhagic regions were found in two patients and a cystic lesion was present in one patient. "Fibrous Dysplasla" lesions exhibit moderate or marked enhancement, explained by the small vessels and peripheral sinusoids often seen histologically, Correlation of lesion activity with pathological findings was not possible (only small biopsies were available) hut lesion activity could well be represented by marked Gd-enhancement and hyperlntensity of the lesion on T2-welghted Image s.

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POSTSURGICAL NRI EVALUATION OF PATIENTS TREATED WITH COMBINED CRANI0 - FACIAL RESECTION R. Musumeci, L. Balzarini, G. Cant~, E. Ceglis, M.I. Grosso, F. Mattavelli, R. Petrillo, Y. Reiner, C.L. Solero ~, J.D. Tesoro Tess National Cancer institute - Milano, Italy

UNUSUAL CAUSES OF EPISTAXIS B. Azar-Kia, S. Horowitz, M. Fine, J. Delgado Loyola University Medical Center, M~ywood, Illinois

High field MRI was performed in 20 patients treated with combined cranio-facial resection of the anterior and middle cranial fosssl, mainly for malignant tumors arising from the paranasal sinuses or from the regional soft tissues and invading the bone structures. The brain was than sustained by the pericranial membrane while the surgical breach was filled with fibrin glue, fat tissue or revascularized myocutaneous flap. A comparison with other imaging modalities such as plain film or CT was performed. With MRI the assessment of the surgical limits of the procedure, the evaluation of the different prosthetic tools and surgical complications such as persistent or hypertensive pneumoencephalus, brain hematoma or abscess, meningitis, ecc. was very easy due to its multip]anar end multipsrametric properties.

The purpose of this paper is to discuss unusual cases with primaz:f clinical presentation of epistaxis. These include: rilotured aneurysnl of cavernous portion of the internal carotid artery which was treated by balloon embolization, a case of aneurysmal bone cyst in the nasal cavity treated by presurgical embolization followed by total resection, and a case of hemangioma also treated by er~oolization and surgical resection. We are also presenting rare cases of metastasis to the nasal cavity by hypernephronm and melanoma.

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49 COMPARATIVE CLINICAL AND RADIOLOGICAL STUDY OF TRAUMA OF THE SKULL BASE R. Roig, C, R. Guirado, G. Garcfa I n s t i t u t o de Tomodensitometrfa, Barcelona, Spain Twenty cases of skull base trauma were studied with CT, and a comparison was made between the radiological findings and the clinical evolution, with special interest in lesions of the facial nerve. The topography of the fracture line along the fallopian canal was correlated with the post traumatic sequelm.

ULTRA-~FASTMRI OF THE UPPERAIRWAY DURINGACTIVE RESPIRATION: APPUCATION FOR EVALUATIONOF OBSTRUCTIVE SLEEP APNEA CJ SCHATZ, FG SHELLOCK, P JULIEN, TKF FOO CEDARS-SINAI MEDICALCENTER, LOS ANGELES, CA USA Patients with obstructive sleep apnea (OSA) have at least 30 episodes of apnea during seven hours of sleep. In some patients, apneic episodes can occur as many as 500 times during a single night's sleep. With OSA there is often pathological narrowing of the pharyngeal airway either at the soft palate-uvula or at the tongue base. Because of restraints in temporal resolution, conventional MRI has not been shown to be useful for evaluation of OSA patients. Recently, faster MRI methods have been developed. Therefore, we evaluated the upper airway of 7 patients with suspected OSA using ultrafast spoiled grass (SPGR) MRI (TE - 3 msec, TR - 7 msec, bandwidth - 16 KHZ) in the mid-sagittal plane and multiple axial planes from the nasopharynx to the hyoid bone. Images were obtained at the rate of 1 per sec for 12 sec at each slice location so that airway dimensions could be observed on a cine-loop display during active respiration. Abnormal narrowing of one or more portions of the upper airway was observed in 6 of the 7 patients studied. Imaging the upper airway during active respiration by ultrafast SPGR - MRI appears to be an extremely useful method for assessment of patients with OSA.

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51 I M P A C T OF T O N G U E H Y P E R T R O P H Y IN APNEIC PATIENTS

Authors : K. MARSOT-DUPUCH,, F. CHABOLLE, X. LASHIVER, A.T. IYRIB0Z. H6pital Saint-Antoine (PARIS)

OBSTRUCTIVE SLEEP APNEA SYNDROME: CEPHALOMETRIC FINDINGS M. de l a Fuente; L. Dominguez; J. Campollo; A. Ramos; J. Ferrando. Hospital 12 de Octubre. Obstructive sZeep apnee syndrome (OSAS) i s e progressive di sor der characterized by episods

of

r e s p i r a t o r y a r r e s t during sleep, s n o r i n g , d i s o r g a -

PUEPOSE =-To d e m o n s t r a t e reduced o r o p h a r y n g e a l a i r w a y by tongue h y p e r t r o p h y in apneic s n o r e r s explaining failures of uvulopharyngoplasty. MATEEL4LS AND METHODS : We analysed soft tissues and bony structures by MRI (Massiot Philips 1,5 T) coronal and axial TI W.I. ; 5 mm thickness. We explored 27 apneic patients, 12 non apneic snorers, and 15 normal voluntary subjects. All came from the same snoring center and had a study of sleep, The mean of apneic rate was 47. We stastistically compared tongue thickness in sus and submandibular area, tongue axis, location of hyoid bone referred to mandibular bone and cervical spine, EES/ILTS : In apneic, patients t o n g u e h y p e r t r o p h y was p r e v a l e n t in sub mandibular a r e a compared to non apneic snorers and normal s u b j e c t (p<0,001).This finding was associated with a n t e r o inferior displacement of hyoid bone. These abnormalities p r o g r e s s i v e l y increased between snorers and apneic subjects. C O N C L U S I O N S =- This may explain c e r t a i n failures of uvulopharyngoplasty and ask for new surgical procedures, as hemibasiglossectomy.

nizes sleep pattern and excessive

daytime sleep-

ness. Craneofacial and oropharyngeal s o f t

tissue

p r o f i l e s were studied by cephalometric analysis i n pat i ent s with OSAS and c o n t r o l s . The anatomical abnormalities most f r e c u e n t l y found were micrognatia and r e t r o g n a t i a , descended p o s i t i o n o f the hyoid bone, and a l t e r a t i o n s i n the s o f t palate lenght. We conclude t h a t cephalemetric studies are very usuful in the management o f pat i ent s

with

OSAS, showing the underlying pathology and helping in planning the s u r g i c a l procedure.

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Scientific Session: Dental- and Maxillo-Facial Complex Moderators: G. Lloyd, London, United Kingdom and E.E. Kassel, Toronto, Canada

04.00 p m - 04.15 pm

Keynote Address: Subtraction Magnetic Resonance for Tumors of the Skull Base and Paranasal Sinuses G. Lloyd, London, United Kingdom

04.15 pm-05.30 pm

Scientific Papers 53 - 62

04.15 pm-05.30 pm Scientific Papers 53-62 053 The naso-frontal duct: A CT evaluation in the sagittal plane

058 Inflammatory pseudotumor of the maxillary sinus. Report of three cases

E Veillon, M. Bintner, E Bourjat, P. Baur, Strasbourg, France

M. Ida, S. Tada, M. Ariizumi, 1". Tatsuno, K. Fukuda, G. Kaneko, T. Kato, T. Nikaido, Tokyo, Japan

054 Fractures of the nasolacrimal duct J.M. Unger, Madison, USA 055 High-resolution MR- and CT-imaging of the pterygopalatine fossa B. Schuknecht, A. Lukes, P. Huber, Bern, Switzerland 056 The use of gadopentate dimeglumine enhanced MR for differentiating mucoceles from neoplasms in the paranasal sinuses C. E Lanzieri, M. Shah, D. Krauss, P. Lavertu, Cleveland, USA (Abstract withdrawn) 057 Use of gadolinum enhanced MRI for differentiating inflammatory from neoplastic sinus disease: analysis of the irregular enhancement pattern C.E Lanzieri, R. Gilkeson, R.W. Tart, A.S. Smith, B. Kaufman, Cleveland, USA (Abstract withdrawn)

059 MRI in the evaluation of the lesions of paranasal sinuses E Campodonico, G. Bandiera, R. Guerrisi, A. Vidiri, M. Santarelli, Rome, Italy 060 Inflammatory diseases (ID) of nose and paranasal sinuses

(N-PS): The role of CT S. Perugini, M.G. Bonetti, U. Salvolini, V. Pace, S. Ghirlanda, T. Scarabino, G.M. Giannatempo, Ancona, Italy 061 Primary lymphoma of facial sinus B. Azar-Kia, S. Horowitz, M. Fine, J. Delgado, Maywood, USA 062 Incidental detection of brain tumors on CT scans of the paranasal sinuses S.B. Fierstien, Beverly Hills, USA

S??

Keynote address SUBTRACTION MAGNETIC RESONANCE FOR TUMOURS OF THE SKUI~ BASE AND P ~ J ~ A S A L SINUSES GA Lloyd a~ud t ~ Barker Royal National Throat, Nose and Ear Hospital,

53 THE NASO-FRONTALDUCT : A C.T. EVALUATION IN THE SAGXTI'AL PLANE (ABOUT 35 PATIENTS) F. VEILLON, M. BINTNER, P. BOURJAT, P. BAUR CHU - STRASBOURG

London The subtraction method of Ziedses des Plantes has been applied to Gadolinium enhanced magnetic resonance imaging (GdMR). Using short acquisition times, T1 weighted spin echo sequences are made immediately before and immediately after the intravenous administration of I0 ccs. of Gadolinium DTPA. To avoid moving the patient from the scanning tunnel the venipuncture is made into the dorsum of the foot. The needle is placed in the vein prior to patting the patient in the scanner and is irrigated with saline while the control series is obtained. 20 patients with naso-sinus or skull base turnouts have been investigated successfully by this technique and satisfactory subtraction studies are now obtained on all patients other than the claustrophobic. Subtraction GdMR provides the best demonstration of the effects of Gadolinium on the NMR signal for beth normal and abnormal tissues. The densities recorded on the subtraction image are dependent on tissue blood supply and provide a more accurate record of tumour extent than that shown by unsubtracted GdMR scans.

Purpose : Evaluation of C.T. in the exploration of the naso-frontal duct (NFD) with reformated s a g i t t a l sections. Mater~a|s and methods : 35 patients are examined with C.T. to evaluate the NFD with reformated s a g l t t a l sections obtained from axial sections p a r a l l e l to the bony palate. On average, 40 slices are obtained with an increment of 0.5 mm at 240 mAs. Results : The NFD drains the f r o n t a l sinus, following an anteroposterior and supers-inferior oblique direction, ending in the anterior portion of the middle meatus, the obliqueness being variable. C.T. shows with a sensitivity of 100 %, a canal in the posterior half of the NFD close to the aperture in the middle meatus. On the contrary, the anterior half may be t o t a l l y visible as a duct or replaced by an ethmoidal c e l l . Oblique coronal refsrmated sections of the NFD complete this study, but do not bring additional information. Conclusion : The sagittal reformated C.T, sections allows a precise evaluation of direction, length and aperture of the NFD in the middle meatus ; i t is thus a new reliable method for the study of this region.

54

55

FRACTURES OF THE NASOLACRIMAL DUCT J. M. Unger University of Wisconsin - Madison Medical School

HIGH RESOLUTION MR- AND CT-IMAGING OF THE PTERYGOPALATINE FOSSA Schuknecht B. I, Lukes A. 2, Huber p ]

Fractures of the nasolacrimal duct may accompany a variety of severe midface fractures, naso-fronto-ethmoid fractures, and certain types of orbital fractures. We believe that this injury is more common than ordinarily assumed, and easily overlooked in the presence of more obvious facial fractures. The lacrimal sac is lodged in a groove formed by the lacrimal bone and frontal process of the maxilla; the nasolacrimal duct is contained in a bony canal formed by the maxilla, lacrimal bone and inferior nasal concha. The frontal process of the maxilla is a strong bone which when fractured tends to fracture around, rather than through the nasolaerimal duct. The duct is more likely to be injured in fractures involving the inferomedial portions of the maxilla, lacrimal bone and inferior nasal concha. Since unrecognized injury to the canaliculus may eventuate in fibrosis with scar eontracture making subsequent repair impossible, it is important to identify the fracture as expeditiously as possible, in order that any necessary reconstruction can be done at the time of initial surgery. In this presentation we report our experience with fractures of the nasolacrimal duct, associated injuries and complications.

Dept. of Neuroradiology {I), Dept. of Neurosurgery (2), Inselspital Bern The pterygopalatine fossa (PPF) is a hidden, predominantly bone lined space located at the junction of the skull base and midfacial skeleton. As a network of neurovascular st~actures the PPF interconnects to the orbit, middle cranial fossa, nasal and oral cavities and infratemporal space through bony canals and openings. In current skull base surgery delineation of tumoral invasion facilitates the preoperative planning of multidisciplinary approaches and offers the possibility of radical resection. Both CT and MRI were used in 7 volunteers to study bony landmarks and neurovascular structures of the PPF.CT-examinations were performed with 1,5mm axial and coronal slices. MR-studies comprised T1weighted contiguous 3 mm slices in axial, coronal and sagittal planes. The bony borders, canals and openings of PPF were readily visualized by CT. In addition, CT with bone algoritb~ provided detailed delineation of thin bony boundaries in the adjacent region of the P PF. MR proved to be superior in soft tissue resolution. High signal intensity of fat allowed exact discrimination of the maxillary artery and its division as well as the pterygopalatine ganglion with its branches. The neurovascular contents o~ the foramen sphenopalatinum and rotundum were delineated in all axial and coronal MR-examinations. Multiplanar MRimaging is particularly advantageous to delineate topographic relations of the pterygopalatine fossa to adjacent sinuses, the orbit, middle cranial fossa and infratempora! compartment. Knowledge of the exact anatomy of the PPF visualized by CT and MR may offer earlier recognition of invasion, osseous destruction and perineural extension of soft tissue skull and midface tumors.

S 78

56

57

Abstract withdrawn

Abstract withdrawn

58

59

INFLAMMATORY PSEUDOTUMOR OF THE MAXILLARY

NnI

SINUS. REPORT OF THREE CASES. M. Ida, S. Tada, M. Ariizumi, T. Tatsuno, K. Fukuda, S. Kaneko, T. Kato, T. Nikaido Department of Radiology, ENT and Pathology, The Jikei University School of Medicine We recently encountered 3 cases with chronic inflammatory disease of the maxillary sinus radiologically and clinically simulating a malignant tumor. Histologically there were conglomerated foci of dilated capillaries, hemorrhage, necrosis, inflammatory edema, and fibroblastic reaction, forming a secondary pseudotumor as a result. Complexities of the MR signal intensity within the mass were considered to be reflected by a variety of these histological appearances. Fibrous histiocytoma and rhabdomyosarcoma which also show inhomogeneous histological appearances should be included in the differential diagnosis. Three cases were 17 y/o female, 19 y/o male, and 56 y/o male presenting with nosebleed and cheek swelling. The sinus films showed unilateral opacification of of the paranasal sinuses and nasal cavity. CT showed expansile mass occupying the maxillary antrum with suggestion of sinus wall erosion. External carotid angiography showed minireal fine vascularity suggestive of chronic inflammation in one case. MRI showed markedly irregular texture of the mass with mixed high, intermediate and low intensities. The part of high intensity on T2weighted image was markedly enhanced after Gd-DTPA in one case.

I N THE EV~LUA-I'ION OF THE L E S I O N S OF P A R ~ A S A L S I N U S E S

F. C~podonico, G. B a n d i e r a ~ R. Guerrisi, A, Vidiri, M. 5antavelli. (Istituto di Radiologia e I C l i n i c s Otorinolaringo~a%Pia, Universita' "La 5 a p i e n z a ~', Rome, Italy.) S5 patients a f f e c t e d by inflammatory and neoplastic processes of paranasal sinuses underwent MRI, with a s u p e r c o n d u c t i v e s y s t e m (Philips Gyroscan) o p e r a t i n g a% 1.5 T, installed at I.N.I., Rome-. The images w e r e obtained with SE techique~ T I (TR 550 msec~ T£ 30 msec) a n d T 2 - w e i g h t e d sequences (TR 1800 msec~ ~ 30-90 reset), with axial, coronal and 5agittal planes, accordin~ to situations. A h e a d coil and a m a t r i x of 25Sx255 were utilized. In 20 cases it was a matter of inflammatory processes (polypuses, mueoceles, retained secretion) and in 15 patients of neoplasm5 (14 c a r c i n o m a and I cystoadenom~). In some cases the e x a m i n a t i o n was completed through C ~ d - D ~ i.v. The neoplasms of pavanasal sinuses are often associated to f]ogistic processes, secondary to the O b S t r u c t i o n of os%ia or nasal cavity. Inflammatory p a t h o l o g y has caused a high slgna] intensity in the T2-weighted sequences~ while the tumors have presented a l o w - t o - i n t e r m e d i a t e signal i n t e n s i t y on both Tl and T 2 - ~ i g h t e d image~ s h o w i n ~ enhancement w i t h Od-D]-PA y~t lower than that cf the mucosa, while the retained secretion h a s no enhancement after contrast. think that MR should be ~ r e frequently utilized in the study of paranasal sinuses since this m e t h o d o l o g y allows us to define with p r e c i s i o n the e x t e n s i o n of neoplastic processes and the d i f f e r e n t i a t i o n b e t w e e n the5e and other pathological conditions such as inflammations or retained secretion.-.

S 79

6O

61

I N F L A M M A T O R Y D I S E A S E S (ID) O F N O S E A N D P A R A N A S A L S I N U S E S (N-PS): T H E R O L E O F CT S.Perugini§,M.G.Bonetti*,U.Salvolini°,V.Pace§, S.Ghirlanda§,T.Scarabino*,G.M.Giannatempo* R a d i o l o g y D p t s . , § U S L ~ P e s a r o Hosp. and *CSS S a n G i o v a n n i R . ( F G ) H o s p . . ° N e u r o r a d i o l o g y Dpt. U S L 12 T o r r e t t e di A n c o n a Hosp.. I t a l y

PRIMARY LYMPHOMA OF FACIAL SINUS B. Azar-Kia, S. Hororwitz, M. Fine, J. Delgado loyola Uni%~.rsity Medical Center, Man,pod, Illinois

P r o j e c t i v e r a d i o l o g y (PR) is u s u a l l y e m p l o i e d as f i r s t s t e p d i a g n o s t i c p r o c e d u r e in ID of N-PS, b u t its l i m i t s in d i f f e r e n t i a l d i a g n o s i s a n d spac i a l b a l a n c e a r e w e l l known. A i m of the p r e s e n t r e p o r t w a s p r o v i n g h o w CT c a n g e t o v e r PR limits. 107 pts. w e r e a n a l y z e d b y C T ( o c c l u s a l l i n e , 1 0 m m s l i c e s , w i t h o u t C E ) ; a m o n g t h e m 25 a l s o u n d e r w e n t C o m p u t e d R a d i o g r a p h y (CR),37 c o n v e n t i o n a l PR a n d 30 a l s o 5 a n d 2 m m s l i c e CT w i t h C E , i n c a s e of suspected expansile lesions. C R w a s s u p e r i o r t o c o n v e n t i o n a l P R , b u t CT w a s far a b o v e t h e t w o of t h e m ( r e s u l t i n g as ist c h o i ce t e c h n i q u e ) d u e to the f o l l o w i n g a d v a n t a g e s : s u perior anatomical depiction and sensitivity,easy i d e n t i f i c a t i o n of c o n c o m i t a n t e x p a n s i l e l e s i o n s , low d o s i m e t r i c c o s t , o p t i m a l s p a c i a l b a l a n c i n g bef o r e s u r g i c a l o r m e d i c a l t r e a t m e n t a n d in t h e f o l low-up. A b o u t CT t e c h n i q u e , a 10 m m s l i c e a l g o r i t h m is u s e f u l in o b t a i n i n g a p a n o r a m i c s t u d y , t h a t s h o u l d be c o m p l e m e n t e d w i t h a 5 m m s l i c e one in ID p o s i t i v e or d o u b t c a s e s . W h e n an e x p a n s i l e les i o n is s u s p e c t e d , a 2 m m s l i c e , b o n e a l g o r i t h m p r o g r a m , w i t h C E and c o r o n a l and s a g i t t a l M P R is s u g g e s t e d , a s t h e s e i m a g e s are v e r y u s e f u l w h e n m i c r o s u r g e r y is p r o g r a m m e d .

62 INCIDENTAL DETECTION OF BRAIN TUMORS ON CT SCANS OF THE PARANASAL SINUSES S.B. Fierstien, M.D. Beverly Hills, California Direct coronal CT scanning of the paranasal sinuses using hard bone algorithm and magnification collimating the field of view to the paranasal sinuses has become the gold standard for imaging of the paranasal sinuses and their drainage pathways. This study was undertaken to determine if filming the non-magnified images of the entire field of view (including the brain) with soft tissue windows is worth even the minimal additional time and cost. To this end all studies were performed with magnified bone windows as well as the non-magnified soft tissue windows of the brain. Cases will be shown of brain tumors visible only with the non-magnified soft tissue windows. Although these eases represented a small percentage of the total patients scanned, the positive findings have caused us to conclude that the small increment in cost in printing the additional images is worthwhile.

We are presenting cases of primary lynphema arising from ethmoidal and maxillary sinuses. C.T. in the early stage showed a hcmogeneous mass in the sinuses, and later bone erosion and extension to adjaoent soft tissue was identified. MI%I revealed isointense soft tissue mass on T1 and high inte2~ity on T2 weighted images. After injection of Gadolinium contrast enhancement was noted. Primary lynphoma of facial sinuses are uncc~mon. CT and MR! findings are not specific. These lesions can not he differentiated from other aggressive pathology in the sinuses. Primary lynlohoma should he considered in t/he differential diagnosis of an aggressive sinus lesion in young sdults.

XVIIth CONGRESS OF THE EUROPEAN SOCIETY OF NEURORADIOLOGY October 8-12, 1991 Honorary President: M.G. Ya~argil President: A. Valavanis Scientific Program Committee ESNR

International Advisers

G. du Boulay, London (Chairman) E.A. Cabanis, Paris S. Holtfis, Lund L. Picard, Nancy G. Scotti, Milano A. Valavanis, Zurich J. Valk, Amsterdam

G. Di Chiro, Washington D.C. D. Harwood-Nash, Toronto A.N. Hasso, Loma Linda T.P. Naidich, Miami M. Takahashi, Kumamoto A. Thron, Aachen R.A. Zimmerman, Philadelphia

o

The m st prectse diagnosis o f C N S diseases W. J. Huk, Erlangen; G. F. Gademann, Heidelberg; G. Friedmann, Cologne

Magnetic Resonance Imaging of Central Nervous System Diseases Functional Anatomy- Imaging- Neurological Symptoms - Pathology

1990. XVIII, 450 pp. 614 figs. in 822 sep. illus. 24 tabs. Hardcover DM 480,ISBN 3-540-17641-1 This book provides an outstanding description of diseases of the central nervous system (CNS) and their presentation by magnetic resonance imaging (MRI). Stress is laid upon neuropathological peculiarities of the diseases, knowledge of which is of great importance for the correct evaluation of their impact on signal intensity and for the choice of adequate imaging parameters. The clinical section is preceded by a list of leading neurological symptoms and their topical correlations which serves to obtain accuracy not only in formulating diagnostic questions, but also in performing the examination. The excellent detailed presentation of the anatomy of the CNS in the MR image allows a more profound study of the relationship between the site of the lesion and its effects on function, and with it, the symptoms, than has ever been the case in existing radiologicat books. D i s t r i b u t i o n rights for J a p a n : I g a k u Shoin, T o k y o

Heidelberger Platz 3, D-1000 Berlin 33 [] 175 Fifth Ave., NewYork, NY 10010, USA [] 8 Alexandra Rd., London SW19 7JZ, England [3 26, rue des Carmes, F-75005 Paris 13 37-3, Hongo 3-ehome, Bunkyo-ku, Tokyo 113, Japan D Citicorp Centre, Room 1603,18 Whitfield Road, CausewayBay, Hong Kong D Avinguda Diagonal, 468-4°C, E-08006 Barcelona

S 83

The European Society of Neuroradiology The European Society of Neuroradiology (ESNR) was founded on September 5, 1969 dqrj~ng a meeting which took place in Colmar, France upon the initiative of Drs. Jean-Paul Braun, Colmar and Auguste Wackeaheim, Strasbourg and the guidance and support of Professor George B. Ziedses des Plantes, Amsterdam. The following purposes of the society were unanimously adopted by the 68 Founding Members: 1. To promote Neuroradiology by appropriate means 2. To coordinate work and documents in Neuroradiology and to assure the dissemination there of throughout the countries of Europe 3. To coordinate the relationships among General Radiology and the Clinical Neurosciences 4. To contribute toward unified methods of teaching Neuroradiology and unified standards for, training and certification in Neuroradiology 5. To promote and coordinate relationships with the European National Neuroradiological Societies, and to promote the foundation of National Neuroradiological Societies or National Sections of the ESNR in the countries in which there are no existing societies 6. To form European research teams to deal with specific neuroradiological questions Full membership in the ESNR is open to those pyhsicians who have completed at least two years of formal training in Neuroradiology and who spend more than half of their clinical and research time in the practice of Neuroradiology in a European country. There are presently 617 members in all categories.

Founding Members 17. Amundsen, Norway P. Andersen, Denmark H. Backmund, Germany K. Bergstr6m, Sweden V. Bernasconi, Italy A.S. Bligh, United Kingdom G. Bonte, France J. Bories, France G. Bradac, Germany J.P. Braun, France P. Buffard, France J. W. D. Bull, United Kingdom E.H. Burrows, United Kingdom A. Calabro, Italy R. Chrzanowski, Poland G. Corn61is, Belgium S. Cronqvist, Sweden K. Decker, Germany P. Dettori, Italy R. Djindjian, France A. Donaldson, United Kingdom G. du Boulay, United Kingdom J. Duquesne1, France

Ph. Engel, France L. Escudero, Spain H. Fischgold, France T. Greitz, Sweden G. Gryspeerdt, United Kingdom H. Hacker, Germany D.T. Hawkins, United Kingdom R. Hoare, United Kingdom P. Huber, Switzerland H.H. Jacobsen, Denmark L. Jeanmart, Belgium J. Jirout, Czechoslovakia E.M. Klausberger, Austria J. Legr~, France B. Liliequist, Sweden E. Lindgren, Sweden G. Lombardi, Italy J. Metzger, France P. Moxon, United Kingdom D. Mt~ller, Germany R. Oberson, Switzerland A. Passerini, Italy L. Penning, Netherlands

J. Petrov, Germany L. Picard, France P. Potthoff, Germany L. Psenner, Austria R. Reid, United Kingdom J. Roulleau, France M. Roth, Czechoslovakia R. Ruggiero, Italy G. Salamon, France W. H.T. Shepherd, United Kingdom J. Simon, France E Smaltino, Italy J. Sol6-Llenas, Spain A. T~inzer, Germany A. Thibaut, Belgium H. Vogelsang, Germany A. Wackenheim, France S. Wende, Germany G. Westberg, Sweden I. Wickbom, Sweden O. Wiedemann, Germany G.B. Ziedses des Plantes, Netherlands

1990-1993 Board, Delegates and Committees Board of the ESNR

Honorary Presidents

Advisory Board

President Jean-Paul Braun

George B. Ziedses des Plantes Giovanni Ruggiero Auguste Wackenheim George du Boulay Sten Cronqvist

M. Leonardi, Chairman D. Bal~riaux E.A. Cabanis O. Flodmark C. Manelfe

Vice-President Uwe Piepgras Secretary General Anton Valavanis Assistant Secretary Pierre Lasjaunias Treasurer Peter Huber

S 84 National Delegates Austria Belgium Czechoslovakia Denmark Finland Germany France

E. Schindler D. Bal&iaux P. Kalvach J. Praestholm E. Laasonen H. Hacker L M. Cailld

A. Gouliamos G. D6ak G. Scotti J. Valk R. Dullerud L Zajgner A. Goulao

Greece Hungary Italy Netherlands Norway Poland Portugal

Spain Sweden Switzerland United Kingdom Yugoslavia

L Ruscalleda S. Holffts O. Schubiger B.E. Kendall M. Lovrencic

Committees

Research Committee J.M. Cailld, Chairman U. Salvolini

Training Committee J. Ruscalleda, Chairman J.F. Bonneville D. Bal6riaux S. Cronqvist H. Hacker B.E. Kendall C. Raybaud G. Scotti

Rules Committee U. Salvolini, Chairman L P. Braun, ex officio P. Huber, ex officio P. Lasjaunias, ex officio U. Piepgras, ex officio A. Valavanis, ex officio

Program Committee G. du Boulay, Chairman E.A. Cabanis S. Holffts L. Picard G. Scotti A. Valavanis J. Valk

Interventional Neuroradiology Committee J. Moret, Chairman G. Belloni J.E Bonneville H.L. Espinet Elizalde M. Guimaraens Martinez I.M. Holland B.E. Kendall D. Ktihne P. Lasjaunias L L Merland A. L Molyneux M. Nadjmi L. Picard G. Scialfa G. Scotti P. Svendsen T.G. Tjan A. Valavanis H. Zeumer

Past Presidents George B. Ziedses des Plantes, Amsterdam James W.D. Bull, London (deceased) Giovanni Ruggiero, Bologna Per Amundsen, Oslo (deceased) Auguste Wackenheim, Strasbourg George du Boulay, London Sten Cronqvist, Lund Jean-Paul Braun, Colmar

•969-1972 1972-1975 1975-1978 •978-1981 1981-1984 1984-1987 1987-1990 1990-1993

Past Officers 1969 -1972 President:

Vice-President: Secretary General: Assistant Secretary:

George B. Ziedses des Plantes, Amsterdam James W.D. Bull, London Auguste Wackenheim, Strasbourg Jean-Paul Braun, Colmar

1972-1975 President: Vice-President: Secretary General: Assistant Secretary:

James W.D. Bull, London Giovanni Ruggiero, Bologna Auguste Wackenheim, Strasbourg Jean-Paul Braun, Colmar

1975 -1978 President: Vice-President: Secretary General: Treasurer:

Giovanni Ruggiero, Bologna Per Amundsen, Oslo Auguste Wackenheim, Strasbourg Jean-Paul Braun, Colmar

1978-1981 President: Vice-President: Secretary General: Treasurer:

Per Amundsen, Oslo Auguste Wackenheim, Strasbourg Jean-Paul Braun, Colmar Peter Huber, Berne

$85 1987 -1990

1981-1984

President: Vice-President: Secretary General: Assistant Secretary: Treasurer:

Auguste Wackenheim, Strasbourg George du Boulay, London Jean-Paul Braun, Colmar Uwe Piepgras, Homburg Peter Huber, Berne

President: Vice-President: Secretary General: Assistant Secretary: Treasurer:

Sten Cronqvist, Lund Jean-Paul Braun, Colmar Uwe Piepgras, Homburg Ugo Salvolini, Ancona Peter Huber, Berne

1984-1987

President: Vice-President: Secretary General: Assistant Secretary: Treasurer:

George du Boulay, London Sten Cronqvist, Lund Jean-Paul Braun, Colmar Uwe Piepgras, Homburg Peter Huber, Berne

Congress of the European Society of Neuroradiology The European Society of Neuroradiology holds each year a scientific congress at a place and date designated 135,the Board. The business meeting (general assembly) of the society is held in conjunction with this annual scientific congress. Since its creation in 1969, the ESNR organised 17 scientific congresses. In recognition of the importance of the Symposium Neuroradiologicum, which is held every four years, no scientific congress of the ESNR was held in the year of a meeting of the Symposium. Overall attendance of the ESNR annual Congress was from 162 participants in 1969 to more than 300 in 1991.

Ist Congress September 6, 1969 Colmar, France Presidents: J. E Braun, A. Wackenheim

VIIth Congress September 9-10, 1977 Barcelona, Spain President: M. Rovira

XIllth Congress September t l - t5, 1985 Amsterdam, Netherlands President: J. Valk

IInd Congress September 24-25, 1971 London, Great Britain President: J.D.W. Bull

VIIIth Congress September 7 - 8 , 1979 Strasbourg, France President: A. Wackenheim

XIVth Congress September 8-12, 1987 Udine, Italy President: M. Leonardi

IIIrd Congress Auguste 23-24, 1972 Bologna, Italy President: G. Ruggiero

IXth Congress September 12-13, 1980 Brussels, Belgium President: G. Corn61is

XVth Congress September 13-17, 1988 Wtirzburg, Germany President: M. Nadjmi

IVth Congress September 28-29, 1973 Frankfurt, Germany President: H. Hacker

Xth Congress September 25-26, 1981 Milan, Italy President: A. Passerini

Vth Congress September 4 - 6 , 1975 Geilo, Norway President: P. Amundsen

XIth Congress September 15-17, 1983 Berne, Switzerland President: E Huber

XVIth Congress 20th Anniversary of the ESNR July 2 - 6 , 1989 Paris, France President: E. Cabanis

VIth Congress September 16-18, 1976 Dijon, France President: J. Bories

XIIth Congress September 27-29, 1984 Prague, Czechoslovakia President: J. Jirout

Future Meetings XVIIIth Congress of the ESNR September 8-12, 1992 Stockholm, Sweden President: K. Ericson

XIXth Congress of the ESNR September 6 - 1 i, 1993 Bruges, Belgium Presidents: D. Bal6riaux, B. Appel

XVIlth Congress October 8-13, 1991 Zurich, Switzerland President: A. Valavanis

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The European Course in Neuroradiology During its business meeting, held on the occasion of the XIIth Symposium Neuroradiologicum in Washington D.C., USA on October 12, 1982, the General Assembly of the European Society of Neuroradiology on the initiative of Pierre Lasjaunias, created the European Corpse in Neuroradiology (ECNR). The specific objectives and rules of this Course were established during the business meeting of the Society in Berne on September 16th, 1983. The specific objectives of the ECNR are to assemble groups of trainees in the neurosciences, and particularly in neuroradiology, to demonstrate and to discuss the application of basic anatomy and clinical knowledge to the neuroradiology of children and adults. The European Course is organized in cycles, each cycle consisting of three annual courses. The first course of each cycle is devoted to the intracranial nervous system, the second to the skull base and the third to the spine and spinal cord. The ECNR is set up under the direction of the Training Committee of the ESNR.

Past Courses First Cycle

Second Cycle

Third Cycle

First Course

First Course

First Course

Intracranial Nervous System September 9 - t3, 1984, Toulouse Organization: C. Manelfe

Intracranial Nervous System September 2 - 5, 1987, Barcelona Organization: J. Ruscalleda

Intracranial System September 4 - 8, 1990, Milano Organization: G. Scotti

Second Course

Second Course

Second Course

Skull Base September 2 - 5, 1985, Ancona Organization: U. Salvolini

Skull Base August 22-26, 1988, London Organization: B. Kendall

Skull Base July 9-13, t991, Frankfurt Organization: H. Hacker In conjunction with: 1st ESNR Course in Interventional Neuroradiology Organization: J. Moret and A. Valavanis

Third Course

Third Course

Spine and Spinal Cord September 8-11, 1986, Brussels Organization: ]3. Bal6riaux

Spine and Spinal Cord May 7-11, 1989, Lund Organization: S. Cronqvist

Next Course Third Course

Spine and Spinal Cord Corsica, 1992 Organization: Ch. Raybaud

Scientific Award of the European Society of Neuroradiology The Scientific Award for the best one to four original papers presented by young European neuroradiologists during the annual congress of the society was established in 1969 with the foundation of the ESNR and initially awarded in 1970. The Scientific Award of the ESNR is generously sponsored by the Schering Institute. The Award winners include: 1970 C. Manelfe (France) 1971 M. Corrales (Chile) 1972 M. Megret (Switzerland) J. L Merland (France) M. Michotey (France) 1975 I. Moseley (United Kingdom) G. Scialfa (Italy) 1977 D. Lard6 (France) 1982 S. Bockenheimer (Germany) K. Kretzschmar (Germany) P. Lasjaunias (France) t983 R. Aaslid (Norway) J.L. Burguet (France) A. Valavanis (Switzerland) 1985 J. Barckley (United Kingdom) P. Parizel (Belgium) D. Rtifenacht (Switzerland) 1986 A. Beltramo (Italy) J. Chiras (France) M. Mosckin (Sweden)

1987 F. Koschorek (Germany) N. Martin (France) F. Triulzi (Italy) 1988 A. Biondi (Italy) J. Moret (France) P. Parizel (Belgium) G. Schroth (Germany) 1989 C. Debussche (France)

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Honorary Members In 1989 the European Society of Neuroradiology has decided to honor Giovanni Di Chiro, USA T. Hans Newton, USA Juan M. Taveras, USA by conferring upon them an honorary membership of the society. These three American pioneers in neuroradiology have significantly furthered the development of neuroradiology, increased the prestige of the specialty and made important contributions to the scientific and academic life of European institutions.

Neuroradiology Neuroradiology, published by Springer-Verlag, was founded as the official organ of the European Society of Neuroradiology in 1970. The Founding Editors of the journal are: M.M. Schechter, New York (deceased) A. Wackenheim, Strasbourg S. Wende, Mainz (deceased) Since 1981, Neuroradiology is also the official organ of the Japanese Neuroradiological Society.

The Board of Editors-in-Chief

Past Editors-in-Chief

1970-1974

1983-1988

M.M. Schechter, New York A. Wackenheim, Strasbourg S. Wende, Mainz

G. du Boulay (Chairman), London T.P. Naidich, Chicago M. Takahashi, Kumamoto A. Wackenheim, Strasbourg S. Wende, Mainz M.M. Schechter (Emeritus), New York

1974-1980 G. du Boulay, London M.M. Schechter, New York A. Wackenheim, Strasbourg S. Wende, Malnz 1980-1983 G. du Boulay, London T.P. Naidich, Chicago M.M. Schechter, New York A. Wackenheim, Strasbourg S. Wende, Mainz

T.P. Naidich (Chairman), Miami I. Moseley, London M. Takahashi, Kumamoto A. Valavanis, Zurich A. Wackenheim, Strasbourg R.A. Zimmerman, Philadelphia

1988-1991 G. du Boulay (Chairman), London T.P. Naidich, Miami M. Takahashi, Kumamoto A. Valavanis, Zurich A. Wackenheim, Strasbourg S. Wende, Mainz R.A. Zimmerman, Philadelphia

The European Society of Neuroradiology recognizes and thanks

Professor George du Boulay Chairman Emeritus of the Board of Editors-in-Chief for his most significant contribution to the development of the journal. Under his guidance, Neuroradiotogy has become a well-respected publication with a world-wide circulation. The European Society of Neuroradiology recognizes and thanks

Professor Sigurd Wende Editor-in-Chief-Emeritus for his selfless devotion to the journal, particularly during the initial years following its foundation. Without his help and support over the past 20 years, Neuroradiology would not have achieved the standards and recognition it enjoys today. Professor Sigurd W~nde died on July 19, 1991. In recognition of his achievements, the Organizing Committee dedicates this Supplement Volume of Neuroradiology to him.

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First Refresher Course of the European Society of Neuroradiology This year the European Society of Neuroradiology will perform its first Refresher Course. This course has been elaborated following the formidable success of the meanwhile well established European Course in Neuroradiology (ECNR), accepted in its principle in 1982. The purpose of the Refresher Course (RC) is to provide the necessary complement and follow-up to the training course (ECNR) and its therapeutic counterpart (European Course in Interventional Neuroradiology-ECINR) within the frame of the annual scientific meetings of the European Society of Neuroradiology. The objectives of the course are to teach the presently available neuroradiological techniques performed routinely in most centers as well as newer techniques performed in some selected centers. Specifically, the objectives of the Refresher Course are to: 1. 2. 3. 4. 5. 6.

Enhance and increase the clinical and biological background of neuroradiologists Refresh and adapt the anatomic knowledge Update the imaging techniques and diagnostic management of neuroIogic as well as head and neck diseases Inform on the latest development in the areas of interest Homogenize the population of European neuroradiologists, initially trained in their respective countries and lately in the ECNR Create a meeting point and a forum for postgraduate neuroradiologists, regardless of their background.

Nowadays, it seems unconceivable to give a special competence or a specialty accreditation without guarantee that proper update of this knowledge will be directly available. To that extent, large access to formal, postgraduate, refresher courses, abandoning what used to be the privilege of a few individuals, represents a definitive progress. I am personally grateful to the European Society of Neuroradiology and its past presidents (A. Wackenheim, G. du Boulay, S. Cronqvist) as well as its present president (J. P. Braun), who have kept the coherence over the last 10 years and supported the establishment of these three educational units (ECNR, ECINR, ESNR-RC) within the ESNR. This constitutes a gratifying achievement for the "European Savoir faire" in Neuroradiology. None of these projects can be brought forward without help. D. Bai6riaux, O. Flodmark and A. Valavanis have already done a tremendous effort to provide M. Leonardi with the manuscripts for the Course Syllabus to be handed out during the course. For the First Refresher Course, four topics have been selected. The aim was to offer appealing topics for both groups of Neuroradiologists: those primarily interested in the head and neck region and those involved in CNS problems. However, the course being the consequence of the ECNR style, additional conferences will cover: anatomic topics, biological aspects, developmental biol' ogy bases, surgical implications. I hope that all registrants of the Refresher Course will appreciate the efforts of the lecturers and will find in the presentations the necessary information they are looking for, as well as some unpredicted enlighting features that will widen their visions. Pierre Lasjaunias

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Refresher Course ESNR Course A: Venous Disorders of the Brain Chairman: P. Lasjaunias, Paris, France 09.00 a m - 09.45 am

Radioanatomy of the venous system P. Lasjaunias, Paris, France

9.45 a m - i0.30 am

Physiology of the cerebral veins L.M. Auer, Homburg, Germany

10.30 a m - 11.00 am

Coffee Break

11.00 a m - 11.45 am

Coagulation disorders and cerebral venous thrombosis C. Boyer, Paris, France

11.45 a m - i2.30 pm

Neuroradiological aspects of cerebral venous diseases W. Wichmann, Zurich, Switzerland

12.30 p m - 02.00 pm

Lunch - Seminar

Refresher Course ESNR Course B: Cranial Base Extension of Nasopharyngeal Tumors Chairman: A. Valavanis, Zurich, Switzerland 09.00 am-09.45 am

The anatomy of the nasopharynx and of the related skull base S. Kubik, Zurich, Switzerland

09.45 a m - 10.30 am

Pathology of nasopharyngeal tumors M. Makek, Zurich, Switzerland

10.30 a m - 11.00 am

Coffee Break

11.00 a m - 11.45 am

Diagnostic and therapeutic neuroradiology of nasopharyngeal tumors A. Valavanis, Zurich, Switzerland

11.45 a m - 12.30 pm

Clinical presentation and microsurgical management of nasopharyngeal tumors extending into the skull base U. Fisch, Zurich, Switzerland

i2.30 pm-02.00 pm

Lunch - Seminar

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Refresher Course ESNR Course C: Cervical Spine Chairman: D. Bal6riaux, Brussels, Belgium

02.00 pm-02.45 pm

Biomechanics: Present concepts J. Wilmink, Groningen, Netherlands

02.45 p m - 03.30 pm

The torticollis J. E Bonneville, Besangon, France

03.30 pm-04.00 pm

Coffee Break

04.00 pm-04.45 pm

Acute cervical myelopathy S. Holffts, Lund, Sweden

04.45 p m - 05.30 pm

Multicentric report on present management of cervicarthrotic myelopathy D. Bal6riaux, Brussels, Belgium C. Manelfe, Toulouse, France J.L. Dietemann, D. Krause, Strasbourg, France

Refresher Course ESNR Course D: Congenital anomalies of the anterior cranial base Chairman: O. Flodmark, Stockholm, Sweden

02.00 p m - 02.45 pm

Normal and abnormal developmental biology of the anterior cranial base G. Couly, Paris, France

02.45 pm-03.30 pm

Neuroradiological aspects of the anterior cranial base malformations O. Flodmark, Stockholm, Sweden

03.30 pm-04.00 pm

Coffee Break

04.00 pm-04.45 pm

3 D-reconstruction and prospective imaging aspects E. Cabanis, D. Hemmy, Paris, France/Milwaukee, USA

04.45 pm-05.30 pm

Therapeutic aspects of anterior cranial base malformations D. Renier, Paris, France

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Course A: Venous Disorders of the Brain This course moderated by P. Lasjaunias will cover all aspects of the venous anatomy and pathology of the brain. P. Lasjaunia~s will give a comprehensive update on the radio-anatomy of the venous system and provide new concepts explaining the transition from the venous anomaly to the venous malformation. L.M. Auer will give an update on the physiological aspects of the cerebral veins. C. Boyer will provide an in depth discussion and modern concepts of the coagulation disorders and of the cerebral venous thrombosis. The neuroradiological aspects of cerebral venous diseases as well as the relative role of non-invasive and invasive imaging techniques will be discussed by W. Wichmann. By the use of invasive (arteriography, phlebography) and non-invasive methods (CT, MRI, US) modern neuroradiology is nowadays able to explore both the anatomy and the pathology of the cerebral venous system. The venous pathology of the brain includes multiple disease entities. Telangiectasias: These are small capillary malformations and are mainly discovered by the pathologist. The venous component of arteriovenous malformations (AVM) has been neglected for a long time but is now recognized to be of major importance for understanding and explaining both hemorrhagic and non-hemorrhagic neurological symptomatology. The precise cartography of the venous drainage of the AVM and an understanding of the drainage of the surrounding brain tissue is provided by selective and superselective endovascutar approaches. In addition, MRI provides additional information on the morphology of the surrounding brain tissue. MR-angiography seems to represent an interesting step in the evaluation of these lesions. Developmental venous anomalies (DVA, so-called venous angiomas) can not be considered as malformations: they represent a form of variability of the venous drainage where medullary veins, ending in a transcerebral collector, try to com-

pensate by their disposal and hypertrophy a thrombosis or agenesis of a part of the venous system, that occurred in utero. Angiography provides typical images of the DVA, but is not anymore mandatory since CT and MRI can easily detect these anomalies. Cavernomas represent true venous malformations. They may be located anywhere in the central nervous system, can be multiple and may have a familial occurrence. Their symptomatology is variable, including hemorrhagic episodes or neurological symptoms. However, most of them remain clinically silent. MRI is the best method for diagnosis showing typical mosaic-like patterns formed by hypo- and hyperintensities corresponding to the various states of blood (slow flowing, acute and chronic thrombosis, hemorrhages), within the malformation. lntracranial tumors mainly displace deep or superficial venous structures, or obstruct dural sinuses. Intratumoral arteriovenous shunts lead to early venous drainage, especially in glioblastoma multiforme. Non-invasive methods are nowadays prefered for the diagnosis of these lesions. Cerebral sinus thrombosis is a disease difficult to diagnose clinically, because of the great variability of symptoms that may be encountered. Cerebral sinus thrombosis may be of septic or non-septic origin. Angiography provides a direct image of the clot within the sinus and allows assessment of the involved cortical veins. However, CT and especially MRI provide precisely the direct and indirect signs of sinus thrombosis. The later methods also represent excellent non-invasive techniques for follow-up. Venous infarctions are caused by cerebral venous thrombosis as well as by dural arteriovenous fistulae with cortical venous drainage. These infarctions may be hemorrhagic or non-hemorrhagic. Non-invasive techniques and preferentially MRI are applied for the examination of this pathology and for treatment planning.

Course B: Cranial Base Extension of Nasopharyngeal Tumors This course, moderated by A. Valavanis, will provide an update on the anatomy of the nasopharynx and of the related skull base (S. Kubik), on the pathology of the nasopharyngeal tumors (M. Makek), on the diagnostic and therapeutic neuroradiological aspects of nasopharyngeal tumors as well as the pathways of their intracranial extension (A. Valavanis) and on the clinical presentation and microsurgical management of nasopharyngeal tumors extending into the skull base (U. Fisch). Tumors originating from the nasopharynx and the surrounding spaces may extend intracranially through the skull base. Non-invasive neuroradiological techniques (CT, MRI) are performed in order to investigate not only the neoplastic condition itself but also its patterns of propagation: transforaminal extension, direct bone destruction and infiltration, perineural tumor spread, extension along the adventitia of the internal carotid artery. Although CT offers a precise delineation of bony structures, contrast-enhanced MRI visualizes the tumor itself, estimates the size and topography of the intracranial portion

and allows differentiation between extra- and intradural tumor extension. Perineurai spread consists of invasion of peri- and endoneural spaces without involvement of the axons. This represents a common route of tumor extension, mainly through the foramen ovale into the intracranial space along the inferior branch of the trigeminal nerve (V 3). MRI is superior to CT in detecting perineural tumor extension through foramen ovale by showing enlargement of the nerve diameter, widening of the foramen ovale and involvement of the trigeminal cistern and of the cavernous sinus. An indirect but reliable sign is secondary atrophy of the ipsilateral muscles of mastication. This type of extension is encountered in masticator space tumors, parapharyngeal space tumors and nasopharyngeal tumors. Angiography should be performed in cases of hypervascular tumors in order to assess the vascular architecture of the lesion and to perform preoperative embolization (mainly by microparticles). Embolization is usually performed during diagnostic angiography and after superselective catheterization of all

S 92 feeding branches to the tumor. Internal carotid artery branches may supply the tumor, but this does not obligatorily signify, that there is intracranial extension. Correlation of the angiographic picture with CT and MRI helps to estimate precisely the tumor localization. If superselective approach to

these internal carotid artery branches is not possible with microcatheters, transient or permanent occlusion of the internal carotid artery with detachable balloons may be considered, the later performed under strict management and monitoring.

Course C: Cervical Spine This course, moderated by D. Bal6riaux, will address present conce~s of the biomechanics of the cervical spine (J. Wilmink), the complex issue of torticollis (J.F. Bonneville), the neuroradiol0gical aspects of acute cervical myelopathy (S. Holt,s) and will provide a multicentric report on the present management of cervicarthrotic myelopathy (D. Bal6riaux, 13. Krause, C. Manelfe and J.L. Dietemann). Acute cervical myelopathy has several causes, ranging from trauma to immune reactions or to a disease located elsewhere in the body. Nowadays, MRI allows a precise diagnosis of the lesions. The MRI-examination is guided by the clinical signs encountered: spinal block, spinal cord infarction, Brown-S6quard syndrome, Lhermitte syndrome, Guillain-Barr6 syndrome.

Acute transverse myelopathy occurs at any age and is characterized by an acutely developing ascending or static spinal cord dysfunction affecting both halves of the cord. The etiology can be variable (infarct, myelitis, hematoma, abscess, disk herniation). The outcome is often pure with permanent damage to the cord.

In spinal epidural abscess the infection is often due to a hematogeneous spread of bacteria (most often staphylococcus aureus), either directly into the epidural space or as a secondary extension from vertebral bodies or disks. Compression of the cord will produce clinical signs. In multiple sclerosis the lesions are mainly located in the posterior columns of the cord. MRI is of great value because it

provides direct detection of the plaque. However, these images being unspecific, the clinical and paraclinical data have to be taken into consideration and the examination has usually to be extended to the brain in order to detect concommitant lesions that would support the diagnosis of MS.

Traumatism may cause injury to the cord directly or indirectly through associated lesions (bony fragments, disk herniation, epidural hematoma, etc.). CT and MRI are applied in order to extract the most complete information about the lesional status. Arteriovenous malformations may produce intramedullary and subarachnoid hemorrhage that cause various degrees of acute myelopathy. MRI will disclose hematomas and abnormal vessels.

Spinal epidural hematoma is usually spontaneous or associated to minimal traumatism.

Tumors, especially extradural metastases, may be responsible for subacute or acute myelopathies. The most frequent localization is the throracic spine. Pathological fractures may also cause severe lesions because of the spinal instabilities they produce. Disk herniations most often affect middle aged patients. When they are located posteriorly or posterolaterally they may cause acute cervical myelopathy.

Rheumatoid arthritis causes C 1 - C 2

instability, vertical dislocation and luxations. Myelopathy produced by rheumatoid arthritis may have an acute or subacute onset.

Course D: Congenital Anomalies of the Anterior Cranial Base This course moderated by O. Flodmark will address the spectrum of congenital anomalies of the anterior cranial base, featuring the normal and abnormal developmental biology of the anterior cranial base (G. Couly), the neuroradiological aspects of the anterior cranial base malformations (O. Flodmark), the application of 3-D-reconstructions and prospective imaging techniques for the diagnosis of congenital anomalies of the anterior cranial base (E. Cabanis, D. Hemmy) and will discuss the therapeutic aspects of the anterior cranial base malformations (D. Rennier). Malformations of the anterior cranial base are rare lesions. They include premature fusion of cranial sutures, holoprosencephaly and cranial dysraphism (encephaloceles, nasal dermoid cysts, etc.). Although plain skull X-ray films and CT (including three-dimensional reconstructions) are important examinations

for the study of the bone malformations, MRI offers an excellent delineation of the associated brain anomalies.

Premature fusion of the cranial sutures affects the size and aspect of the skull. When it involves the anterior cranial base it is limited to coronal and metopic suture synostosis. This primary cranio-synostosis may be associated with congenital syndromes such as Apert's diseases and Crouzon's diseases.

Holoprosencephaly is a cleavage defect of the prosencephalon, associated with agenesis or incomplete formation of the lateral hemispheres. This results in malformations of the anterior base and face. Cyclopia, ethmocephaly and cobocephaly are severe malformations which are incompatible with life. Milder forms, which are compatible with life, include premaxiUary agenesis with cleft lip and hypotelorism.

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Craniofacial dysraphism is a congenital malformation involving the mid-face and the anterior base of the skull. It may comprise several entities: Cephalocetes are lesions with a defect in the cranium and dura through which intracranial structures herniate. This entity may be classified into meningo- or encephaloceles. Their etiology is unknown and their clinical symptomatology depends on the location of the malformation (sphenoidal, fronto-ethmoidal, naso-ethmoidal, naso-orbital, naso-frontal, interfrontal).

Median cleft face syndromes are rare and are always associated with hypertelorism. In the mildest form of the disease, these patients do not have associated intracranial abnormalities and usually have normal intelligence without neurological deficits.

Nasal dermal sinuses (also called dermal cyst, dermoid cyst, dermoid or nasal-dermoid sinus cyst) involve the floor of the anterior cranial fossa. They originate from remnants of an embryonic connection to the dura in the region of the falx cerebri. In nearly every case an intracranial extension of the cyst is found.

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Scientific Session

Scientific Session: Epilepsy, Brain Malformations Moderators: G. du Boulay, London, United Kingdom and O. Flodmark, Stockholm, Sweden 08.30 a m - 09.00 am

Invited Lecture: MR Imaging of Brain Surface Anatomy T. R Naidich, Miami, USA

09.00 a m - 10.00 am

Scientific Papers 6 3 - 69

10.00 a m - 10.20 am

Coffee Break

09.00 am-lO.O0 am Scientific Papers 63-69 063 MRI and CT: Relative accuracy in evaluation of seizure disorder in pediatric age group M.A. Mikhael, Evanston, USA 064 Magnetic resonance diagnosis of mesial temporal sclerosis M. Bracchi, M. Casazza, R. Spreafico, M.A. Vaghi, Milano/Torino, Italy 065

Is Gadolinium helpful for screening MRI in partial complex epilepsy? W.P. Sanders, G. Barkley, E.M. Spickler, R. Silbergleit, Detroit, USA

066 Temporal lobe surgery in partial epilepsy: MRI in postoperative control B. Ostertun, C. Cedzich, L. Solymosi, M. Reiser, Bonn, Germany

067 Diagnosis of cerebral malformations with MRI and real time sonography D. Wimberger, G. Zoder, G. Bernert, L. Prayer, E. Schindler, H. Imhof, Vienna, Austria 068 MRI of cavernous sinus subarachnoid diverticulum G.C. Dooms, P. Mathurin, G. Corn61is, Brussels, Belgium 069 Craniosynostosis E. Donauer, C. Faubert, M. Bernardi, D. Neuenfeldt, Homburg/Saar, Germany

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Invited Lecture:

MR Imaging of Brain Surface Anatomy T.P. Naidich Baptist Hospital of Miami, Miami, Florida, USA Magnetic resonance imaging 'displays all the gross anatomy of the brain. Those seeking to interpret these images must be thoroughly familiar with that anatomy in order to use this new modality to best advantage. I. Surface features

The frontal lobe occupies the anterior portion of the cerebrum above the lateral (sylvian) fissure and anterior to the central sulcus. It has 3 surfaces: lateral, inferior and medial. The lateral surface of the frontal lobe has (a) 3 longitudinal gyri, the superior, middle and inferior frontal gyri, separated by the superior and inferior frontal sulci and (b) one transverse gyrus, the precentral gyrus. The inferior frontal gyrus assumes a triangular shape. The precentral gyrus is oriented approximately vertically along the anterior margin of the central sulcus, between the precentral sulcus anteriorly and the central sulcus posteriorly. The inferior surface displays the gyrus rectus between the interhemispheric fissure and the olfactory sulcus and multiple orbital gyri lateral to the olfactory sulcus. The orbital gyri are usually oriented around an H-shaped orbital sulcus as follows: 1

2

4

3 where 1 = medial orbital gyms, 2 = anterior orbital gyms, 3 = posterior orbital gyrus and 4 = lateral orbital gyrus. The medial surface of the frontal lobe presents the gyrus rectus inferiorly, the parolfactory area slightly higher up and the cingulate gyrus surrounding the corpus callosum. On the medial surface of the frontal lobe, superficial to the cingulate gyrus and sulcus, lie the medial surface of the superior frontal gyrus and the paracentral lobule. The paracentral lobule usually spans the medial end of the central sulcus and therefore contains both the posteromediaI frontal lobe and the adjacent medial parietal lobe. The pars marginalis of the cingulate sulcus delimits the posterior margin of the paracentral lobule. The temporal lobe occupies the anterior portion of the cerebrum below the lateral fissure and anterior to the parietooccipital sulcus. It has 3 surfaces: lateral, inferomedial and superior. The lateral surface of the temporal lobe has 3 longitudinal gyri, the superior, middle and inferior temporal gyri separated by the superior and inferior temporal sulci. The inferior temporal gyrus curves onto the inferomedial surface of temporal lobe. On the inferomedial surface of temporal lobe, from lateral to medial, lie the inferior temporal gyrus, the lateral occipitotemporal (fusiform) gyrus, the medial occipitotemporal (lingual) gyrus [in posterior half of temporal lobe only] and the parahippocampal gyrus. The posterior end of the parahippocampal gyrus curves around the splenium to become the cingulate gyrus. The portion of this continuous gyrus that is situated just behind and below the splenium is designaged the isthmus of the cingulate gyrus. The anterior end of the parahippocampal gyrus recurves medially and caudally to form the uncus. Just above the parahippocampal gyrus lies the convoluted

hippocampal formation (see below). The superior surface of the temporal lobe is characterized by the transverse temporal gyrus of Heschl and the planum temporale behind it. The parietal lobe lies posterior to the central sulcus, anterior to the parietooccipital sulcus and superior to the lateral fissure. It has two surfaces: lateral and medial. The lateral surface has 1 transverse gyrus, the postcentral gyms. This forms the posterior border of the central sulcus and is bounded posteriorly by the postcentral sulcus. Behind the postcentral gyrus lie two longitudinal gyri, the superior parietal lobule above the interparietal sulcus and the inferior parietal lobule below that sulcus. There are also 3 U-shaped gyri, the supramarginal gyrus that caps the top of the lateral fissure, the angular gyrus that caps the top of the superior temporal sulcus and the parieto-occipital arcus that caps the top of the parietooccipital sulcus. On the medial surface just behind the paracentral lobule is the precuneus. Inferior to this is the cingulate gyrus. The occipital lobe is the posterior portion of the cerebrum situated behind the parietooccipital sulcus and preoccipital notch. It has a lateral and medial surface. On the lateral surface lie the parietooccipital arcus above the transverse occipital suicus and the variable lateral occipital gyri arranged about the lateral occipital sulcus. On the medial surface lie the cuneus above the calcarine sulcus, the medial occipital temporal (lingual) gyrus below the calcarine sutcus and the lateral occipitotemporal (fusiform) gyrus below the collateral sulcus. The major anatomic features of the low-mid convexity, fronto-parietal operculum are the sylvian fissure, six major gyri and six major suM: Gyri 1. Middle Frontal Gyrus 2. Inferior Frontal Gyrus 3. Precentral Gyrus 4. Postcentral Gyrus 5. Supramarginal Gyrus 6. Angular Gyrus

Sulci 1. Superior Frontal Sulcus 2. Inferior Frontal Sulcus 3. Precentral Sulcus 4. Central Sulcus 5. Postcentral Sulcus 6._Superior Temporal Sulcus. Two additional small sulci - the anterior and posterior subcentral sulci - complete the anatomic features necessary for identification of anatomy along the low-mid convexity. Diagram 1 from reference 13 depicts the major anatomic relationships among these features. In brief, the sylvian fissure has three major rami and two short sulci. The horizontal ramus and ascending ramus subdivide the triangular inferior frontal gyrus into three parts, the pars orbitalis that abuts the orbital gyri, the pars triangularis that lies between the horizontal and ascending rami, and the pars opercularis that lies behind the ascending ramus and forms the most anterior portion of the frontal operculum. The middle frontal gyrus lies superior to the inferior frontal gyrus and is separated from it by the inferior frontal sulcus. This sulcus courses atop the pars triangularis of the inferior frontal gyrus. The superior frontal gyrus lies superior to the middle frontal gyrus, from which it is separated by the superior frontal sulcus.

S 96 Diagram 1 1 Inferior frontal gyrus 1' pars orbitalis 1" pars triangularis 1" pars opercularis 2 Middle frontal gyrus 3 Superior frontal gyrus 4 Preeentral gyrus 5 Postcentral gyrus 6 Supramarginal gyrus 7 Angular gyrus

a b c c' d e f g *

Superior frontal sulcus Inferior frontal sulcus Inferior precentral sulcus Superior precentral sulcus Central sulcus Postcentral sulcus Sylvian fissure Superior temporal sulcus Fusion between middle frontal gyrus (2) and precentral gyrus (4)

From: Naidich TP, Valavanis AG, Kubik S: Inferior frontal landmarks for identifying the precentral and postcentral gyri along the low convexity on sagittal MRI. Presented at the 29th Annual Meeting of the American Society of Neuroradiology, June 9-14, 1991, Washington D.C.

The precentral, central and postcentral gyri form three roughly "parallel" or zig-zag sulci that course obliquely from antero-inferior to postero-superior. The precentral gyrus and postcentral gyrus course between these sulci anterior and posterior to the central sulcus. The middle frontal gyrus characteristically merges with the anterior surface of the precentral gyrus. The pre- and postcentral gyri characteristically merge with each other immediately above the sylvian fissure. The anterior subcentral sutcus indents the inferior end of the precentral gyrus. The posterior subcentral sulcus indents the inferior end of the postcentral gyrus. Consequently each gyrus appears slightly bifid or splay-footed. The precentral sulcus is formed by two discontinuous grooves called the inferior precentral sulcus and the superior precentral sulcus. The upper end of the inferior precentral sulcus lies anterior to the lower end of the superior precentral sulcus. The gap in the precentral sulcus occurs at the point where the middle frontal gyrus fuses with the precentral gyrus. The inferior frontal sulcus intersects and helps to identify the inferior precentral sulcus. The superior frontal sulcus intersects and helps to identify the superior precentral sulcus. The central sulcus courses approximately parallel to the zigzag precentral sulcus. The central sulcus (almost) never intersects the sylvian fissure. Rather, the bottom end of the central sulcus is closed by the fusion of the pre- and postcentral gyri. The postcentrai gyrus courses roughly parallel to the central sulcus between the postcentral gyrus and the supramarginal gyrus. The supramarginal gyrus forms a horseshoe-shaped gyrus (open inferiorly) that is draped over the superior end of the posterior ramus of the sylvian fissure. The angular gyrus similarly forms a horseshoe gyrus draped over the upper end of the superior temporal sulcus. One may then identify the gyri and sulci along the low-mid convexity simply by identifying the triangular shape of the inferior frontal gyrus containing the horizontal and ascending rami of the sylvian fissure, the inferior frontal sulcus atop the pars triangularis of the inferior frontal gyrus, the termination of the inferior frontal sulcus in the inferior precentral sulcus, union of the middle frontal gyrus with the precentral gyrus at the discontinuity in the precentral sulcus, the precentral gyrus behind the precentral sulcus, the central sulcus closed off from the sylvian fissure by the union of the pre- and postcentral gyri, the postcentral gyrus with characteristic splay-foot about the

posterior subcentral sulcus, the postcentral sulcus between the postcentral gyrus and the supramarginal gyrus, and, finally, the supramarginal gyrus draped over the posterior ramus of the sylvian fissure. Multiple studies in patients and in anatomical material have shown that there are reproducible asymmetries in the surface features of the two hemispheres which appear to be related to the side of cerebral functional dominance. Most individuals are naturally fight-handed with left cerebral dominance In these individuals the left planum temporale is substantially larger than the right. In right-handed individuals, the left parietal lobe is larger than the right so that (compared to the right) the left sylvian fissure is slightly lower, extends slightly further posteriorly and has a more nearly horizontal than inclined course. As a consequence, on coronal angiograms the sylvian vessels that pass over the insula and then under the larger left parietal opereulum form a sharper, narrower angle where they recurve from the insula onto the overhanging operculum. The Vein of Labb6 tends to be the prominent superficial vein on the dominant side whereas the Vein of Trolard tends to be the prominent superficial vein on the non-dominant side. The two cerebral hemispheres display an asymmetry of position with respect to each other, such that, seen from above, the nondominant right hemisphere appears to rotate anteromedially ahead of the left while the dominant left hemisphere appears to rotate posteromedially behind the right. As a consequence, the right frontal pole projects ahead of the left. This is called right frontal petalia (petalia from the word centripetal). The left occipital pole projects posterior to the right. This is designated left occipital petalia. The dural and calvarial envelopes that condense around the brain demonstrate the same asymmetries related to the petalias. That is, the falx contained within the interhemispheric fissure deviates to the right posteriorly and the tentorial leaf within the left cerebro-cerebellar fissure inserts further inferiorly to accommodate the larger, petatic left posterior hemisphere. The contours of the cranial vault match the petalias, especially the impressions along their inner tables. Phylogenetically these asymmetries seem to be present in apes (e.g. orangutan) and in homo neanderthalis (as judged from cas~s of the endocranial space showing the expected petalias). Embryologically it would appear that the right

S 97 hemisphere develops its sulci and fissures earlier than the left. These asymmetries of sulci and petalia become apparent as early as the fourth month of gestation. II. Deep gray nuclei The deep gray nuclei are all the masses of gray matter buried deep to the cortex. These are divided into the thalamus and the basal ganglia. The basal ganglia include the caudate nucleus, the lentiform nucleus (composed of globus palidus and putamen), the claustrum and the amygdala. The globus pallidus is further subdivided into lateral and medial nuclei, so the lentiform nucleus has three parts (from lateral to medial): the putamen, lateral nucleus of globus pallidus and medial nucleus of globus pallidus. The term corpus striatum is sometimes used to identify the caudate nucleus plus the lentiform nucleus. It is so named because caudatolenficular bridges of gray matter connect the caudate and lentiform nuclei across the intervening internal capsule, causing a striped, striated appearance. The deep gray nuclei form much of the lateral walls of the ventricles. The head of caudate nucleus forms the inferolateral wall of the frontal horn. The body of caudate nucleus forms the superolateml portion of the floor of the body of the lateral ventricle. The tail of caudate nucleus forms part of the roof of the temporal horn. The thalamus and hypothalamus form the lateral walls of the third ventricle. The thalamus also forms the floor of the lateral ventricle medially. The amygdala forms the anterior wall of temporal horn. Embryologically, all the deep gray nuclei start as one ganglial eminence. They then become partially subdivided by the invasion of the internal capsule and overgrowth of the cerebrum with consequent migration of the temporal lobe "down and around". However, the ganglia still remain attached in many ways. Thus the caudate and putamen are attached to each other inferomedial to the anterior limb of internal capsule. This zone o f attachment is the nucleus accumbens septi. The amygdala is attached superiorly to the putamen and claustrum and caudally to the tail of caudate nucleus. The caudate nucleus and the lentiform nucleus lie at an oblique angle to each other. They are farther apart posteriorly than anteriorly, superiorly than inferiorly and laterally than medially. Thus the intervening internal capsule is narrowest anteroinferomedially. In coronal section, the anterior limb appears as a wedge of white matter situated between the head of caudate nucleus and the lentiform nucleus. It is widest superolaterally. The gray matter of the two nuclei is continuous inferomedial to the anterior limb as the nucleus accumbens septi. The genu appears as a curvilinear crescent that is concave inferolaterally over the lentiform nucleus. The genu separates the anterior pole of thalamus medially from the lentiform nucleus laterally. The posterior limb is wider than the anterior limb and is of uniform thickness (not wedge-shaped). It is concave medially around the thalamus and separates the thalamus medially from the lentiform nucleus laterally. The retrolenticular and sub-lenticular portions of internal capsule lie behind, and below, the lentiform nucleus. The claustrum forms a shell-like structure between the external and extreme capsules. It is concave medially, co-curvilinear with the insula, and may be regarded as a detached medial segment of the insula. In axial section, the head of caudate nucleus forms the lateral border of the frontal horn and gives it its characteristic shape. The thalamus forms the lateral border o f the third ventricle. The thalamus is narrow anteriorly where it forms the lateral border of the foramen of Monro and wide at the pulvinar

posteriorly where it forms the anterior wall of the atrium. Its medial border is flat and parallel to the midline third ventricle, whereas its lateral border is convex and oriented at an oblique to the midline~ The internal capsule appears as a chevronshaped band of white matter which is thinner anteriorly and thicker posteriorly. The lentiform nucleus lies in the wide laterally-open angle of the chevron. Because of the oblique lateral border of the thalamus, the posterior limb of internal capsule and the lentiform nucleus also lie at an oblique to the midline. As a result, any sagittal section through the lentiform nucleus, internal capsule and thalamus is constrained to pass through these structures in fixed order from anterior to posterior. If it passes through the lentiform nucleus it must do so in order from putamen to lateral nucleus of globus pallidus to medial nucleus of globus pallidus. If it passes through thalamus it must intersect first the lateral surface of thalamus and only later the medial-posterior surfaces. In sagittal sections the internal capsule assumes several different shapes, depending on the plane. A plane through the genu will display the internal capsule as a greek letter r/where the anterior arm is the anterior limb, the stem is the genu ending inferiorly in the cerebral peduncle and the posterior arm is the posterior limb. Further laterally, in sections through the anterior and posterior limbs lateral to the genu, the anterior limb is thin, hard to see and best discerned as striations of the alternating fascicles of internal capsule and caudatolenticular bridges of gray. The posterior limb forms a sickle shape concave anteriorly. Yet further laterally, the sickle becomes thinner, lies behind the lentiform nucleus and is formed by the retrolenticular and sublenticular portions o f the internal capsule. III. Anterior commissure The anterior commissure is a useful landmark for locating the lateral and medial nuclei of globus pallidus. In axial vie~; the anterior commissure has the shape of bicycle handlebars. It crosses the midline in the anterior wall of the third ventricle, just anterior to the anterior columns of the fornix. It then courses anteroinferolaterally just behind the head of caudate nucleus and the tapering inferomedial edge of the anterior limb of internal capsule. It passes into the lateral nucleus of globus pallidus where it makes a genu and then passes posteroinferolaterally under claustrum, over amygdala and over anterior temporal horn into the inferior and middle temporal gyri. In midsaglttal sections, the anterior commissure appears as an ovoid, white matter structure that indents the lamina terminalis of the anterior wall of the third ventricle just inferior to the foramen of Monro. Further laterally, where it passes under the anterior limb o f internal capsule, the anterior commissure forms a tear-drop at the bottom of the anterior arm of the r/. Further laterally, the anterior commissure forms a ovoid within the inferior portion of the lateral nucleus of globus pallidus. Since the anterior commisssure is easy to identify, it provides the best landmark for localizing the lateral nucleus of globus pallidus in saglttal section. The lateral nucleus of globus pallidus lies just above the anterior commissure. The medial nucleus o f globus pallidus lies immediately behind the lateral nucleus, just in front of the genu o f internal capsule. IV. The Hippocampai formation and limbic lobe For histologlc and (?) functional reasons, it seems reasonable to distinguish a primitive portion of the brain as the limbic lobe. This consist of the encircling parahippocampal-cingulate gyms and the hippocampal formation. These can now be demonstrat-

S 98 ed readily by MR. To understand this anatomy we must build up a series of layers around the corpus callosum. As seen in lateral view, the parahippocampal gyrus passes posteriorly, arcs behind the splenium and then continues anteriorly above the corpus callosum as the cingulate gyrus. The cingulate gyrus continues around the genu to become the subcallosal (parolfactory) area. The entire system is one tong gyrus. The portion of the gyrus directly behind and below the splenium is designated the isthmus of the cingulate gyrus. Therefore, from temporal lobe around corpus callosum to frontal lobe the parahippocampal gyrus becomes isthmus, becomes cingulate gyrus, becomes subcaUosal area. Just superior to the parahippocampal gyrus is a long fissure - the hippocampal fissure. This courses posteriorly, curves around the splenium anterior to the isthmus and continues anteriorly as the callosal sulcus, inferior to the cingulate gyrus. This entire fissure is one long cleft; the hippocampal fissure simply becomes the callosal sulcus. In the temporal lobe, a thin dentate gyrus lies above the hippocampal fissure, arcs around the splenium anterior to the fissure, and becomes the vestigial supracallosal gyrus 0ndusium griseum plus medial and lateral longitudinal striae) below the callosal sulcus, closely applied to the corpus callosum. The portion of this gyrus just behind and below the splenium is designated the fasciolar gyrus. The portion of this gyrus that continues anterior to the rostrum of corpus callosum is designated the paraterminal gyrus. Thus, the entire gyrus is one long strip called dentate gyrus in the temporal lobe, becoming fasciolar gyrus behind the splenium, supra-callosal gyrus above the corpus callosum and paraterminal gyrus anterior to the rostrum. With that as background, the relationships of the hippocampal formation may now be understood best in coronal plane. The parahippocampal gyrus forms the medial surface of the temporal lobe. The medial and superior surfaces of the gyrus consist of a specialized cortex designated the subiculum. The curvature of the subiculum arcs superiorly and then laterally into the hippocampal fissure. The lower bank of the fissure is the dentate gyrus. At the lateral border of the fissure a Cshaped roll of tissue - the hippocampus - caps the lateral end of the fissure and bulges into the temporal horn. The white fibers of the subiculum pass laterally to the subependymal surface where they form a+thin white lamina called the alveus. The alveus is situated between the ependyma and the hippocampus. The alveal fibers then arc medially over the hippocampus and dentate gyrus and detach from the dentate gyrus along the dentatofimbrial fissure to form the fimbria. The fimbria is a thin band of white matter that projects as a free margin into the basal cistern. The fimbria plus the alveus together constitute the fornix. The fornix passes posteriorly, arcs around the thalamus, under the splenium and attaches to the undersurface of the corpus callosum as the crus of fornix. The crus of fornix makes up the inferomedial wall of the atrium and of the body of the lateral ventricle. The two crura of each side crosslink through the commissure of the fornices. The crura merge anteriorly into a single body and then redivide into two anterior column of the foramina of Monro. They pass inferiorly, behind the anterior commissure toward the anterior nucleus of the thalamus and the mammillary bodies. V. Brainstem

The typical surface contours of the brainstem are easily displayed by MR. The positions and courses of larger, 3rd, 5th, 7th and 8th cranial nerves are easily delineated. The cranial and extracranial courses of these nerves may be shown in some

cases. However, small cranial nerves, 4, 6, and 9 - 1 2 are poorly shown. Serial proton density images readily display significant fiber tract systems within the brainstem, such as the descending tracts in the cerebral peduncle, their stereospecific break-up into smaller fascicles in the pons, and formation of the pyramids of the medulla. Similarly, serial proton density images readily display the ascending course of afferent fibers from the gracile and medial cuneate nuclei to the internal arcuate fibers that then decussate and ascend as the medial lemnisci to the posterolateral ventral nucleus, the posterior group, the magnocellular part of the medial geniculate body and the zona incerta. The median longitudinal fasciculus and the lateral lemnisci may also be imaged successfully. VI. Cerebellum

The cerebellum is divided into 3 lobes of unequal size: anterior, posterior and flocculonodular. The primary fissure separates the anterior lobe from the posterior lobe. The posterolateral fissure separates the posterior lobe from the flocculonodular lobe. These lobes are further divided into unequal vermian and hemispheric lobules by smaller fissures. In general, each vermian lobule is continued laterally into a hemispheric lobule. However, exceptions exist: (1) the lingula has no hemispheric counterpart; (2) the tuber has two hemispheric counterparts, the inferior semilunar and the gracile lobules; (3) between the great horizontal fissure and the secondary fissure, there are two vermian and 3 hemispheric lobules which align imprecisely. Within this zone, the prepyramidal fissure, confined to the vermis, separates the two vermian lobules. The inferior posterior fissure and the inferior anterior fissure, both confined to the hemispheres, separate the 3 hemispheric lobules. The fourth ventricle lies within the center of the cerebellum, surrounded by brain stem anteriorly, vermis and tonsils posterosuperiorly, the cerebellar peduncles laterally and the central white matter (corpora medullaria) with their contained "roof nuclei" posterolaterally. The anterior wall of the fourth ventricle is formed by the anterior medullary velum. The lingula is very closely applied to this. The posterior wall of the fourth ventricle is formed by the posterior medullary velum. The nodulus (in the midline) and the superior poles of the two tonsils (paramedian) are closely applied to this. The posterolateral fissure separates the nodulus from the uvula and the tonsils from the posterior medullary velum. From the central white corpora medullare, the 3 cerebellar peduncles pass to brain stem: logically, the inferior cerebellar peduncle (restiform body) passes to the medulla, the middle cerebellar peduncle (brachium pontis) passes to the pons and the superior cerebellar peduncle (brachium conjunctivum) passes to the midbrain. The brachium pontis is the largest of these three. The roof nuclei are oriented as bilateral pairs. From medial to lateral there are the fastigial, globus, emboliform and dentate nuclei. With this brief understanding of anatomy, it becomes possible to use the magnetic resonance images to display normal structures and pathologic displacements of these structures easily. References

Atlas SW, Zimmerman RA, Bilaniuk LT, Rorke L, Hackney DB, Goldberg HI, Grossman RI (1986) Corpus callosum and limbic

S 99 system: Neuroanatomic MR evaluation of developmental anomalies. Radiology 160:355-362 Bergvall B, Rumeau C, Van Bunnen Y, Corbaz JM, Morel M (1988) External references of the bicommissural plane. In: Gouaze A., Salamon G (eds) Brain Anatomy and Magnetic Resonance Imaging. pp 2-10. Springer-Verlag, Berlin Chi JG, Dooling EC, Giles FH (1977) Gyral development of the human brain. Annals of Neurology 1:86-93 Courchesne E, Press GA, Murakami J, Berthoty D, Grafe M, Wiley CA, Hesselink JR (1989) Cerebellum in sagittal plane - anatomic MR correlation: I. The vermis. AJNR 10:659 Daniels DL, Haughton VM, Naidich TP (i987) Cranial and Spinal Magnetic Resonance Imaging. An Atlas and Guide. Raven Press, New York Drayer BP, Burger P, Darwin R, Riederer S, Herfkens R, Johnson GA (1986) Magnetic resonance imaging of brain iron. AJNR 7:373 - 380 Flannigan BD, Bradley WG Jr, Mazziotta JC, Rauschning W, Bentson JR, Lufkin RB, Hieshima GB (1985) Magnetic resonance imaging of the brainstem: Normal structure and basic functional anatomy. Radiology 154:375-383 Fontes V (1944) Morfologia do Cortex Cerebral #2. Boletim do Instituto de Antonio da Costa Terreira. Lisbon Geschwind N, Livitsky W (1968) Human brain: left-right asymmetries in temporal speech regions. Science 161:186-I87 Le May M (1991) Left-right dissymmetry-handedness. Presented at the Categorical Course, Imaging the Developing Brain, sponsored by the American Society of Neuroradiology, Washington DC, June 7 - 8 , 1991 Martin JH (1989) Neuroanatomy, Text and Atlas. Elsevier, New York

Naidich TP, Daniets DL, Pech P, Haughton VM, Williams A, Pojunas K (1986) Anterior commissure: Anatomic-MR correlation and use as a landmark in three orthogonal planes. Radiology 158:421-429 Naidich TP, Valavanis AG, Kubik S (1991) Inferior frontal landmarks for identifying the precentral and postcentral gyri along the low convexity on sagittal MRI. Presented at the 29th Annual Meeting of the American Society of Neuroradiology, June 9-14, 1991, Washington DC Nieuwenhuys R, Voogd J, van Huijzen C (1988) The Human Central Nervous System, a Synopsis and Atlas, 3rd revised edition. Springer-Verlag, Berlin Press GA, Murakami J, Courchese E, Berthoty DP, Grafe M, Wiley CA, Hesselink JR (I989) Cerebellum in sagittal plane-anatomic-MR correlation: 2. The cerebellar hemisphere. AJNR 10:667 Press GA, Murakami J, Courchese E, Grafe M, Wiley CA, Hesselink JR (1990) The cerebellum: 3. Anatomic-MR correlation in the coronal plane. AJNR 11:41-50 Riley HA (t943) An Atlas of the Basal Ganglia, Brain Stem and Spinal Cord Based on Myelin-stained Material.Williams & Wilkins, Baltimore Roberts M, Hanaway J (1971) Atlas of the Human Brain in Section. Lea and Febiger, Philadelphia Rumeau C, Gouaze A, Salamon G, Laffont J, Gelbert F, Eisenseidel H, Jiddane M, Farnarier P, Habib M, Perot S (1988) Identification of cortical sulci and gyri using magnetic resonance imaging: a preliminary study. In: Gouaze A, Salamon G (eds) Brain anatomy and magnetic resonance imaging, pp 11 - 31. Springer-Verlag, Berlin Suzuki M, Takashima T, Kadoya M, Takahashi S, Miyayama S, q~aira S (1985) MR imaging of olfactory bulbs and tracts. AJNR 10:955

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63 MRI AND CT: RELATIVE ACCURACY IN EVALUATION OF SEIZURE DISORDER IN PEDIATRIC AGE GROUP M. A. Mikhael Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois PURPOSE: Relative accuracy of MR and CT in diagnosis of lesions in patients presenting with seizure disorder. METHODS AND MATERIAL: Five hundred and fifty two cases (5-20 yrs) presenting with seizure disorder were studied with (pre- and post-enhanced) CT and MRI scans. RESULTS: CT showed primary brain tumor in 56 cases, ischemic and hemorrhagic infarctions in 82 cases, metastases to the brain in 62 cases, arteriovenous malformations and aneurysms proven by angiogram and/or surgery in 22 cases, old scars from infarctions and/or trauma in 10 cases and was negative in the remaining 320 cases. Non-enhanced MR studies detected all lesions shown on CT. Moreover, MR studies showed infiltrating temporal lobe tumors, proven by surgery to be infiltrating astrocytoma in 6 cases, posttraumatic infiltrating gliosis in 2 cases, hamartoma of the temporal lobe in 2 cases, and temporal lobe sclerosis in 3 cases, out of the 320 cases with negative CT scans. The post-enhanced MR scans detected small metastases (4 cases), capillary angiomas (3 cases), small lesions of primary brain lymphoma (2 cases) which were not seen in CT scans (pre- and postenhanced) nor detected by the non-enhanced MR studies.Thus, CT scan was positive in 232 cases and was negative in 320 cases, missing 22 cases with pathological abnormalities detected only by MR. The nonenhanced MR study missed 9 lesions. Some of these lesions were surgically curable (hamartomas, angiomas and temporal lobe sclerosis) and others were helped by medical treatment. CONCLUSION: We feel that pre- and post- enhanced MR scan is the study of choice for the diagnosis of lesions in cases presenting with Seizures and the diagnostic work-up is not complete without an optimum pre- and postenhanced MR study.

64 M A G N E T I C R E S O N A N C E DIAGNOSIS OF MESIAL T E M P O R A L SCLEROSIS. M.Bracchi, M.Casazza°; R.Spreafico o, M . A . V a g h i * Dept. of Neuroradiology, Universit~ di Torino o Dept. of Neurophysiology, Istituto Neurologico, Milano • Dept. of Neuroradiology, istituto Neurologico, Milano Mesial temporal sclerosis is the most f r e q u e n t cause of temporal lobe epilepsy; there is now the possibility to d e m o n s t r a t e it with Magnetic Resonance. The diagnostic criteria are atrophy of the h i p p o e a m p u s with increased signal in T 2 WI, or defined a s y m m e t r y between the two sides. A m o n g a population of more t h a n 100 patients with temporal lobe epilepsy and negative CT e x a m i n a t i o n we have selected 33 cases with MR findings suggesting mesial temporal sclerosis. 13 were females and 20 were males, aged between 14 and 64 years (mean 36 years); the age of onset ranged between 3 m o n t h s to 49 years, with a m e a n of 14,2 years. Early c h i l d h o o d convulsions were present only in 7 patients, and history of perinatal sufference in 3. The side of possible mesial temporal sclerosis detected by MR was in a g r e e m e n t with the clinical and EEG lateralization in 31 o u t 33 cases. T h e various aspects of the lesions, their locatizations, the association with other cortical lesions and the differential diagnosis are discussed.

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IS GADOLINIUM HELPFUL FOR SCREENING MRI IN PARTIAL COMPLEX EPILEPSY? WP Sanders, G Barkley, EM Spickler, R Si!bergleit Henry Ford Hospital, Detroit, MI, U S A

T E M P O R A L LOBE S U R G E R Y IN PARTIAL EPILEPSY: MRI IN P O S T O P E R A T I V E C O N T R O L B. O s t e r t u n , C. Cedzich*, L. Solymosi, M. Reiser D e p a r t m e n t s of Radlology/Neuroradiology a n d Neurosurgery*, University of Bonn. FRG

We prospectively compared T2 weighted MRI to contrast enhanced T1 weighted MRI for the ability of the sequences to identify lesions in patients with the typical clinical and EEG findings of partial complex epilepsy (PCE). 3 neuroradiologists independently reviewed axial and coronal proton density (PD) and T2 weighted images of patients w i t h PCE scanned at 1.ST. Separate analysis of post gadolinium (0.1mmol/kg) T1 weighted images was performed at a later date, without knowledge of the findings on the T2 weighted studies. In 50 patients, there were 34 normal exams. Of the 16 abnormal cases, only 3 showed abnormal enhancement, and all of these three lesions were readily identified on the T2 and PD weighted images. In contrast, there were 7 cages in which white matter lesions were not visible on the enhanced study. The remainder of abnormalities were morphologic (hydrooephulus, arachnoid cyst), and seen equally well on all sequences. SUMMARY: There were no cases in this series in which gadolinium enhancement appears to aid in lesion detection for patients with PCE. Our initial data suggests that gadolinium is net helpful for routine screening MRI in patients with PCE.

Pro'pose: Clinical r e s u l t s of partial temporal lobe resections in patients with p h a r m a c o r e s i s t a n t epilepsy, especially reduction of seizure frequency, m u s t be correlated with the morphologic extent of resections, which are best visualized by MRI. Aim of this s t u d y w a s to optimize timing a n d strategy of postoperative MRI. M a t e r i a l a n d Method: 35 patients with p h a r m a c o r e s i s t a n t epilepsy h a d MRI pre- a n d postoperatively with intervals of 2-8 weeks. Spin-Echo-lmaglng included s t a n d a r d T2 weighted t r a n s v e r s a l a n d TI weighted s c a n s (5 m m slice thickness) in sagittal, coronal a n d modified t r a n s v e r s a l "temporal" planes. The extent of resection w a s m e a s u r e d in all 3 p l a n e s allowing a volume-estimation. MRI r e s u l t s were c o m p a r e d with surgical reports. R e s u l t s : Early postoperative MRI within 4 weeks after s u r gery often allows n o clear delineation of t h e resection borders d u e to persisting h a e m o r r h a g e . T r a n s v e r s a l s c a n s parallel to t h e OML a s well a s "temporal" s c a n s often m i m i c incomplete resection with p e r s l s t a n c e of h l p p o c a m p u s by p a r t s of t h e frontal lobe dropping Into t h e resection hole. Only coronal a n d sagittal slices adequately d e m o n s t r a t e this finding. C o n c l u s i o n : MRI s h o u l d be performed 6-8 weeks after partial temporal lobe resections a n d m u s t include images In 3 p l a n e s (coronal, saglttal, temporall. The volume of t h e resection hole ls n o reliable p a r a m e t e r d u e to significant d i s p l a c e m e n t of frontal lobe s t r u c t u r e s .

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DIAGNOSIS OF CEREBRAL MALFORMATIONS WITH MRI AND REAL TIME SONOGKAPHY D.Wimberger, G.Zoder, G.Bernert, L.Prayer, E.Schindler and H.Imhof; MR-Institute and Departments of Radiology and Neurology, University of Vienna; Kinderklinik Glanzing der Stadt Wien

MRI OF CAVERNOUS SINUS SUBARACHNOID DIVERTICULL~I G.C. Dooms, P. Mathnrin, G. Corn~lis UCL Saint-Luc

Purpose of the study was to evaluate diagnostic contributions of MRI compared with real t i m e sonography (RTS) findings concerning cerebral malformations in infancy. We examined 42 infants and children, aged from 1 day to 4.5 years, in whom a cerebral malformation had been diagnosed or assumed, based on ~TS findings. MRI was done using a 1.5 or a 0.5 tesla superconducting system with TI- and T2-weighted SE as well as IR sequences. For RTS we used a mechanical sector scanner working at 5 or 7.5 MEz. Time between MRI and RTS ranged from 2 days to 4 years. RTS diagnoses were: Dandy Walker Complex (14), agenesis of corpus'callosum (8), holoprosencephaly (2), septal agenesis (5) , combined malformations (9) , not classifiable (4). In classifiable cases RTS and MRI diagnoses correlated roughly. RTS was limited in cases of large hemorrhage (2) and of a narrow fontanels (2). MRI diagnosis could be established in these cases. Complementary MRI information concerning disturbance of myelination, grey/white matter differentiation and assotiated malformations was obtained in 23 cases, which modified prognosis and/or therapy in 14 infants. Our results suggest that MRI essentially influences further management of about I/3rd of infants and children with cerebral malformations. RTS will remain the primary screening method.

69 CRANIOSYNOSTOSIS E.Donauer (1), C.Faubert (2/3), M.Bernardi (I), D.Neuenfe]dt (l) Departments of Neurosurgery (1), Neurorodiology (2) and Diagnostic Radiology (3), Saarlond-University, Homburg-Saar, FIRG Concerning the pathogenesis of cranlosynostosis, two contrary theories exist: on the one hand the premature closure of the skull sutures cause the deformities of the neuro- and visceracranium with consecutive deformation of the skull-base: on the other hand the deformity of the skull-base is regarded as the primary malformation, which is responsible for the development of a premature fusion of the sutures and other skull anomalies. We have examined 52 children with craniosynostosis before and after operative treatment (clinical and radiological follow up between 2-121 months). The examinations included beside a physical and neurological examination, especially measurements of head circumference and skull index. This permitted a detached judgement about the postoperative skull-dimensions. 800 measurements were statistically evaluated. An operative correction of the suture-anomaly by operative resection of the sutures and by creating artificial sutures in individually fitted surgical technique gave good functional and cosmetic satisfactory results. Our results support the theory that the premature closure of the skull is responsible for craniosynostosis.

A retrospective study was performed to assess the MR appearance of cavernous sinus suharachno[d diverticulum in patients presenting with nerve palsies related to a clinical cavernous sinus syndrome. Four patients (one male and three females)(age range : 24-72 years) were included in the study. MRI findings were correlated with computed tomography and metrizamide CT cisternography findings in all patients. The MR examinations were performed with a super conducting magnet Philips Gyroscan S15 operating at 1.5 Tesla. T| (TR=415 msee and TE=20 msec) and T2 (TR=2100 msec; TE=50 and IO0 msec) weighted images were performed in every patient. T] weighted images were also performed following IV injection of gadolinium-DTPA (0.] millimole per kilo body weight). In all four patients presenting with six cavernous sinus lesions, MRI studies demonstrated enlargement of the cavernous sinus. The lesion within the cavernous sinus appeared multiloculated in one patient; its signal intensity follows that of the CSF in the opto-ehiasmatic cistern on both T] and T2 weighted images. There was no contrast uptake of the tumor after contrast injection. Therefore, differential diagnosis with other more common intracavernous lesions (including meningiomas, neuromas and aneurysm) was very easy to perform4 In conclusion, MRI is an exquisite noninvasive modality for identifying this relatively rare entity affecting the cavernous sinus for performing the differential diagnosis between various pathological process affecting the cavernous sinus.

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Special Focus Session (ESNR)

Special Focus Session: The Role of PET in Neuroradiology Chairman: G. Di Chiro, Bethesda, USA

10.20 am

PET and the Neuroradiologists G. Di Chiro, Bethesda, USA

•0.30 am

The Role of PET in Neuroradiology R. S. J. Frackowiak, London, United Kingdom

11.00 am

PET in the Evaluation of Cerebrovascular Disease D. Brooks, London, United Kingdom

11.30 am

PET in Brain Tumors M.J. Fulham, Bethesda, USA

12.00 am

Neurotransmitter-Receptor Studies with PET J.C. Baron, Caen, France

12.30 pm

Discussion

12.40 p m - 01.40 pm

Lunch

Honorary Lecture (ESNR)

In recognition of his pioneering work in microneurosurgery and his special contributions to the field of neuroradiology, the ESNR established for this year a Honorary Lecture, to be delivered by Professor M.G. Ya~argil. 01.45 pm-02.30 pm

Honorary Lecture: Advances and Limits of Diagnostic and Interventional Neuroradiology - A Neurosurgeon's Perspective M.G. Ya~argil, Zurich, Switzerland Chairmen: T. Greitz, Stockholm, Sweden and T.H. Newton, San Francisco, USA

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PET and the Neuroradiologists G. Di Chiro National Institutes of Health, Bethesda, Maryland, USA Imperceptibly, almost without realizing it, neuroradiologists have been moving toward functional evaluation, as opposed to mere, rigid anatomical recognition. This evolution has accompanied, and in fact has been caused, by the changes in our tools for observation, i.e., the imaging equipment. The image created by the x-ray beam is modulated by few, in fact mostly by one single parameter, the electron densit?: Let us take instead the MR image. This is dependent on a multitude of factors which reflect only in part the morphology of the structure being examined, and more closely are determined by its functional features. To make things more complex, these factors are interconnected, each affecting, in a positive or negative fashion, the impact of the other parameters on the final product, the image. While early in our experience with MRI, we thought that we had to contend only with proton density, relaxation times, and flow, it soon became apparent that we could not disregard chemical shift, magnetic susceptibility, phase and diffusion. With time the MR image appears richer and richer in information, much of it of a functional nature, quite apart from the exquisite display of anatomical detail. Then there is PET. This technique, from its inception, was touted as the bearer of the age of "functional imaging". And indeed, the PET image carries with it some morphological content but, more importantly, a close relationship with functions such as flow, metabolism, or neuroreceptor activity. In fact, PET pictorial representation of the various CNS structures contains, as an inherent component, a rapport of proportionality between "strength" of the registered signal and function. It is in PET imaging that the form-function alliance appears more evident. Examples of this correlation in PET abound. For instance, in our laboratory we have: 1) Shown that the cerebral metabolic rate per unit volume is inversely proportional to brain size, confirming the intuitive notion that brain work, unlike muscle work, is independent of organ size; 2) Established a positive correlation between grade of malignancy of a brain tumor and its degree of glucose utilization; 3) Demonstrated the phenomena of deafferentation (including crossed cerebellar

diaschisis) and deefferentation in cases of brain tumors; 4) shown different metabolic behavior of the cerebellar cortex vs. the deep cerebellar nuclei; 5) Described the imaging equivalents of the tumor-related hemianopsias; 6) Established criteria for the recognition of radiation necrosis; 7) Illustrated modifications of cerebral function by a number of drugs, including barbiturates and apparently (studies underway) steroids; 8) Elucidated some pathophysiological aspects of the movement disorders; 9) Correlated degree of metabolism with concentration of some metabolites by associating PET and Magnetic Resonance Spectroscopy; 10) Introduced (apparently with success: studies underway) a ligand for the ubiquitous and critically important NMDA receptors. The acceptance of PET by the neuroradiologists however, has been noticeable only in one respect, i.e. its absence. When at neuroradiological meetings I start talking about PET, the hails are empty. This disinterest by the neuroradiologists is the result of a multitude of factors, among which the clubbish and occasionally arrogant attitude of the original "PET community" (which included very few neuroradiologists). The lack of adequate neuroradiological representation in the PET domain is unfortunate because PET offers specific and unique advantages for the study of certain neurological diseases, particularly the epilepsies, brain tumors, and the dementias. The future possibilities of PET are without boundaries, especially in the areas of movement and neuropsychiatric disorders, as well as in certain aspects of the cerebrovascular diseases. What is needed in the PET coterie is new blood, and this can only be transfused by" a large group, such as that represented by clinical experts, as the neuroradiologists certainly are. The protagonists in PET development have to realize that elitism inescapably leads to a sterile environment where the initiated speak to and reach only the initiated. On the other hand, the clinically inclined specialist (read neuroradiologist) should not be frightened off by some aspects of PET methodology that may appear abstruse. Positron emission tomography is utter simplicity compared to the complexities of the nuclear magnetic resonance experiment.

The Role of PET in Neuroradiology R. S.J. Frackowiak MRC Cyclotron Unit, Hammersmith Hospital, London, UK Positron emission tomography is a technique that uses tomographic principles of image reconstruction with tracers carrying positron emitting isotopes to provide quantitative maps of the distributions of biologically interesting molecules in the brain. The technique has extremely high sensitivity and is truly quantitative as a direct result of the physical properties of positron emission. This has led to the development of numerous techniques for the measurement of various biological variables such as cerebral blood flow, energy metabolism, pH, blood brain barrier leakage, protein metabolism etc.

The application of PET to the neurosciences has followed 2 main areas. The first involves the investigation of the function of the brain by the mapping of changes in cerebral blood flow brought about by specific tasks or manipulations. This usually involves the use of oxygen-15 labelled water as a flow tracer. Techniques have become much more sophisticated in recent years with the improvement in sensitivity and resolution of modern cameras. These techniques have been of particular value in the investigation of the functional mapping of the human cortex and have greatest promise in the fields of

S 104 behaviouraI neurology and neuropsychiatry. The second area involves the use of tracers of neurotransmitter specific binding sites, for example the vesicular storage of dopamine, the D 2 receptors, monoamine oxidase B etc. These tracers have been of considerable use in the differential diagnosis of degenerative disorders of the brain and in particular of the movement disorders. The use of static imaging of cerebral energy metabolism has become clinically useful in a number of areas and in particular in the differential diagnosis of the dementias, the localisation of the focus of epileptic activity in temporal lobe epileptics being

prepared for surgical therapy, and in the differential diagnosis of recurrent cerebral tumor from radiation necrosis. The use of tracers in the preclinical detection of the disease has become a reality with the detection of carriers of the Huntington gene and more recent suggestions that Parkinson's disease and Alzheimer's disease may be preceded clinically by changes in the pattern of resting cerebral metabolism. The lecture will focus particularly in the first of these areas and examples will be given from investigations of normal physiology and physiology disturbed by disease.

PET in the Evaluation of Cerebrovascular Disease D.J. Brooks MRC Cyclotron Unit, Hammersmith Hospital, London, UK In normal subjects regional cerebral oxygen metabolism (rCMRO2) and blood flow (rCBF) are closely coupled, grey and white matter both extracting 40% of the available arterial oxygen supply. If a fall in cerebral perfusion pressure leads to ischaemia, the reduction in blood flow is compensated by a rise in arterial oxygen extraction towards 100% in order to maintain levels of oxygen metabolism. A failure to improve perfusion pressure may result in infarction, cerebral oxygen extraction and metabolism failing to low levels. With recanalisation the blood flow of the infarcted area frequently rises to inappropriately high levels, the so-called state of luxury perfusion. Using inhaia15 t5 tion of 02 and C 02 to measure rOER, rCMRO2, and rCBF, PET can detect areas of viable ischaemic tissue and distinguish them from infarcted tissue. In this way the use of revascularisation techniques to reverse acute Strokes in evolution can be rationaiised. If infarction has already occurred, and luxury perfusion is established, the use of haemodilution, vasodilators, or surgical methods to further increase cerebral blood flow is inappropriate. Not only are cerebral blood flow and metabolism coupled in normal brain, but cerebral blood volume (rCBV) is also coupled to blood flow, the rCBF: rCBV ratio being 10 min -1 for both grey and white matter. If carotid arteries become critically stenosed, a reactive vasodilatation of the distal circulation o c -

curs which results in a fail in vascular resistance and an increase in rCBV to maintain blood flow. A fall of the rCBF: rCBV ratio to 6 min-1 results in maximum vasodilatation is present. At this stage any further fall in cerebral perfusion pressure leads to a fall in blood flow, and a compensatory rise in oxygen extraction. By measuring rCBV with 11CO or C150 inhalation, PET can assess the vasodilatation secondary to extracranial artery stenosis, and so rationalise the use of carotid angioplasty or endarterectomy on haemodynamic grounds. Lacunar infarcts may result in extensive functional disconnection (diaschisis) and this makes PET a more sensitive tool than CT or MRI for detecting stroke. The final clinical outcome of patients who have ha~l a cortical infarct has been shown to correlate inversely with both the extent of functional disruption and the level of metabolism in the affected area. PET can also reveal the adaptive mechanisms the brain uses to effect a functional recovery from stroke, detecting abnormal activation of the ipsilateral sensorimotor cortex and contralateral cerebellar hemisphere when hemiparetic patients use their affected limbs. Finally PET can be used to study the action of cerebral vasodilators, such as calcium antagonists, or protective agents, such as glutamate receptor blockers, on cerebral metabolism and haemodynamics. In this way the efficacy of therapeutic agents in stroke can be directly monitored.

PET in Brain Tumors M.J. Fulham National Institutes of Health, Bethesda, Maryland, USA PET has provided insights into many aspects of brain tumor biology, from glucose and oxygen metabolism to blood flow, pH, status of the blood-brain barrier, amino acid uptake and pharmacokinetics of delivery of chemotherapeutic agents. The evaluation of glucose metabolism in brain tumors with PET and [18F] Fluoro-2-deoxyglucose (FDG) [Di Chiro et al., Neurol 32, 1321 (1982)] is based on the 2-deoxyglucose autoradiographic model developed by Sokoloff [Sokoloff et al., J

Neurochem 28, 897 (1977)]. The method has been used extensively in the diagnosis and management of patients with brain tumors. On the basis of glucose utilization rate (GUR), PETF D G is able to distinguish high-grade malignant tumors from slower-growing, low-grade tumors. In addition, after therapy has been instituted, PET-FDG can differentiate necrosis due to treatment (radiotherapy or chemotherapy) from recurrent tumor.

S 105 This work has been extended by the comparison of PETFDG with Proton Magnetic Resonance Spectroscopy (MRS) [Alger et al., Radiology 177, 633 (1990)]. Currently, clinical Proton MRS (1.5 Tesla) allows the determination of cholinecontaining compounds, creatine, N-acetyl-aspartate (NAA) and lactate. A trend has been observed where tumors with higher GURs display an increased turnover of lactate, consistent with the hypothesis [Warburg, Science t23, 309 (1956)] that malignant tumors shift their energy metabolism toward increased aerobic glycolysis. Oxygen metabolism has been studied in gliomas [Rhodes et al., Ann Neurol 14, 614 (1983)] and it has been shown that gliomas extract a lower fraction of oxygen than normal brain, which suggests that gliomas are adequately oxygenated. A surprising finding (PET with [11C]dimethyloxazolidinedione) ' was that the pH of brain tumors was more alkaline than normal brain [Rottenberg et al., Ann Neurol 17, 70 (1985)]; this has been confirmed with phosphorous MRS [Radda, Science 233, 640 (1986)]. The assessment of tumoral protein synthesis has been attempted with a number of amino acids. The largest experience has been obtained with [~lC]methionine [Bergstrom et al., J

Comp Assist Tomogr 11,384 (1987)]. This agent appears to be useful in defining the extent of tumors. However, its mechanism of uptake seems to be related mainly to a saturable process (capillary transport) rather than to increased amino-acid requirements for protein synthesis. Other tracers (putrescine, tyrosine, pyruvate) have been proposed and tested, mostly in small series of patients. More recently, attention has focused on imaging peripheral benzodiazepine receptors (PBZ) in gliomas. There is experimental evidence [Pawlikowski et al., Acta Neurol Scand 77, 231 (1988)] that benzodiazepines may regulate glial cell proliferation via the PBZ. The PBZ ligands Ro5-4864 and PK 11195 have been labelled with 11C. However, only [11C]-PK 11195 has been shown to bind to human gliomas [Junck et al., Ann Neurol 26, 752 (t989)], whereas no specific binding to astrocytomas was found with [1tC]Ro5-4864 [BergstrOm et al., Acta Radiol 369, 409 (1986)]. It is not presently known whether [llC]-PK 11195 will be able to distinguish high- from low-grade gliomas. Theoretically interesting is the use of a labelled nucleoside ([11C]_thymidine) to assess cellular proliferative capacity [Conti, J Nucl Med, April, in press (1991)].

Neurotransmitter-Receptor Studies with PET J.C. Baron

INSERM U.320 and CYCERON, Caen, France Changes in the density or affinity of specific receptor/neurotransmission systems in discrete brain regions may be important in the understanding of neurological and mental disorders. Although receptor density can be measured post-mortem, studies performed during life are obviously of much greater clinical and pharmacological relevance. Positron Emission Tomography (PET) allows noninvasive monitoring of the time-course of regional tissue tracer concentration following systemic administration of tracer amounts of a radioligand known to interact selectively with specific binding sites, allowing to probe in vivo the regional distribution and affinity of the latter. Difficulties in this approach are present at several steps: radiochemistry (synthesis at high specific radioactivity), metabolism (leading to recirculating labeled metabo-

lites), pharmacology (affinity, selectivity, brain penetration and non-specific binding of the radioligand), and quantitation of the ligand-receptor interaction (modelling of pharmacokinetics). Despite these problems, it is now possible to obtain quantitative images of density and/or affinity of several important post-synaptic receptors (dopamine D 1 and D 2 receptors; central and peripheral type of benzodiazepine binding sites; serotonin 5HTa, ~t opiate, and muscarinic receptors), as well as investigate the presynaptic dopamine reuptake sites and the activity of key enzymes of the catecholamine system. In addition to the investigation of neurological and mental diseases, this approach is being increasingly used during drug therapy to measure directly in brain tissue the occupancy of a given receptor or enzyme.

S 106

Scientific Sessions

Concurrent Scientific Session: White Matter and Metabolic Diseases Moderators: J. Ruscalleda, Barcelona, Spain and J. Valk, Amsterdam, Netherlands 02.35 p m - 04.05 pm

Scientific Papers 7 0 - 8 0

04.05 p m - 04.30 pm

Coffee Break

02.35 pm-04.05 pm Scientific Papers 70-80 070

Localized proton spectroscopy of acute and chronic lesions in patients with multiple sclerosis W. Grodd, T. N~tgele, D. Petersen, A. Melms, q2tbingen, Germany

071

076 Brain changes in neuronal ceroid lipofuscinoses (NCL) R. Raininko, T. Autti, P. Santavuori, Helsinki, Finland 077

Unusual MR imaging pattern of cerebral demyelination simulating intracranial neoplasm

M. Gallucci, E Cardona, M. Arachi, A. Bozzao, A. Splendiani, A. Cifani, O. Migliori, B. Orlandi, UAquila/Rome, Italy

N. Bontozoglou, E.D. Gotsis, L. Stylopoulos, S. Doris, Z. Kapsalakis, Athens, Greece 078 072 MRI in Parkinson's disease D. Ott, S. Schneider, E. Feifel, C. Lacking, Tt~bingen/ Freiburg, Germany 073 Usefulness of MRI for evaluating the eye-movement disorders

J. Braun, H. Mandel, Haifa, Israel 075 Wernicke encephalopathy: Evaluation with MR K.H. Chang, H. K. Yoon, K. Lee, M. H. Hart, M.C. Hart, Seoul, Korea

Post-shunting callosai injuries M. Braun, S. Bracard, R. Anxionnat, J.-L. Barat, Ch. Moret, B. Blanchet, J. Roland, J.C. Marchal, L. Picard, Nancy, France

079 Hyperintensity in the globus pallidus on T 1-weighted and IR sequences on advanced liver disease. Follow-up after liver transplantation

A. Tokumaru, T. O'uchi, Y. Kuru, T. Eguchi, H. Maki, T. Kameda, Chiba, Japan 074 The glutaric acidurias: Neuroradiologic features

Pelizaeus-Merzbacher disease: A clinico-radiological follow-up study

J.M. Mercader, J. Peri, X. Perich, A. Pujol, E Graus, A. Rimola, J. Rodes, Barcelona, Spain 080

Grey-white matter ratio in normals and in children with psychomental retardation E Ebner, G. Hipfl, G. Ranner, E Quehenberger, M. Millner, Graz, Austria

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LOCALIZED PROTON SPECrROSCOPY OF ACUTE AND C H R O N I C LESIONS IN PATIENTS W I T H M U L T I P L E S C L E R O S I S W. Grodd1, T. Nfigelc1, D. Petersen1, A. Melms2 *Department of Neuroradiologyand 2Neurology, University uf Tiibingen

Unusual MR Imaging Pattern of Cerebral Demyelination Simulating Intracranial Neoplasm N B o n t o z o g l o u , ED G o t s i s , L S t y l o p o u l o s , S Doris, Z K a p s a l a k i s Institute ENCEPHALOS, Halandri, Athens, Greece

Purpose: The diagnostic potential of volume selective proton magnetic resonance spectroscopy (MRS) was evaluated in vivo in patients with acute, subacute a n d chronic lesions of multiple sclerosis. Patients and Methods: 18 patients (11 female, 7 male between 12 a n d 48 years of age) with white matter lesions in different states of evolution were examined by proton spectroscopy in conjunction with magnetic resonance imaging of the brain on a whole body imager at 1.5 T. Volume selection was achieved with a spin echo technique with voxel of 23-33 cm ~ size. Two spectra with 256 acquisitions, a T R of 1.5 s and a TE of 135 and 270 ms were acquired to ensure the identification of lactate. Results: In respect to normal spectra with prominent peaks of N-acetyl-aspartate (NAA), creatine/phospho-creatine and choline a decrease of N A A a n d a n increase of choline was found in acute lesions indicating axonal d a m a g e and destruction of myelin. Additional signals f r o m lactate were detectable in the acute and subacute plaques due to surrounding e d e m a and anaerobic glycolysis. In chronic lesion the changes of N A A and Ch w e r e partly reversible and lactate disappeared. Conclusion:

PURPOSE: Atypical, misleading patterns of cerebral demyelination are not uncommon. Demyelination can appear on MR images as single lesion simulating aggressive brain tumor. T h e p u r p o s e of this s t u d y is to f i n d distinctive MR features. METHODS AND MATERIALS: We present four cases of pathologically proven demyelination appearing on M R s t u d i e s as b r a i n tumors. Spin-echo TIW a n d T 2 W i m a g e s w e r e o b t a i n e d on a 1.5 T e s l a magnet. Pathologic diagnosis was from surgical biopsy. R E S U L T S : A l l l e s i o n s h a d i n c r e a s e d T1 a n d T2 r e l a x a t i o n times. T h r e e of the l e s i o n s were located at the cerebral hemispheres, affecting gray and white matter and one lesion was affecting mainly the splenium of the c o r p u s c a l l o s u m . L e s i o n s i z e v a r i e d f r o m 3 to 6 cm. Perifocal white matter edema was demonstrated indicating malignant neoplasms, s u c h as a s t r o c y t o m a s . Although in all c a s e s there was mass effect this was minimal considering the size of the a b n o r m a l i t i e s . CONCLUSION: Although large space occupying pathologic processes with surrounding white matter edema are typical features of intracranial neoplasms, the a b s e n c e of s e v e r e mass effect, especially in y o u n g adults, m a y suggest demyelination as a diagnostic alternative.

T h e results demonstrate that proton MRS can differentiate between acute, subacute a n d chronic plaques on the base of spectral changes, reflecting different metabolic and inflammatory states of the disease.

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MRI IN PARKINSON DISEASE O Ott*(**), S Schneider***, E Feifel** and C L~cking*** * Dpt of Neuroradiology, T~bingen, ** Dpt. of Radiology, Freiburg, ***Dpt. of Neurology, Freiburg

USEFULLNESS OF MRI FOR EVALUATING THE EYE-MOVEMENT DISORDERS A.Tnkumaru I , T . O ' u c h i l , Y.Kuru 2 , T.Eguchi3 , H.Maki 4 , T.Kameda 3 Dept of Diagnostic Radiology~ , Neurosurgery3 and Neurology 4 , Kameda General H o s p i t a l Dept. of D i a g n o s t i c R a d i o l o g y , J u n t e n d n U n i v e r s i t y 2

There are various papers on "Ironimaging" with MRI describing the detection of pathological iron concentrations on the basis of increased signal loss in the basel ganglia. This study including 30 pts with parkinson disease and 3 with neuroleptic-induced parkinsonism and 26 normal volunteers aimed to correlate the subjective impression of signal reduction to a quantitative signal intensity index (SII) and a calculated T2 value and to establish normal and abnormal ranges for individual nuclei. The examinations were performed at a 2T whole-body system using a multiecho CPMG sequence ( TR = 3170ms, TE = 32 - 256ms, 18 min. scan time). SII was defined as ratio between absolute intensity values of the third echo image of interesting regions (dentate and ruber nuclei, thalamus, putamen, pallidum and caudatum) and normal white matter in the same slice. T2 values were calculated from the intensity decay from 2nd to 8th echo. In the reference group (16 - 78 yrs) T2 values didnot correlate significantly to SII nor age. A highly significant correlation exists between SII in the putamen and age. The Parkinson ( 19 -84 yrs) group didnot show important differences in the T2 or intensity values for individual nuclei. The pars compacta of the substantia nigra tended to be brighter. The darkest nuclei occurred in agerelated parkinsonism in whom other ischemic lesions helped to establish the symptomatic origin. From the extensive measurements and optic analysis in our patient group we coyld not esT~blish a valid index nor T2 value allowing the dignosis of increased iron deposition in Parkinson disease.

Purpose: The p u r p o s e o f t h i s s t u d y i s to e v a l u a t e t h e r e s p o n s i b l e l e s i o n s of eye-movement d i s o r d e r s by MRI. M a t e r i a l s and Methuds: Twenty t h r e e p a t i e n t s w i t h e y e movement d i s o r d e r s due t o b r a i n s t e m i n f a r c t i o n s , 13 males and I0 f e m a l e s , r a n g i n g from 42 t o 84 y e a r s o f a g e , were s t u d i e d by MRI. All examinations were performed on a 1.5T s u p e r c o n d u c t i n g magnet. Images were a c q u i r e d i n t h i n s l i c e transverse, c o r o n a l and s a g l t t a l orientation which was parallel or v e r t i c a l to the long a x i s of b r a l n s t e m (basiparallel cut) in order to get more precise i n f o r m a t i o n about t h e c l i n f c o t o p o g r a p h i c c o r r e l a t i o n s in p a t i e n t s w i t h eye-movement d i s o r d e r . R e s u l t s : B r a i n s t e m l e s i o n s were d e m o n s t r a t e d on MRI w i t h beslparallel cut in t h e d o r s a l and medial s i d e of brainstem where most important structures of the o c u l o m o t o r system e x i s t e d . MRI also showed pseudohypertrophy of inferior olivery nucleus in association with lesions of the central t e g m e n t a l t r a c t Or d e n t a t e n u c l e u s in 10 o f 23 p a t i e n t s as enlargement of the ventral side of the medulla oblongata w i t h T2 elongation. Conclusion: Thin slice MRI with basiparallel cut could provide insights in clinicotopographlc correlations in pathients w i t h eye-movement disorder. ~ I also could detect the transsynaptic degeneration, for example, pseudohypertrophy of inferior olivery nucleus.

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THE GLUTARIC ACIDURIAS: NEURORADIOLOGICFEATURES J. Braun and H. Mandel Departments of Diagnostic Radiology and Pediatrics, RambamMedical Center, Haifa, Israel

WERNICKE ENCEPHALOPATHY : EVALUATION WITH MR KH Chang, KK Yoon, K Lee, HH Han. MC Han Department of Radiology, Seoul National University College of Medicine, Seoul, Korea

The Glutaric Acidurias comprise two d i s t i n c t and unrelated e n t i t i e s : I) Glutaric Aciduria type I (GA-I) which is a disorder of lysine and tryptophan F,~etabolism due to deficiency of glutaryl-CoA-dehydrogenase; and 2) Glutaric Aciduria type II or multiple acyl-CoA dehydrogenation deficiency which is due to deficiency of ETF or ETF-QO from the mitochondrial respiratory chain. Five children were evaluated: 2 with GA-I and 3 siblings with GA-II. Diagnosis was established in a l l cases by Gas Chromatography-Mass Spectrometry (GC-MS) of organic acids in urine and by measurement of enzyme a c t i v i t y in cultured skin fibroblasts. The c l i n i c a l picture was variable and nonspecific: hypotomia, dystonic movements, hemiparesis, hypoglycemia, acidosis and hepatomegaly. Brain CT in GA-I patients showed marked atrophy of temporal lobes with "bat wings" d i l a t a t i o n of the Sylvian fissures and insular cisterns, and hypodensity of the lenticular nuclei. In GA-II patients %here was diffuse cerebral atrophy in a l l cases as well as punctate hypodensities of l e n t i c u l a r nuclei and white matter hypodensity of cerebellum in one. Recognition of radielogic manifestations of inherited metabolic defects can direct the c l i n i c i a n to this p o s s i b i l i t y , in obscure cases, and narrow down the spectrum of d i f f e r e n t i a l diagnosis to specific metabolic entities.

Eight patients with clinical diagnosis of Wernicke encephalopathy were examined by magnetic resonsnace (MR) imaging

to evaluate the capability of detecting characteristic lesions of this disease. MR images were obtained on either a 2.0T (6 cases) or a 0.ST scanner (2 cases) using spin-echo pulse sequences. In 2 cases, more than one follow-up MR studies were performed. Five patients (four chronic alcoholics and one with hyperemesls gravldarum) showed both mamillary body atrophy and patchy lesions around third ventricle, medial dorsal aspect of bilateral thalami, rectum of midhrain and periaqueducta] gray matter. Two other patients (hyperemesis gravidarum and chronic alcoholism each) showed only atrophic mamillary body. The last patient with severe vomiting after gastrojejunostomy showed only the diencephaic/mesencephaliclesions. Follow-up MR one-and 5 weeks after thiamine treatment showed decrease of previous diencephalic/mesencephalic lesions but no change of mamillary bodies. Atrophy of mamillary bodies was appreciated best on Tl-weighted s a g i t t a l images, while dlencephalic /mesencephalic lesions were best seen on proton-density-and T2-weighted images as high signal i n t e n s i t i e s . In conclusion, MR is very useful in demonstrating c h a r a c t e r i s t i c lesions of Wernicke encephalopathy and in e v a I u a t i n g the e f f e c t i v e n e s s of treatment on follow-up study.

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BRAIN CHANGES IN NEURONAL CEEOID LIPOFUSCINOSES (NCL) R. Raininko, T. Autti and P. Santavuori Departments of Diagnostic Radiology and Child Neurology, University of Nelsinki, Finland

PELIZAEUS-MERZBACHER DISEASE: A CLINICOR A D I O L O G I C A L F O L L O W - U P STUDY. M.Gallucci, F.Cardona*, M.Arachi*, A.Bozzao, A.Splendiani, A.Cifani, O.Mig!iori, B.Orlandi Dept. o f R a d i o l o g y , U n i v e r s i t y of L ' A q u i l a * Dept. of Child Neurology, University "La S a p i e n z a " , Rome, I t a l y

We describe findings on brain MRI of patients with three types of NCL: infantile (INCL), variant late infantile (LINCL, Jansky-Bielschowsky disease, JBD) and juvenile (JNCL, Spielmeyer-SjSgren's disease). We examined 32 patients: 8 had INCL (aged 1-6 years), 4 had variant JBD (6-11 y), and 20 had JNCL (6-25 y). 36 healthy volunteers or patients without a disease affecting the brain were used as controls (age range 1-30 years). MR examinations were performed at 1.0 T. Axial slices with a sequence SE 2500/22-90 and sagittal Tl-weighted images were obtained in all cases. On T2-weighted images, intensities were measured in several regions and intensity ratios between certain structures were calculated. Results:- INCL: Generalized brain atrophy was found even in the youngest child. Progression of the atrophy was rapid. Corpus eallosum was very thin and especially white matter was severely reduced. %~hite matter was hyperintense and the thalami showed a severe intensity loss. Basal ganglia also appeared hypointense. - Variant JBD: Brain atrophy was found in all patients. Hyperintense rims were seen in the white matter around the bodies and atria of the lateral ventricles. Thalami and/or putamina were hypointense. - JNCL: Atrophic changes were found in patients over ii years of age. The corpus callosum was thinner than in the controls (p<0.O01). Intensity difference between the frontal cortex and peripheral white matter was lower and between periventricular and peripheral white matter higher than in the controls (p<0.01). Signal intensity of the thalami was decreased in 7/9 patients over 15 years of age and even in some younger patients. Decreased signal intensities were also found in some basal ganglia. Conclusion: MRI is valuable in the differential diagnosis of suspected INCL and JBD, but also in the investigation of pathogenesis of NCL disorders.

P M D is a rare CNS degenerative disease d i f f u s e l y a f f e c t i n g the white matter in c h i l d r e n . S i n c e the c l a s s i f i c a t i o n p r o p o s e d b y N o r m a n in 1961, a t l e a s t t h r e e d i f f e r e n t t y p e s of p a t h o l o g y are considered in the same c l i n i c a l h e a d i n g of PMD: the c l a s s i c a l form, the connatal one and the a d u l t type. Five subjects affected by the disease (three c l a s s i c a l type, o n e c o n n a t a l and o n e female) were enrolled in a clinical-imaging trial. C l i n i c a l and M R follow-up evaluation were p e r f o r m e d in a p e r i o d ranging from 2 to 5 years. T h e r e l a t i v e s of all the patients affected by classical PMD also underwent MR examination. The MR appearance was in all subjects quite typical, and neither clinical nor imaging difference between the typical Xlinked and non X-linked forms was found. A c l o s e c o r r e l a t i o n b e t w e e n t h e age of c l i n i c a l o n s e t a n d the p a t h o l o g i c a l compromission was o b s e r v e d and n o f u r t h e r progression was found in follow-up studies. T h i s is in a c c o r d a n c e w i t h the p a t h o g e n e t i c h y p o t h e s i s of a p r i m a r y failure in myelin formation. F i n a l l y , e v e n if we found aspecific alterations in o n e of the carriers, our experience suggests that they are f a r f r o m being able to lead to a p r e v e n t i o n of t h e p a t h o l o g y .

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POST-SHUNTING CALLOSAL INJURIES. M. Braun*, S. Bracard*, R . A n x i o n n a t * , J-L Barat**, Ch Moret*, B. Blanchet*, J. Roland*, J. C. Marchal**, L. Picard*. N e u r o r a d i o l o g i c a l (*) (Pr.Picard) & n e u r o surgical(**) d e p a r t m e n t s (Pr.Hepuer) N A N C Y - F R A N C E

HYPERINTENSITY IN THE GLOBUS PALLIDUS ON TI-WEIGHTED AND IR SEQUENCES ONADVANCED LIVER DISEASE. FOLLOW-UP AFTER LIVER TRANSPLANTATION.

We reviewed 1 2 0 p a t i e n t s s h u n t e d for o b s t r u c t i v e h y d r o c e p h a l u s c a u s e d b y t u m o r s , c o n g e n i t a l or p o s t haemorrhagic obstacles. 30 % were shunted via the frontal horn, 70 % via the atrium of the lateral ventricule. Patients were followed by MR Tlweighted sagittal views and axial T2 weighted sequences. Two types of callosal injuries can be described : acute l e s i o n s a r e r a r e (9 %) a n d w e r e f o u n d o n M.R. c o n t r o l s between the 3rd and 15th day after shunting. These lesions consist in a transient callosal edema. Chronic damages are divided into three types : segmental a t r o p h y o c c u r s i n 8 0 % of f r o n t a l s h u n t s a n d o n l y i n 15% v e n t r i c u l e a t r i u m s h u n t s . C a U o s a l " g l l o s l s " a p p e a r s after multiple ventricular punctions (shunting r e v i s i o n s ) , a s a p e r m a n e n t d a m a g e i n v o l v i n g t h e full t h i c k n e s s of t h e c o r p u s c a l l o s u m ( h i g h s i g n a l o n T 2 weighted sequences and low signal on Tlweighted sequences). Callosal cavities occur after numerous transcallosal perforations. They appear as cysts located within the corpus callosum and with a CSF-like content. I n c o n c l u s i o n , a c u t e l e s i o n s (callosal e d e m a ) a r e r a r e , Chronic ones are m o r e f r e q u e n t a n d l i k e l y d u e to multiple transeallosal perforations that lead to segmental atrophy, callosal "gliosis" and cavities. F r o n t a l s h u n t i n g a p p e a r s to b e m o r e a g r e s s i v e t h a n t h e p o s t e r i o r r o u t e . All p a t i e n t s r e m a i n e d s y m p t o m s free.

J.M. Mereader, J.Peri, X. Perich, A. Pu3ol, F. Graus, A. Rimola** and J. Rodes** Departments of Radiology, *Neurology and **Hepatology. Hospital Clznle i Provincial. Universidad de Barcelona. Centro Radiologico Computarizado. Barcelona. Spain MR images of the head were obtained in a prospective series of 45 patients with no-Wilsonian advanced liver disease. ~ e studies were evaluated with IR (1200/30/600) and SE (600/2? and 2000/30.90) techniques at 0.5T (gyrex V Elscint). On TI weighted and IR sequences, 33 of the 45 patients (73%) had a symmetric high-intenslty signal mainly in the globus pallidus. The presence of postural tremor was statistically associated with the MRI lesion. No correlation was observed with type of duration of liver disease, number of episodes of hepatic encephalopathy or routine laboratory analysis. At the present time, ii patients with this lesion in the globus pallidus have undergone a liver transplantation. The MRI scan done 4 to 6 months after transplantation demonstrated a great decrease of the high-intenslty signal in 7 patients and a complete disappearance of the lesion in the other 4 patients. The hlperintensity mainly in the globus pallidus in our patients may be due to the presence of substances with paramagnetic properties or other materials. Our observation that the abnormality decreases after liver transplm~tationsegge~s that this possible accumulation of paramagnetic substance is associated with reversible deposit that disappears once the liver function returns to normal.

80 GREY-WHITE MATTER RATIO IN NORMALS AND IN CHILDREN WITH PSYCHOMENTAL RETARDATION F. Ebncr, G. Hipfl, G. Ranner, F. Quebenberger, M. Millner Karl-Franzens-University Graz, Medical School

Purpose: To establish mean values in normal individuals (age 2-14 yrs) and to assess objectively the ratio between grey and white matter for a better definition of cortical and medullary atrophy. M e t h o d s : A series of 200 children (age 2-14 yrs) were prospectively evaluated for various focal neurologic deficits or to rule out malignancy. Mean age was 8,4 yrs. A second series of 33 children with mental retardation were examined. MR imaging was performed on a 1.5 Tesla superconductive magnet. T2-weighted spin-echo-pulse sequences were obtained. In level of the anterior horns (frontal lobes), posterior horns (occipital lobes) and at the roof of the lateral ventricles (parietal lobes) planimetric measurements were done in order to quantitatively assess morphometric data of cortical area, medullary area and ventricular area. Various statistical methods were applied to calculate mean values, standard deviations, correlation coeefficients and regressions analyses. Results: 1. Scatter plot matrix showed in 6•33 children with retardation increased ventricular volume (18,2 %). 2. Greywhite matter ratio was increased compared to normals in 12/33 patients (36,4 %). The results were statistically significant. Clinical correlation revealed asphyxia syndrome (n=7), delayed myelination (n=5), dysmyelinating diseases (n=4), unknown etiology (n=14). Conclusion: Diminished cerebral white matter is a frequent finding in children with psychomental retardation and can either be due to primary maldevelopment or secondary injuries•

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CAMPRO SCIENTIFIC

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Concurrent Scientific Session: Neurovaseular Imaging Techniques Moderators: H. Hacker, Frankfurt, Germany and G. Salamon, Marseille, France 02.35 p m - 0 4 . 0 5 pm

Scientific Papers 81 - 89

04.05 p m - 04.30 pm

Coffee Break

02.35 pm-04.05 pm Scientific Papers 81-89 081

Development of a ceiling suspended neuroangiographic system for interventional angiography

085

M. Takahashi, H. Bussaka, Y. Yamashita, Y. Korogi, T. Oguni, Y. Sakamoto, M. Harada, Kumamoto, Japan 082

Rotational digital stereoangiography - A new system for 3-D display

Magnetic Resonance Angiography of arteriovenous malformations in the brain: Comparison with MRI and DSA L. Stylopoulus, E.D. Gotsis, N. Bontozoglou, E. Kapsalaki, Z. Kapsalakis, Athens, Greece

086

Color Doppler in carotid occlusion and near occlusion D.H. Lee, A.J. Fox, London, Canada

S.G. Kominami, T. Kumazaki, H. Tajima, T. Oya, K. Gemma, S. Nakazawa, Tokyo, Japan 087

Neck vessels: Comparative imaging

083 MR-Angiograp~" and transcranial-Doppler sonography in cerebrovascular disease

G. Pellicano, S. Colagrande, A. Bartolozzi, A. Tonarelli, M. Angeli, Florence, Italy

F. Angeleri, L. Chiaramioni, N. Foschi, M. Maricotti, A.M. Mauro, E Minciotti, L. Provinciali, U. Salvolini, Ancona, Italy

088 Fluiddynamic investigations of vascular wall protrusions

084

MR phase contrast angiography in the study of brain vessels diseases E Di Salle, S. Cirillo, L. Simonetti, G. Sirabella, S. Tecame, R. Elefante, E Smaltino, Naples, Italy

E. Volle, A. Ruprecht, R. Kraft, J. Eck, E Ginter, G. Lein, R. Gustorf-Aeckerle, Stuttgart, Germany 089

MRI in brain death D.H. Lee, A.J. Fox, London, Canada

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DEVELOPMENT OF A CELLtNG SUSPENDED NEUROANGIOGRAPHiC SYSTEM FOR INTERVENTIONAL ANGIOGRAPHY Takahashi M, Bussaka H, Yamashita Y, Korogi Y, Oguni T, Sakamoto Y, Harada M Dept. of Radiology, Kumamoto University School of Medicine

ROTATIONAL DIGITAL STEREOANGIOGRAPHY ---A N E W SYSTEM FOR 3-D DISPLAY S.G.Kominami, T.Kumazaki, H.Tajima, T.Oya, K.Gemma, S.Nakazawa Department of Neurosurgery and Department of Radiology, Nippon Medical School, Tokyo

A new neuroangiographic unit was developed with a ceiling suspended gantry, capable of rotation (110 ° ) and angulation ( - 4 5 ° ) along the body axis. The gantry could also be rotated 225 ° at the ceiling suspension and sidetracked away from the angiographic table in case of emergency. Two sets of a twin focal X-ray tube and a 12 inch image intensifier were mounted on the gantry in the isocentric and cross-firing position. High resolution 1024 x 1024 matrix digital radiography was obtained with a speed of 30 frames/second, while conventional screen film radiography was obtained 4 films per second. Rapid film changers were installed and interchangeable with the image intensifiers. The lateral I.l. and X-ray tube were placed from either side of the patients. There was no angulated position of the lateral imaging system during the angulated anteroposterior or Towne projection. The automatic repositioning of the gantry was possible to the preset position. Stereoscopic, magnifica-tion and stereoscopic magnification radiography was possible in monoplane and biplane. Switching from fluoroscopy to radiography and vice versa was obtained rapidly and easily. Neuroangiographic as well as interventional techniques were performed expediciously with lower complication rates. Wider space was availabe on the floor for anesthesiologists.

We have developed a new digital angiographic system for 3-D display, which consists of a new rotating X-ray apparatus and a digital processor. This system collects 144 projectional images during 180 degrees transverse rotation of the Xray apparatus in 2.2 sec. A real time display of all images is carried out on two CRT's with an angle of 5 different degrees, so that 3-D images can be observed from any angle, following a single injection of contrast medium. We have applied this system to 25 neurosurgical patents. Ten cerebrovascular aneuysms, eleven brain tumors, and 4 other neurosurgical diseases were examined. Conventional angiography was also performed at the same time for comparison. Aneurysmal necks, which were often difficult to be identified with the conventional angiography, were more clearly demonstrated with this new system. In brain tumors, not only the feeding arteries and tumor stain were better identified, but the relationship between the tumor and the major vessels were also clearly observed with this system. The usefulness of this system in neuroradiology is suggested, and will be expected in interventional neuroradiology.

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MR - ANGIOGRAPHY AND TRANSCRANIAL-DOPPLER SONOGRAPHY IN

MR PHASE CONTRAST ANGIOGRAPHY BRAIN VESSELS DISEASES

CEREBROVASCULAR DISEASE.

Angeleri F., Chiaramoni L., Foschi N., Maricotti M., Mauro A.M., Minciotti P., P r o v i n c i a l i L., S a l v o l i n i U. The MR-Angiography (MRA) l e t a bloodless study of the vessels of the cervical and cerebral d i s t r i c t , with the vantage of the tridimensional reconstruction of the examined vessels. The MRA study was performed with Magnetom Siemens 1.0 T u n i t , using sequences GE with 3D acquisition (FISP). P e c u l i a r i t y , advantages and l i m i t s of the TranscranialDoppler (TCD) are already widely common knowledge. 50 patients affected from cerebra] vasculopatic disease were studied by the two methods. Now on the basis of preliminary results, we suppose that: the MRA is more p r e d i c t i v e f o r morphological findings. On the other hand, TCD is more p r e d i c t i v e for functional i nformat ion. We think that: the c o r r e l a t i o n and relationship between the two methods help to improve the diagnostic and prognos t i c evaluation of the patients.

IN T H E

STUDY

OF

F.Di Salle, S.Cirillo, L.Simonetti, G.Sirabella, S.Tecame, R.Elefante, F.Smaltino U n i v e r s i t y of Naples, II Faculty of Medicine Phase contrast MRA, implemented on a 0.5 T imaging system, has been applied to the study of cerebral aneurysms and A%~s. This flow selective imaging tecnique is thought to be more suitable for m e d i u m and low velocity vessels, but suffers from turbulencerelated phase d i s p e r s i o n artifacts and can be impaired by high complex vessel geometry. The authors evaluate MR phase contrast angiography diagnostic efficacy in the study of 31 aneurysms and 6 AVMs by comparison with DSA, and they investigate the influence of scan conditions on image quality. Only very accurate MR examinations can investigate cerebral vessels with sufficient detail, and it is d i f f i c u l t to explore the whole brain vascular system. In our opinion phase contrast M R A at 0.5 T can be utilized in the follow-up of vascular pathologies and can complete a standard MRI procedure but cannot replace DSA in the production of vascular maps and in the accurate definition of the topography and morphologic details of aneurysms and AVMs.

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85 Magnetic

Resonance Angiography of Arteriovenous

M a l f o r m a t i o n s in the Brain: Comparison w i t h MRI and DSA L. Stylopoulos, ED Gotsis, N. Bontozoglou, E. Kapsalaki, and Z. Kapsalakis Institute ENCEPHALOS, Halandri, Athens, Greece Purpose: To evaluate state of the art M a g n e t i c Resonance A n g i o g r a p h y (MRA) techniques in identifying and c h a r a c t e r i z i n g brain AVM~s. Materials and Methods: 35 patients w i t h known or suspected A r M of the brain (from MRI) were exam i n e d w i t h a 1.5 T system. MRI was available in all patients. In 20 patients DSA was also performed. Results: All cases were p r o p e r l y d e t e c t e d and t h r o u g h selective p r e s a t u r a t i o n a good deal of the feeding vessels and venous drainage was correctly identified. The nidus was c l e a r l y shown in m o s t but not all cases. 3 cases w e r e n e g a t i v e on DSA and were i d e n t i f i e d from the original images in MRA. Phase c o n t r a s t sequences were indispensable in separating the subacute thrombus from flow.

COLOR DOPPLER IN CAROTID OCCLUSION AND NEAR OCCLUSION DH Lee, AJ Fox, University Hospital, London, Canada PURPOSE: To investigate the sensitivity and specificity of color Doppler with low flow sensitivity (1 cm/sec) to differentiate internal carotid (ICA) occlusion from near occlusion. MATERIALS & METHODS: 26 patients with ICA occlusion or near occlusion on angio were studied. All had duplex ultrasound and 24/26 had color Doppler using low flow sensitivity I cm/sec). Ultrasound was usually performed before angio. There were 6 patients with angiographic near occlusion, and 20 with angiographie occlusion of the ICA. RESULTS: Four of 6 patients with near occlusion had low flow shown in the ICA, using sagittal and axial imaging. Duplex ultrasound suggested occlusion in all 4. The other two had flow shown on Duplex ultrasound. 18 of 20 Color Doppler examina. tions correctly suggested ICA occlusion. Two showed near occlusion - I performed I month before angio, the other I day prior to angio, which showed tapered occlusion of the distal common carotid artery suggesting interval subintimal hemorrhage. CONCLUSION: Color Doppler is necessary to enable accurate differentiation of near occlusion from occlusion.

Conclusions: C o n s i d e r i n g the high s e n s i t i v i t y of the method, M R A could definitely be used as a technique for AVM's of the brain. Selective presaturation and phase contrast sequences help in c h a r a c t e r i z i n g the lesions. If surgical interv e n t i o n is considered, D S A is r e c o m m e n d e d because of its dynamic nature.

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NECK VESSELS: COMPARATIVE IMAGING

FLUIDDYNAMIC INVESTIGATIONS OF V A S C U L A R WALL PROTRUSIONS

G.Pellicanb,S.Colagrande*,A.Bartolozzi,A.Tonarelli*,M.Angeli Radiology Unit S.M.Annunziata Hospital Florence *Department of Clinical Phisiopathology Radiology Section University of Florence This study deals with actual imaging trends in both occlusive and aneurysmatic neck vessels disease,Morphologycal and hemodynamic correlations are discussed and the role of TC and MRI is particularly stressed. 98 patients,respectively affected by carotid artery (CA) stenosing plaques (90);ICA aneurysms (3);IGV thrombosis (3);ICA dissections (1) and post-surgical CA hematoma (1),were examined with Duplex-Doppler scanning (B-mode and spectral Doppler analysis) and contrast-enhanced CT.In 30 patients,conventional and G.E. MR study of epyaortic vessels was additionally performed. Comparative evaluation of the three Imaging techniques constantly led to the identification of the lesion.It also allowed accurate topographic balance,with regard to both the longitudinal extension of disease and the rate of cross-sectional stenosis.ln most cases,the pathological basis of disease could be non-invasively assessed.CT studies revealed specifically helpful in spatial evaluation of CA disease not properly visualized by B-mode US (hard plaques,cranial bifurcation).Doppler profiles supplied functional evaluation of each lesion by easy identification of hemodinamically significant stenosis,thrombosis and non-critical changes in pulsatile flows patterns. MR presents like a non-invasive,multi-planar,morpho-functional Imaging tecnique.Some information about flow (fast versus slow velocity and/or turbolent flow) can be also obtained in standard images.Nevertheless,small parietal lesions are easily missed or masked by overlapping flow signal artifacts.

E Volle *; A Ruprecht **; R Kraft *; J Eck **; F G i n t e r **; G Lein **; R G u s t o r f - A e c k e r l e *: * Department of Neuroradiology, Katharinenhospital Stuttgart and ** D e p a r t m e n t of H y d r a u l i c Machines, U n i v e r s i t y Stuttgart. The flow pattern in v a r i a b l y shaped v a s c u l a r wall p r o t r u s i o n s and v a s c u l a r branchings are analysed by numerical simulation, assuming a laminar flow of a N e w t o n i a n fluid. In this investigation the "Finite Element Numerical Flow Simulation System" (FENFLOSS) is used, a c o m p u t e r code for the s o l u t i o n of the NavierStokes equations. The basic data and the assumptions for the m a t h e m a t i c a l d e t e r m i n a t i o n of 2-D and 3-D model simulations were a constant flow, the vascular d i a m e t e r of the m a i n arterial intracranial vessels, the v i s c o s i t y of a contrast agent bolus within the b l o o d s t r e a m in the presence of rigid and h y d r a u l i c a l l y smooth walls. C o m p l e x conditions of flow could be r e c o r d e d by colour coding in high spatial r e s o l u t i o n using m a t h e m a t i c a l l y d e t e r m i n e d v e l o c i t y vectors for size and direction. The o b t a i n e d theoretical data are c o m p a r e d with contrast media serial investigations by i.a. DSA (12 images/sec) o b t a i n e d in patients suffering from aneurysms with respect to flow phenomena of the bolus. A full u n d e r s t a n d i n g of flow phenomena forms the basis for the correct i n t e r p r e t a t i o n of the flow sensitive 3-D-Magnetic Resonance A n g i o g r a p h y (3-D-MRA).

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89 M R I IN BRAIN D E A T H DH Lee, AJ Fox, University Hospital, London, Canada

PURPOSE: Image patients who are brain dead. MATERIALS & METHODS: High field MRI with T1, proton density and T2-weighted sequences was performed on 2 patients who were clinically brain dead. RESULTS: Both scans showed the same features: 1. Loss of CSF spaces on the T1 weighted sagittal images 2. "Super normal" brain on proton density and T2 weighted images, due to absent brain, CSF or vascular pulsations 3. Slow flow in the extracranial and intracavernous carotid arteries, with no evidence of signifieant flow voids in distal MCA or ACA branches, and no visible basilar flow 4. Loss of flow void of major cerebral venous sinuses CONCLUSION: MRI offers another imaging modality to complement the clinical diagnosis of brain death.

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m n a m m a t o r y tJlseases

Moderators: G. Scotti, Milan, Italy and S. Cronqvist, Lund, Sweden 04.30 pm - 05.40 pm

Scientific Papers 9 0 - 9 8

05.45 pm - 07.15 pm

General Assembly ESNR

04.30 pm-05.40 pm Scientific Papers 90-98 090 MRI and MRS of herpes simplex meningoencephalitis Ph. Demaerel, G. Wilms, W. Robberecht, K. Johannik, E Van Hecke, C. Faubert, H. Carton, A. L. Baert, Leuven, Belgium and Homburg/Saar, Germany 091

MRI and SPECT in diagnosing and monitoring herpes simplex encephalitis D. Wimberger, M. Schmidbauer, I. Podreka, P. Hitzenberger, L. Prayer, H. Imhof, E. Schindler, Vienna, Austria

092

temporo-mediai hot spot in HM-PAO SPECT" key finding in acute herpes simplex encephalitis "The

H. Henkes, G. Huber, J. Hierholzer, H. J/iger, G. Hamann, U. Piepgras, Homburg/Berlin, Germany 093 Brain changes at various stages of H1V infection R. Raininko, I. Elovaara, A. Virta, L. Valanne, S.-L. Valle, Helsinki, Finland 094 Progressive diffuse leukeneephalopathy (PDL) in AIDS a distinct lesion pattern detectable by CT and MRI H. Henkes, G. Huber, J. Artigas, R. Jochens, W. Sch6rner, U. Piepgras, Homburg/Berlin, Germany

095 CNS-Lymphomas in AIDS patients. Nenromdiology and neuropathology J. Berkefeld, H. Hacker, C. Lang, W. Schlote, Frankfurt, Germany 096

Natural history of cysticercosis on neuroimaging C.S. Zee, S. Destian, J. Ahmadi, H.D. Segall, Los Angeles, USA

097 Giant cerebmAtuberculomas - CT vs MR - analysis of 21 cases A. Kohli, S. 13. Desai, V.C. Shah, O.J. Tavri, P. Rao, Bombay, India 098 An asymptomatic dural fistula, related to an infection by borrelia burgdorferi P.H. Hoogland, M.C. Shoemaker, J.A. VeenendaalHilbers, W.V.M. Perquin, L. Doornbos, The Hague, Netherlands

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MRI AND MRS OF HERPES SIMPLEX MENINGOENCEPHALITIS Ph. Demaerel, G. Wilms, W. Robberecht*, K. Johannik, P. Van Hecke, C. Faubert**, H. Carton*, A.L.Baert Depts. Radiology, and Neurology*, University Hospitals K.U. Leuven, Belgium and Institut ftir Neuroradiologie**, Universit~tskliniken Hombt~g-Saar

MRI AND SPECT IN DIAGNOSING AND MONITORING HERPES SIMPLEX ENCEPHALITIS D.Wimberger, M.Schmidbauer, I.Podreka, P.Hitzenberger, L.Prayer, H.Imhof and E.Schindler; MR-Institute and Departments of Radiology and Neurology, University of 'Vienna

The pro/rose of this study was to analyze the MR findings in Herpes simplex meningoencephalitis (HSME). 11 patients (5 if, 6 Q) with HSME were examined by MRI at 1.5 T. A total of 19 examinations were analyzed. Spin-echo T1 and T2 weighted images were obtained. Gd-DTPA was administrated in 8 patients. Bitemporal high signal areas were seen in 5 patients, while only one temporal lobe was involved in the remaining 6 patients. Gd enhancement was present in 7 patients. Accurate anatomic delineation of the lesions was possible and lesions in the gyms rectus and cinguli could easily be identified. Hemorraghic changes were present in 6 patients and were much better seen on MRI. 1H MRS in one patient showed distinct changes in one lobe and discrete metabolic changes in the contralateral lobe. MRI is clearly superior to CT, as pathological changes may be detected earlier and delineation and extent of lesions is clearer. MRI should become the examination of choice in the diagnosis and followup of HSME, provided that adequate motion control can be achieved. 1H MRS seems promising in evaluating the neuronal loss in HSME.

Purpose of the study was to evaluate MRI and SPECT contributions to diagnosis and monitoring of herpes simplex eDcephalitis (HSE). 10 MRI'i:examinations were peTformed in 7 patients suffering f r o m differer6t stages of the disease; follow-up studies were done in 2Jof them, In 4 cases comparison was made with SPECT (7 studies). For MRI we used a 1.5 tesla superconducting system. TI- and T2-weighted coronal and axial slices were performed, 0.1 mmol Gd-DTPA/kg bodyweight was administered. SPECT was done with a double head rotating scintillation camera in 2x30 6 degree angle steps. The tracer was Tc 99 HMPAO. In MRI the lesions were hypointense on TI- and hyperintense on T2-weighted images; in 3 cases hemorrhage was found. Meningeal contrast enhancement was seen in acute and subacute stages. In early stages, SPECT revealed a high tracer uptake in involved regions which decreased during clinical improvement, whereas MR findings remained unchanged for a longer time. Combination of MRI and SPECT enables early and specific diagnosis of HSE. SPECT reacts more sensitive on therapy related changes than MRI. MRI, however, provides with exact morphological information at any time of the disease. Involvement of both temporal lobes or of one temporal lobe and the anterior commisure is pathognomonic for HSE.

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"TIqE T E M P O R O - M E D I A L HOT SPOT IN I~-PAO SPECT" KEY FINDING IN ACUTE HERPES SIMPLEX ENCEPHALITIS H. H e n k e s *°, G. H u b e r * , J. H i e r h o l z e r °, H. J ~ g e r ~, G. H a ~ n n n ~ , U. P i e p g r a s * Institut fffr Neuroradiologie* und Neurologische Klinik s, U n i v e r s it ~t ski iniken, Homburg/Saar ; Radiologische Klinik°,UNRV/SC, Freie Universit~t Berlin

BRAIN CHANGES AT VARIOUS STAGES OF HIV INFECTION R. Raininko, I. Elovaara, A. Virta, L. Valanne and S.-L. Valle Departments of Diagnostic Radiology and Neurology, University of Helsinki, Aurora Hospital and Kivel~ Hospital, Helsinki, Finland

The prese~Iting syr~toms as well as the CT and MRI findings in HSV encephalitis can be highly indicative for this diagnosis. In a significant number of cases, however, there is no definite diagnosis before brain biopsy, for instance due to inconclusive CSF findings, normal CT scans in the very early phase etc. Early and correct diagnosis is crucial for initiation of appropriate medical therapy. The present paper focusses on 99mTc HM-PAO SPECT findings in HSV encephalitis. Patients and methods: Clinical data and imaging findings of 6 patients, suffering from proved HSV encephalitis were reviewed in retrospect. All patients had undergone state Of the art CT and MRI examinations, including evaluation of regional cerebral blood flow (rCBF) by 99r~pe HM-PAO SPECT. Results: CT revealed temporal lesions with mixed densities in 4 OUt of 6 patients. In 2 patients, initial CT scans w e r e comDletely normal. MR images were superior to CT in (a) demonstrating the systemic involvement of limbic structures, and (b) in showing the hemorrhagic component of the temporal foci. Both findings are confirming the diagnosis of HSV encephalitis. Evaluation of rCBF by 99mTc HM-PAO SPECT disclosed a focally increased rCBF of the affected temporal lobe in all patients during the acute hemorrhagie-neerotizing stage of the disease. In one patient, this focally increased rCBF was accompanied by normal CT and MRI findings, conclusive CSF findings and prompt improvement after initiation of therapy. In conclusion, the evaluation of rCBF by 99~pc HM-PAO SPECT is indicated in all cases with presumed HSV encephalitis. Increased tracer uptake, i.e. increased rCBF in the t emporo-medial r e g i o n gives s t r o n g support to the diagnosis of acute HSV encephalitis.

Effects of HI virus itself on the brain were studied in lOl HIV-infected persons in whom other brain infections or diseases were carefully excluded. 29 of them were asymptomatic (ASX), 35 had lymphadenopathy syndrome (LAS), 17 had AIDS-related complex (ARC) and 20 had AIDS. They underwent Cf and/or MRI (95 CT and 87 MR scans). A control group of 32 HIV-seronegative healthy persons underwent MRI. Atrophic changes were found in 9% of the controls, in 31% of the persons with ASX, 29% with LAS, 59% with ARC, and 70% with AIDS. The changes were bilateral and symmetric. Atrophy was more extensive and more severe at later stages of HIV infection. Infratentorial atrophy was most common at ASX and LAS, but supratentorial atrophy became more pronounced at ARC. Generalized atrophy was typical of AIDS. O n M R I , unspecific small hyperintensities were detected in 13% of the controls and in 6-15% of the HIV-infected groups. Larger diffuse bilateral white matter infiltrations (HIV encephalitis) were found in 4/20 patients with AIDS. All those four patients were demented. Four patients with AIDS and one with LAS had local, often bilateral hyperintensities in the internal capsules, lentiform nuclei or thalami. One ~IDS patient, examined with CT only, had a hypodensity in the lentiform nucleus. Conclusions: Loss of brain parenchyma can occur during an early stage of HIV infection, but the atrophic process becomes more intense at later stages (ARC and AIDS). Parenchymal infiltrations seen as hyperintense areas on MRI are mainly found at AIDS and are usually associated with severe clinical symptoms. Brain changes caused by HIV seem to have a tendency to symmetry.

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PROGRESSIVE DIFFUSE LEUKENCEPHALOPATHY (PDL) I N AIDS - A DISTINCT LESION PATTERN DETECTABLE BY CT AND MRI H. H e n k e s *° , G. H u b e r *, J. A r t i g a s + , R. J o c h e n s °, W. S c h 6 r n e r °, U. P i e p g r a s * Institut f~r Neuroradiologie, Homburg/Sear*; !netitut f~r Pathologic, ArK Berlin+; Radlologische K1inik, UKRV/SC, Freie Universit~t Berlin

C N S - L Y M P H O M A S IN A I D S - P A T I E N T S N E U R O R A D I O L O G Y AND N E U R O P A T H O L O G Y

We report upon a distinct pattern of white matter lesions in AIDS that b y means of CT a n d MRI can definitely be differentiated from other types of CNS involvement in the disease. The clinical appsarance is that of a p r o f o u n d p s y c h o - o r g a n i c syndrome. Patients a n d m e t h o d s : The present study is based o n the c l i n i c a l a n d i n ~ g i n g d a t a of 350 M R I examinations, carried out in 220 patients with C~S raanifestations of the HIV infection. All studies have been performed using 3rd generation CT scanners and a 0.5 T MRI unit. The imaging protocol was in accordance with clinical routine procedures. Results: In 7 AIDS patients, presenting with severe dementia, we observed bilateral-symmetric, confluent white matter lesions, located in the frontal a n d parietal lobe. The a f f e c t e d b r a i n regions were hypodense on CT and hyperintense on T2-WI, without mass effect or contrast enhancement. CT failed in the detection of brain stem involvement (i.e. Wallerian degeneration) that was c l e a r l y v i s i b l e o n MRI. Pathologically, we observed diffuse 10ss of myelin, subcortical invasion of macrophages, vacuoles in the white matter and multinucleated g i a n t cells. Conclusion: For the above described pattern, we propose the acronym "PDL". It can be defined by a c l e a r cut CT a n d MRI a p p e a r a n c e as well as by distinct n e u r o p a t h o l o g i c findings. Most probably, this pattern represents a rare, severe variant of HIV leukoencephalopathy.

J. B e r k e f e l d ,

H. Hacker,

W. S c h l o t e

The CT- and M R I - M o r p h o l o g y of 30 cases with C N S - l y m p h o m a s in A I D S - p a t i e n t s was r e v i e w e d and c o m p a r e d w i t h h i s t o l o g i c a l f i n d i n g s . S u r p r i s i n g l y CT and MRI s h o w e d a b r i g h t s p e c t r u m of a p p e a r a n c e s r a n g i n g f r o m solid, n o d u l a r t u m o r s to n e c r o t i c m a s s e s and very i r r e g u l a r t y p e s of s p r e a d i n g , w h i c h can m i m i c g l i o b l a s t o m a or e n c e p h a l i t i s . M e t a s t a t i c s p r e a d i n g a l o n g the C S F - s p a c e s could be p r o v e n by g a d o l i n i u m e n h a n c e d MRI in 3 cases. The d i f f e r e n t t y p e s of t u m o r morphology found by i m a g i n g m o d a l i t i e s , showed a good c o r r e s p o n d a n c e to h i s t o l o g i c a l findings, w h e r e r e g u l a r p a t t e r n s of t u m o r g r o w t h could be d i s t i n g u i s h e d from "wild" and i n f i l t r a t i n g t y p e s of s p r e a d i n g . The i n v a s i o n of the m e n i n g e s and t h e C S F - s p a c e s could also be c o n f i r m e d by n e u r o p a t h o l o g y .

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NATURAL HISTORY OF CYSTICERCOSIS ON NEUROIMAGING CS Zee, S D e s t i a n , J A h m a d i , H D S e g a l l U S C S c h o o l of M e d i c i n e

GIQ~nF CET4EEA%~L ~ O ~ $ e ~ CASES

Purpose: To E v a l u a t e the n a t u r a l h i s t o r y of n e u r o c y s t i c e r c o s i s and c o m p a r e the efficacy of various imaging modalities. M a t e r i a l and M e t h o d : A t o t a l of 212 p a t i e n t s with neurocysticercosis were evaluated. Their neuroimaging studies, clinical information at t i m e i n t e r v a l s b e t w e e n 4 w e e k s to 4 years were examined. F i n d i n g s : MRI and CT are c o m p a r a b l e in the detection of parenchymal lesions in v e s i c u l a r stage. MRI with G d - e n h a n c e m e n t is m o r e sensitive than conventional MRI or CT for parenchymal lesions in colloidal vesicular and g r a n u l a r n o d u l a r stage. CT is s u p e r i o r for p a r e n c h y m a l l e s i o n s in n o d u l a r c a l c i f i e d stage. Intraventricular cysts c a n be life t h r e a t ening and e a r l y d e t e c t i o n is m a n d a t o r y . MRI with Gd-enhancement appears to be t h e noninvasive modality of c h o i c e . However, in some cases, a definitive diagnosis can only be obtained with CT v e n t r i c u l o g r a m . MRI is t h e noninvasive imaging modality of c h o i c e for cist e r n a l a n d s p i n a l cysts. A r a c h n o i d i t i s s e c o n dary to c i s t e r n a l and s p i n a l c y s t s is better d e m o n s t r a t e d w i t h G d - e n h a n c e d MRI. C o n c l u s i o n : It is i m p o r t a n t to r e c o g n i z e the n a t u r a l h i s t o r y of n e u r o c y s t i c e r c o s i s . Various imaging modality may be needed to evaluate patients with neurocysticercosis. MRI s h o u l d be primary imaging modality. Appropriate treatment planning can be derived only from a thorough understanding of natural history of neurocysticercosis.

C. Lang,

-- CT v5 MR - Ab~LYSIS OF 21

A. Kohli, ~S.B. De:_ai, V.C. Shah, O.J. Tayri, P. Rao Breach Cer~,/ Hospital ~, Research Cxent~, Bombay, India ~Jaslok Hospital & .Rzc~_c:rchC~:~t~ Bombay, India Twentvo-,e patients with Total epilepsy ~id/or signs of raieed intracranial tension were studied with CT Scans. In Sixteen patients, parallel MRI stL~ies were also obtained. Patients were studied on Hitachi W-7(~ and Siemens EEI~ATOM DR-3 CT scanners. In all, both pre and post contrast CT stLdies were ci~ained. MRIs were done on i.O TESTA Siemens M~%GNETOM supercondt~tir@ magnet. Both T1 and T2 weighted spirr4mcho images were obtained. In few Gadolini~e, enhanced MRIs were dc~e. Giant %i~berculceas were ~ on CT scan as iso to mildly b/#erdense well defined rite,--likeenhancing mass lesions with ~_~-eundir~ oedema ard mimic Slic~s. Or, MR. all these lesions were seen to be iso to hy~o interne an Ti weighted images and appeared me~-kedly hypo intense on T2 weighted images. All the=Je l~_ions ~ r ~ = d greater than 2.(~m in size. In three patients, the lesio-,s tc~Lally r e = ~ to anti-tuberc~_dc~s bhera~y. In other 18, the lesions were ex'cised to e>:cl~de glioma. Thus we cor~Itde that MR imaging is necessa~; for the differentiaticr, of giant tuberculomas from g l i ~ to prevent surgical intervention.

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98 AN ASYMPTOMATIC DURAL FISTULA, RELATED TO AN INFECTION BY BORRELIA BURGDORFERI P.H.HOOGLAND , M.C.SCHOEMAKER, J.A.VEENENDAAL -HILBERS, W.V.M. PERQUIN, L.DOORNBOS The authors present 2 cases in which a meningovasculitis and an occlusion of the basilar artery were found, caused by a Borrelia Burgdorferi infection. Both patients had neurological symptoms, related to an angiographically demonstrated basilar artery occlusion. The C.S.F. showed specific antibodies against Borrelia Burgdorferi. In one patient a control angiography after antibiotic treatment showed complete recovery of both the occlusion and the vasculitis of the vertebro-basilar system, but also the development of an asymptomatic dural fistula to the transverse sinus with subsequent spontaneous recovery. We therefore conclude that: a basilar artery occlusion, in these cases caused by a meningo-vasculitis by Borrelia Burgdorferi can be a reversible process. - dural fistulae can also develop secondary to an arterial occlusion - dural fistulae can be totally asymptomatic. - Borrelia Burgdorferi infections (" Lyme disease") can involve both the central and peripheral nervous system; the designation "Neuroborreliosis" seems appropriate. -

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Concurrent Scientific Session: Imaging Techniques: MRI, CT Moderators: J.M. Caill6, Bordeaux, France and U. Piepgras, Homburg, Germany 04.30 pm-05.40 pm

Scientific Papers 99-106

05.45 pm - 07.15 pm (Main Hall)

General Assembly ESNR

04.30 pm-05.40 pm Scientific Papers 99-106 099 Can the published literature be utilised in the choice of acquisition parameters in MRI?

103 Texture Analysis: A new tool in brain magnetic resonance imaging

G.H. du Boulay, B.A. Dando, D.P. Kingsley, B.A. Teather, D. Teather, London/Leicester, United Kingdom 100 Fast imaging in brain MR diagnostic algorithm

E Di Salle, S. Cirillo, M. Cesarelli, A. Pepino, L. Simonetti, M. Bracale, R. E1efante, E Smaltino, Naples, Italy 104 Postmortem MRI of brains in vitro: Correlation with histo-pathoiogical and neuroradiologicai findings

E Di SAID, S. CiriUo, L. Simonetti, E Briganti, E Golia, R. Elefante, E Smaltino, Naples, Italy 101 Comparison of T2-weighted fast spin-echo sequences with conventional sequences in neuro MR imaging and in a phantom G. Sze, M. Merriam, New Haven, USA t02

Differentiation and characterisation of normal and pathological brain tissue in MRI by use of a histogram

based cluster analysis (relaxometry) J. Reul, H. Handels, A. Thron, R. Herpers, Ch. Lakenberg, T. Tolxdorff, Aachen, Germany

E Angeleri, L. Chiaramoni, k Diamanti, N. Foschi, M. Maricotti, A.M. Mauro, U. Salvolini, M. Scapelli, Ancona, Italy 105

"Curved planes" a further improvement of CT morphological analysis M. Leonardi, A. Righini, R. Agati, G. Brayda, Udine/ Bologna, Italy

106 Digital subtraction cisternography and MR cisternography in cerebrospinal fluid rhinorrhoea A.K. Wakhloo, M. Schumacher V. van Velthoven, Freiburg, Germany

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CAN THE PUBLISHED LITERATURE BE UTILISED IN THE CHOICE OF ACQUISITION PARAMETERS IN MRI ?

FAST I M A G I N G IN B R A I N M R D I A G N O S T I C A L G O R I T H M F.Di Salle, S.Cirillo, L . S i m o n e t t i , F. B r i g a n t i F.Golia, R.Elefante, F . S m a l t i n o U n i v e r s i t y of Naples, II F a c u l t y of M e d i c i n e

G H du Boulay t , B A. Dando2, D P Kingsley 1, B A Teatherz and D Teatherz 1. Institute of Neurology, Queen Square, London, England 2. Dept. Mathematical Sciences, Leicester Polytechnic, Leicester, England This collaborative research study, funded in part by the Department of Healtb(UK), seeks to develop a prototype computer system to advise on selection, on the basis of clinical history, signs and symptoms, of image acquisition parameters best suited to the neuroradiological problem. Sources of knowledge utilised in system construction include protocols from experienced imaging centres, expert mdiological opinion, statistical data derived from an extensive image archive and a detailed review of published literature on MRI in cerebral disease over a two year period beginning January 1989. We have sought to charaetedse the image sequences studied in terms of a limited number of meaningful features (TI-, T2-, T2*-, proton density-weighting, acquisition matrix, slice thickness, flow sensitivity etc) and from the literature to relate these to the ability of the sequence to aid in the solution of different problems such as demonstration of a particular disease, differentiation between diseases, demonstration of surrounding anatomy and extent of lesion. Crucial steps in combining published data are the creation of generally applicable scales of measurement of sequence characteristics and ratings for success in solving clinical problems. Stumbling blocks are missing data and incomplete specifications of sequences. Very few papers fully answer the questions they address.

The role of Fast I m a g i n g in N e u r o r a d i o l o g i c d i a g n o s t i c a l g o r i t h m is examined, in c o m p a r i s o n w i t h Spin-Echo and I n v e r s i o n R e c o v e r y images. This e v a l u a t i o n has b e e n p e r f o r m e d in a large p a t i e n t sample, c o m p r e h e n s i v e of the m a i n b r a i n pathologies, w i t h r e g a r d to the s e n s i t i v i t y in the i d e n t i f i c a t i o n of lesions, the c o n t r a s t b e t w e e n normal b r a i n and p a t h o l o g i c t i s s u e s a n d the r e c o g n i t i o n of l e s i o n t i s s u e components. The "in vivo" d a t a h a v e b e e n a n a l y s e d on the basis of "in vitro" e x p e r i m e n t s c a r r i e d out b y means of test objects w i t h w e l l - k n o w n r e l a x o m e tric characteristics. The r e l a t i o n s h i p b e t w e e n signal i n t e n s i t y and tissue parameters in S p i n - e c h o and Fast i m a g i n g has b e e n evaluated: the less r e g u l a r c o r r e l a t i o n found in Fast sequences lowers t h e i r s e n s i t i v i t y towards a w i d e s p e c t r u m of b r a i n p a t h o l o g i c m o d i f i c a t i o n s and limits t h e i r c l i n i c a l utility. ~ast sequences, however, e x h i b i t an h i g h sensit i v i t y to m a g n e t i c field d i s o m o g e n e i t y a n d t h e y are of choise for the d e t e c t i o n of c a v e r n o m a s and haemorrhage. A c c o r d i n g to our o p i n i o n Fast sequences, b o t h T1 and T2 weighted, s h o u l d be i n c l u d e d in b r a i n M R d i a g n o s t i c algorithm, but t h e y c a n n o t r e p l a c e the homologous SE and IR scans.

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COMPARISON OF T2-W~IGHTED FAST SPIN-ECHO SEQUENCES WITH CONVENTIONAL SEQUENCES IN NEURO ME IMAGING AND IN A PHANTOM G. Sze, M. Merriam Yale University School of Medicine

D I F F E R E N T I A T I O N A N D C H A R A C T E R I S A T I O N OF N O R M A L A N D P A T H O L O G I C A L BRAIN T I S S U E IN MRI BY U S E OF A HISTOGRAM BASED CLUSTER ANALYSIS (RELAXOMETRY) J. R e u l *, H. H a n d e l s **, A. T h r o n *, R. H e r p e r s **, Ch. L a k e n b e r g *, T. T o l x d o r f f ** N e u r o r a d i o l o g i e * u n d M e d i z i n . I n f o r m a t i k **, K l i n i k u m R W T H A a c h e n , P a u w e l s s t r a ~ e 30, 5 1 0 0 Aachen

PURPOSE: To compare T2-weighted fast spin-echo (FSE) MR with conventional sequences in imaging of the brain and spine and to optimize FSE parameters in a phantom. MATERIALS AND METHODS: Fifty patients with pathology of the brain and 50 patients with pathology of the spine were imaged on 1.5 T magnets with T2-weighted FSE and long TR spin-echo (SE) sequences or, in the spine, with multi-slice gradient echo (GE) sequences. The FSE sequences conslsted of a 90 RF pulse followed by a train of 4 £o 16 echoes. Parameters were TR 2000/TE 17-153, with imaging times of 2 to 3 minutes. The conventional sequences were performed with routine parameters and cardiac gating, flow compensation techniques where appropriate. To study optimization of parameters of the FSE sequence, a phantom of agar was created, with "lesions" embedded. Variations of E-space and echo train length were tested. RESULTS: In all clinical cases, FSE image quality was equal or superior to long TR SE or multi-sllce GE images, with equal sensitivity and pathology detection. Pathology was varied including tumor, infection, demyelinating, ischemie, and degenerative change. The phantom model showed that optimization of image quality was obtained with increased echo train lengths and decreased E-space. Increasing unsharpness was noted with increasing E-space, but no loss of lesions was seen when parameters were optimized. CONCLUSION: Compared with long TR SE or multi-slice GE images, FSE images are acquired in less time (less than 3 minutes), with equal or superior image quality and equal sensitivity in detection of pathology. FSE techniques promise to replace both T2-weighted SE and GE techniques in neuro MR imaging. •

o

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A i m of t h e s t u d y w a s t h e d i f f e r e n t i a t i o n and c l a s s i f i c a t i o n of normal and p a t h o l o g i c a l brain tissue in MRI by the use of a new s e g m e n t a t i o n m e t h o d b a s e d on m u l t i d i m e n s i o n a l M R - p a r a m e t e r histograms. Multiexponential T 1 u n d T2 a n a l y s i s w a s developed with a specially designed software to g e t t h e r e l a x a t i o n v a l u e o f e v e r y p i x e l . The histogram based segmentation algorithm l e a d s to a u t o m a t i c t i s s u e d i f f e r e n t i a t i o n b y using clustering techniques. The received cluster were colour-coded and correlated to t h e n o r m a l s p i n e c h o slice. W e e x a m i n e d 12 normal volunteers and 55 patients with n e o p l a s t i c and other lesions (18 meningeomas, 6 astrocytomas, 13 glioblastomas, 2 adenomas, 8 m e t a s t a s e s - all v e r y f i e d h i s t o l o g i c a l l y ) . By our s o f t w a r e - s y s t e m e v e r y n e w m e a s u r e m e n t s c o u l d be c o m p a r e d w i t h the a v a i l a b l e data and identified. Reliable differentiation and identification of normal brain tissue is possible, s o m e t i m e s b e t t e r than on the n o r m a l M R - s l i c e . A l s o i d e n t i f i c a t i o n of m e n i n g e o m a s c o u l d be d o n e w i t h h i g h accuracy. I d e n t i f i c a t i o n of o t h e r t i s s u e s is s t i l l difficult but should be possible with i n c r e a s i n g n u m b e r s in the d a t a b a s e . In s u m m a r y this method could be a useful tool for preoperative identification and differentiation

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T E X T U R E A N A L Y S I S : A N E W T O O L IN B R A I N M A G N E T I C RESONANCE IMAGING. F . D i Salle, S . C i r i l l o , M . C e s a r e l l i , A . P e p i n o , L.Simonetti, M.Bracale, R.Elefante, F.Smaltino U n i v e r s i t y of N a p l e s , II F a c u l t y of M e d i c i n e

POSTMORTEM MRI OF BRAINS IN VITRO: CORRELATION WITH HISTOPATHOLOGICAL AND NEURORADIOLOGICAL FINDINGS. Angeleri F., Chiaramoni L., Diamanti L , Foschi N., Mariootti M., Mauro A.M, Salvolini U., Scarpelli M. Magnetic Resonance and Institute of Morbid Anatomy University of Ancona - Italy.

MRI s i g n a l i n t e n s i t y s h o w s a m u l t i p a r a m e t r i c correlation with tissue molecular composition p r o v i d i n g m u l t i p l e r e l i a b l e t o o l s for the i d e n t i f i c a t i o n of n o r m a l and p a t h o l o g i c components, and producing a very high efficacy in t i s s u e c h a r a c t e r i z a t i o n . In s p i t e of M R I e f f i c a c y i n d i s c r i m i n a t i n g t i s s u e s it is n o t u n c o m m o n t o e x p e r i e n c e s i t u a t i o n s in w h i c h M R I d o e s not p r o v i d e a c o m p l e t e i d e n t i f i c a t i o n of lesions. W h i l e a c o r r e c t d e f i n i t i o n of l e s i o n t o p o g r a p h y is u s u a l l y o b t a i n e d w i t h a v e r y p r e c i s e p r e - s u r g i c a l p r o g r a m m a t i o n , it is n o t always possible an histological identification l e a d i n g u p to an e x a c t d i f f e r e n t i a l d i a g n o s i s . A n a d d i t i o n a l t o o l in t i s s u e c h a r a c t e r i z a t i o n can be obtained through post-acquisition image analysis techniques. Useful information about t i s s u e s t r u c t u r e c a n b e p r o d u c e d b y m e a n s of a t e x t u r e a n a l y s i s a n d a p a t t e r n r e c o g n i t i o n system. This information can be used to generate a r t i f i c i a l t e x t u r e - w e i g h t e d i m a g e s in w h i c h p i xel i n t e n s i t y is b a s e d o n t e x t u r e f e a t u r e s . The A u t h o r s p r e s e n t t h e i r m e t h o d for t e x t u r e a n a l y sis a n d its a p p l i c a t i o n to "in v i t r o " t i s s u e simulating objects and to normal and pathologic "in v i v o " images. T h e a d v a n t a g e s of t h i s i m a g e p r o c e s s i n g , a r e d i s c u s s e d in c o m p a r i s o n w i t h t r a d i t i o n a l p r e a n d p o s t - c o n t r a s t M R images.

MRI was used for the post-mortem study of 30 formalinfixed brains in order to correlate neuropathological and radiological findings. Only brains obtained from patients older than 60 years of age and without signs or symptoms of neurological diseases were used in the study. The brains were immediately fixed in 10% neutral formalin for 2-3 weeks and washed in tap water for a minimum of three hours before MRI. The exam was performed with the brain placed in a plastic box completely filled with water. Both the whole brain and slices were examined in each case. A Magnetom Siemens 1.0T. unit was used for MRI. The MRI technique included Spin-Echo 2D standard sequences and Gradient-Echo 3D technique with multiplanar and surface reconstruction in post-processing. The value of this approach in the discrimination between normal and pathological findings are stressed as well as the technical problems encountered in the study.

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"CURVED PLANES": A FURTHER IMPROVEMENT OF CT MORPHOLOGICAL ANALYSIS M. Leonardi, A. Righini, R. Agati*, G. Brayda** Servlzi di Neuroradiologia dell'Ospedale Civile di Udine e della *Clinica Neurologica dell'Universita' di Bologna **Casa di Cura "Madre F. Toniolo"; Bologna

DIGITAL SUBIRACTION CISTERNOGRAPHY AND MR CISTERNOeRAF~Y IN CEREBROSPINAL FLUID RHINORRHOEA

The new software available on the Elscint CT Systems Exel allows a particular computer reformation of selected sections= the "curved planes". This option was designed to fit the study of the jaw, to allow a deeper analysis of cortical mandibular bone for implants and is based on the possibility of planar reformation of the jaw (something like an x-ray orthopantomography). The same mathematical approach, with a "simple" modification offers the identification of any curved plane selected and its reformation on a planar base= from the globe to the map of the world. In fact no straigth plane is really identifiable in the human body, even the word we use to name the CT images is evocative of the straight knife kut of the anatomist: "cut" or "section" or "slice". Something linear which will allow us to go inside the anatomy, but modifying, cutting the anatomical structures. The curved plane locks extremely different= it allows us to follow the curved surfaces of our antomy and to reconstruct it in a planar presentation to allow us a better understanding. A few examples will be presented= the study of the posterior foramen lacerum or jugularis; the study of the facial canal with all its bending and kinking and with the stapedial canal going upward and backward; the study of the optic nerves, chiasma and optic tracts.

AK Wakhtoo 1,M Schumacher 1,V van Veithoven 2 Section of Neuroradiology and Department of Neurosurge~,, University of Freiburg Exact preoperative localization of dural defect in CSF rhicorrhoes is required for surgical planning. Digital subtraction cisternogn;phy (DSC) was performed 21 times in 19 patients with CSF rhinorrhoea and 1 patient with otorrhoes, The investigation was carried out on a OSA unit. After C1/C2 puncture using a 22-gauge spinal needle, about 8 rnl of non-ionic contrast agent (250 mg t/rot) were injected intrathecally under rea~-Ume digital subtraction fluoroscopy at a rate of 12.5 pictures/see, A dural tesion could be shown in 9 of 12 cases with ast~e CSF leakage, In 3 cases the frontal subarachnoid space did not yield sufficient contrast due to e prefixed chiesm, traumatic hematorna of the interpeduneuier cistern and arachnoid adhesions. Out of 8 patients with suspected leakage and CSF rhinorrhoea in non-drop period, DSC could reveal s dural defect in only 2 cases after increasing the CSF pressure artificially by injecting 10 ml of saline solution. The investigation was followed by CT cietemography defining the lesion in the coronal view. In two cases the CT failed to identify the dural defect. in 7 patients heavily T2-weighted MR investigation (RARE. Rapid Acquisition with Relaxation Enhancement) was performed, The CSF path could be traced in 4 cases with severe CSF rhinorrhoea. In 9 of 11 cases the preoperative DSC findings were confirmed surgically: in 7 cases the dural defect was in the cdbriform plate; 4 cases involved the frontat part of sells, tuberculum seliee and p~anum sphencidale; in 3 cases the dural defect was located in the middle fosse. CSF rhinorThoea ceased in air operated patients (14) bat one, DSC combined with artil~dal increase of CSF pressure can be recommended in diagnosing CSF rhinorrhoea. However, CT cistemography still remains the most sensitive method for detecting an osseous defect. Being a non-invas~e technique the preoperative diagnostic shouId start with a heavily T2-weighted MR investigation.

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Scientific Session: Cerebrovascular Disease - 1 Moderators: P. Lasjaunias, Paris, France and U. Salvolini, Ancona, Italy 08.30 a m - 10.30 am

Scientific Papers 1 0 7 - I22

10.30 a m - 11.00 am

Coffee Break

08.30 am-lO.30 am Scientific Papers 107-122 107 North American symptomatic carotid endarterectomy study: Value of endarterectomy for severe stenosis (70-99°70)

116 MRI-Morphology and classification of cerebral cavernomas S. Schefer, A. Valavanis, W. Wichmann, Zurich, Switzerland

A. J. Fox, H. J. M. Barnett, S.J. Peerless, London, Canada 108 Longitudinal MR study of cerebral infarcts with infusion

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S.W. Horowitz, S.R. Gupta, J.C. Maggio, Maywood, USA 109 Long term MRI follow-up after MCA occlusion in the rat compared to MCA infarction in the man. GD-DTPA

118

Occurrence, location, and CT-characteristics of silent stroke

1t9

W.P. Sanders, P.A. Sorek, B.A. Mehta, Detroit, USA 114 The investigations of unexplained intraeerebral hematomas: The role of MRI and delayed angiography K.G. terBrugge, R.A. WiUinksy, P. Fitzgerald, W. Montanera, C. Wallace, Toronto, Canada 115 Association of cerebral so-called venous angiomas with cryptic vessel malformations G. Huber, M. Hermes, H. Henkes, U. Piepgras, Homburg/Saar, Germany

Pediatric Sturge-Weber disease - Detection of leptomeningeal angiomatosis by Gd-DTPA enhanced MRI

Intracranial dural arteriovenous shunts causing venous congestive encephalopathy

120 MR imaging in cerebral venous thrombosis: 24 cases with angiographic correlation D. Dormont, S. Evrard, J. Chiras, C. Marsault, Paris, France 121 Cerebral sinus thrombosis and MRI

S.P. Lownie, A.J. Fox, C.G. Drake, London, Canada 113 Fenestration of intracerebral arteries and associated anomalies

venous disorder?

K.G. terBrugge, L.N. de TiUy, W.J. Montanera, R. A. Willinsky, M.C. Wallace, Toronto, Canada

S. Lang, M. Brainin, E. Pauly, A. Seiser, B. Czvitkovits, J. Dastmattschi, Klosterneuburg, Austria 112 Spontaneous dissections of the basilar artery

a

H. Henkes, G. Huber, R. Bittner, J. Sperner, N. Heye, U. Piepgras, Homburg/Berlin, Germany

H. Becket, B. Haubitz, K. Holl, N. Nemati, M.R. Gaab, H. Dietz, Hannover, Germany 111

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U. Piepgras, G. Huber, H. Henkes, Homburg/Saar, Germany

K.-A. Thuomas, Z. Kotwica, P. Dimopoulos, K. Bergstr6m, L. Persson, Uppsala, Sweden 110 Angiographic findings in reduced cerebrovascular reserve capacity

Sturge-Weber disease

J. Reul, Ch. Isensee, A. Thron, H.B. Gehl, Aachen, Germany i22

Venous sinus thrombosis: Magnetic resonance angiography (MRA) in diagnosis and follow up B. Ostertun, L. Solymosi, W. Kaiser, M. Reiser, Bonn, Germany

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10"7 NORTH AMERICAN SYMPTOMATIC CAROTID ENDARTERECTOMY STUDY: VALUE OF ENDARTERECTOMY FOR SEVERE STENOSIS (70-99%) AJ Fox, HJM Barnett, S~ Peerless for the NASCET Group, London, Canada PURPOSE: To verify efficacy of endartereetomy for carotid stenosis causing ischemia or infarction. MATERIALS AND METHODS: This randomized multicenter trial ofmedieal therapy versus medical therapy follow. ing endartereetomy accepts patients symptomatic within 120 days and with angio verifying stenosis of at least 30%. The plan was to follow patients for a mean of 5 years. End points are stroke and death. At intervals, two methodologists analyze results, and report to an NIH Monitoring Committee. RESULTS: It has been reported to the Monitoring Committee that, with 659 patients with severe (70-99%) stenosis, followed for a mean of 18 months, stroke occurred in the medical group more than 3 times as often as after surgery, implementing the trial's stopping rules. For both scientific and ethical reasons the severe (70-99%) stenosis part of the study was stopped. CONCLUSIONS: 1) Carotid endartereetomy is highly effee. live to prevent stroke for patients with recent iscbemia and severe (70-99%) stenosis. 2) Diameters from anglo were measured: the narrowest stenosis diameter compared to the normal carotid beyond the bulb. 3) NASCET continues for moderate (30-69%) stenosis.

108 L(ANGITUDINAL MR STUDY C~ CEREBRAL INFARCTS WITH INFUSION. S.W. Horowitz, S.R. Gupta, J.C. Maggio Loyola University Medical Center and Hines V.A. Hospital Purpose: To determine the utility of contrast infusion in MR of cerebral infarction. Methods: CVA patients were studied by serial M R with and~ - ~ t infusion of Gd DTPA 0.i mmol/kg. Three MR scans were performed at 2-8 days, 9-10 days, and 4-6 weeks post-ictus. Pesults: Incidence of enhancement was 43%, 95%, and 77% f o r - - ~ time periods. Incidence, degree and area of enhancement was greatest at 9-19 days. In 2nd to 3rd week post-ictus, infusion ~ detected CVA in 7 patients in ~h~m non-contrast M R was isointense. Parenchymal enhancement occurred in a smaller peroentage of deep infarcts ~30%, 90%, 50% for 3 periods) than in hemispheric infarcts (80%, 100%, 100%). Non-oontrast T2w M R had greatest sensitivity in detection of CVA at 2-8 days, however, ccntrast infusion penmitted differentiation of new from old infarcts in 5 patients. Conclusion: Contrast infusion with Gd DTPA increases the sensitivity of M R in detection of ne~ infarcts in the first 3 weeks. Incidence of enhanoement is less in deep infarcts cc~pared with hemispheric CVA but enhancement was maximal at 9-19 days in both groups.

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LONG TER~ MRI ~OL~OW-UP AFTER MCA OCCLUSION IN THE RAT COMPARED TO NCA INFARCTION IN TH~ MAW.G~-DTPA.

ANGIOGRAPHIC FINDINGS IN REDUCED CEREBROVASCUI~R RESERVE CAPACITY H. Becket*, B. Haubitz*, K. Hell**, N. Nemati**, M. R. Gaab**, H. Dietz** *Department of Neuroradiology, **Department of Neurosurgery, Medical School Hannover, Germany

LoPersson. Departments of Diagnostic Radiology an~ ~eurosurgery~Urrivers~t~y~ospi%al~Uppsala~Swe~e~ Purpose, To follow %~e develepmen~ of oedema an~ b~ood-~rafn ~arrier permea~il~%y%e ~d-DTPA I~ expe-r~menSal isohemlc i~farctlon ~n r~ts and i~ h u m a ~ M C A Infarction. ~euroloE~eal outcome end ~Istopa%hole~°

Ma~er~al ~ Me%~od.MRI wa~ ¢ ~ r r i ~ out i~ I0 p~%~en~s w~t5 complete MCA occlusion and in 55 Sprague~ w l e y r~%s w~%h surgical MCA occlusion.5 s~am oper~vted rm~s were also exsmine~. The ra~s were followed, MRI and ~enrological ~ee%~g, for 6 weeks s%~r%~g 2 ~ O ~ S after surEe1~% The p ~ $ e n ~ s were MR e x s ~ n e d w ~ % ~ m 2 Aours ~fter the el~m/eal infarct~o~ d ~ a ~ o s~s a ~ fol~ow~ ~ i l 6 weeks ai~er %~e CVL. The rats and the patients ~o% G~-DTPA ~% each MR examination. Results. T~e i r ~ r o % size and %he oha~ges ~ % ~ m e not~ee~l i~ %he s~ze of %he ~psilateral hemisphere ~ r eed between the r~ts ~ d the patten%s, T~e disruption of the brain-b~rrier~as s h 0 w n % y C~I-DTPA, ar~ development of ~%~PY~7 also w e ~ I ~ g o o d affreem~z~ i n h u m a n and i ~ r a t . The infarc~ s~ne was bes~ visualized ~y eonseoutive snBtract~om of the l~s% e~hee~ from %he

~/~o~s). C ~ l ~ s ~ o ~ : The fecal ~schemic changes prod~oecl ~ r M~A oeclus~o~ cor~s%~%~r~es ~ dynamic process where several pathophysioleg~eal events occur over an ex~ended perio~ of t~me° The rat model seems to Be useful for eve l u a ~ o ~ of various ~n~--~sc~em~c therapies,

The results of cerebral angiography were compared to Stable-Xenon-CT in 38 patients with a reduced cerebrovascular reserve capacity (CVRC). Stable-Xenon-CT is aa effective method of measuring cerebral blood flow (CBF)o It allows the calculation of flow-map images, and after the application of I g acetazolamide (Dis~noxR) it also gives the opportunity to measure the CVRC. A reduced CVRC indicates a hemodynamic insufficiency. In this way it is possible to differentiate between a thrombembollc and a hemodynamic cause of cerebrovascular disease. Before the introduction of Stable-Xenon-CT, cerebral angiography was considered to be a useful procedure for differentiating between both. The aim of this study was to prove which angiographic findings can be found in patients with a reduced CVEC. We found that 69% of the patients exhibited vascular occlusion. Most of these had a combination of an occlused internal carotid artery on one side and stenosis of the internal carotid artery on the other side. One vessel stenoses and multiple vessel stenoses were seen in 16% in each group only. In contrast we have observed patients with an occluded vessel of one side and a stenosis on the other side, who showed a normal CBF at rest and a normal CVRC. Cerebral angiography alone is not able to detect hemodynamic insufficiency. Stable-Xenon-CT provides important information that is not obtained by angiography, and may be especially useful for planning therapy (e. g. extra-intra-cranial bypass surgery).

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11i OCCURRENCE, LOCATION, AND CHARAUrERIb"rlCS OF SILENT STROKE.

112 CT-

Sabine Lang (1), M.Brainln (1,2), E.Panly (2), A.Seiser

(1), B. Czvitkovits (2), J.Dastmaltschi (2) (1) Department of Neurology, LandesnervenklinJk Gugging, A-3400 Klosterneuburg, Austria (2). Institute for Stroke Research and Stroke Prevention, NO.Wissenschaftliche Landesakademie, A-3500 Krems, Austria Previous brain infarctions seen by means of CT are common in the absence of a history of stroke. 12% of patients (57/476) without a history of a prior stroke had ischemic lesions on their first CT, unrelated to the presenting stroke. The files of the Klostemeuburg Stroke Data Bank (a singie-eenter hospital-based stroke registry) were reviewed to determine the occurrence, location, and CT characteristics of silent/unreported stroke events. The CT lesions were registered by means of a pretested documentation with a high interrater reliability. Most frequent were small deep infarctions (28 cases). Others were infarctions involving areas of the cortex (5), borderzone areas (7), incomplete territorial infarctions (3), deep, large infarctions (2), and infratentorial, bilateral or median lesions (13). Most locations were in brain regions known to harbour silent lesions. No association with known risk factors was found for this group with silent/unreported stroke when compared to the group with single lesions that were related to the presenting stroke.

PURPOSE: To analyze the clinical presentation and natural history of basilar artery dissection. MATERIALS & METHODS: Over the past 15 years, 9 cases of spontaneous dissection of the basilar artery have been encountered. Two of these were bland dissections, presenting with brainstem and/or cerebral infarction. Seven patients presented with subaraclmoid hemorrhage (SAIl) due to a dissecting aneurysm. RESULTS: Of the bland dissections, 1 patient died and 1 survived. Of these with SAIl, 4 survived and 3 died. Re,dew of the cases of bland dissection, in combination with cases from the literature, yielded a total of 15 cases. The patients were young (average age 32 years), usually male (73%), and most had a poor outcome. Those presenting with SAH (a total of 11 cases including the literature) also tended to be young (mean age 43 years), but were more often female (80%), and tended to have predisposing conditions such as hypertension, diabetes or a history of smoking. The difference in the sex distribution between hemorrhagic versus bland dissections was statistically significant (0.025). Of the patients with SAIl, rebleeding occurred in only 1 case. Overall survival was related to the presence or absence of brainstem infarction, the length of the dissection, and the tendency for rebleeding.

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113 FENESTRATION OF INTRACEREBRAL ARTERIES ASSOCIATED ANOMALIES W P S a n d e r s , P A Sorek, B A M e h t a

SPONTANEOUS DISSECTIONS OF THE BASILAR ARTERY SP Lownie, AJ Fox, CG Drake, University Hospital, London, Canada

AND

Purpose: T o r e v i e w a n g i o g r a m s o f 35 patients with fenestration of cranial arteries, with particular attention to associated aneurysms and other anomalies. Methods: Retrospective review of reports of 4836 cerebral angiograms over a 5 year period y i e l d i n g 35 p a t i e n t s w i t h 36 a r t e r i a l fenestrations. These angiograms were carefully examined for the site of fenestration, the presence of aneurysms or other anomalies. Results: T h e r e w e r e 36 f e n e s t r a t e d a r t e r i e s : 16 b a s i l a r , i0 v e r t e b r a l , 8 m i d d l e cerebral, and 2 anterior cerebral, six p a t i e n t s h a d a t o t a l o f 12 a n e u r y s m s , a l t h o u g h only 2 were directly associated with a fenestration, one mid and one distal basilar. T h e o t h e r a n e u r y s m c a s e s h a d f e n e s t r a t i o n s as incidental findings. There were 2 patients with azygous anterior cerebral arteries, one dural AVM of the cavernous sinus and one extracranial A-V fistula. Conclusion: Our data suggests that the i n c i d e n c e o f a n e u r y s m w i t h f e n e s t r a t i o n s is a p p r o x i m a t e l y 5%, w h i c h is s i m i l a r t o m o s t of t h e a u t o p s y series, a l t h o u g h m u c h l e s s t h a n a previous surgical series. As the histologic a p p e a r a n c e o f a f e n e s t r a t i o n is s i m i l a r t o a n o r m a l b i f u r c a t i o n , it m a y b e t h a t a n e u r y s m f o r m a t i o n a t f e n e s t r a t i o n is s i m i l a r to o t h e r Circle of Willis aneurysms, without unusual risk of aneurysm compared to normal bifurcations.

THE INVESTIGATIONS OF UNEXPLAINED INTRACEREBRAL HEMATOMAS: THE ROLE OF MRI AND DELAYED ANGIOGRAPHY. K.G. terBrugge, R.A. Willinsky, P. Fitzgerald, W. Montanera, C. Wallace. The Toronto Hospital - The Western Division Based on a retrospective review of I0 patients with cerebral micro arteriovenous malformations (AVMs) (nidus less than 1 cm) an imaging algorithm for the investigati~ of unexplained intracerebral hematomas (ICH) can be proposed. There were 9 males and i female with a mean age of 40 years. 8 patients had MRI and a vascular abnormality was evident in 2. Angiography established the diagnosis of a micro AVM in all cases. In 3 patients, initial angiography was negative, but followup angiography six weeks or later showed the malformation. We propose the following approach to unexplained ICHs. After CT establishes the presence of an ICH, angiography should be done. A micro AVM or other vascular etiology may be found. If the initial angiogram is negative a baseline MRI may reveal an underlying mass or suggest a cavernoma. If the cause for the ICH is still not clear a followup MRI at 6-8 weeks is recommended. At this time the hematoma will have resolved and the presence of a cavernoma may be clear. If a hemosiderin cleft is seen then a followup angiogram should 5e done. A search for micro AVMs in the face of an ICH is important since they are treatable and can remain undiagnosed. Often the only clue to their presence is an early vein on angiography. Repeat angiography may be necessary. We feel that most of the so called "angiographically occult" malformations are either micro AVMs or cavernomas.

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ASSOCIATION OF CEREBRAL SO-CALLED VENOUS ANGIOMAS WITH CRYPTIC VESSEL MALFORMATIONS G.Huber, M.Hermes, H.Henkes, U.Piepgras Department of Neuroradlology, Saarland-University, Homburg-Saar, FRG

~I-MORPHOLOGYAND CLASSIFICATIONOF CE~BRAL CAVERNOI~S

To evaluate the clinical relevance of the so-called venous onglomas we correlated in a group of 31 patients the neuroradiologleal findings with the clinical symptoms. All patients had a CT and/or MRI, a cerebral anglography and a complete neurological examination. In 15 of 31 patients the so-called venous angiomas were associated with a cavernoma or other cryptic vessel matformation. In 16 of 31 patients there was no such regional association. 6 of our 15 patients associated with cavernomas and 3 of 16 with "pure" venous angiomas had clinical symptoms. In addition we found 2 arterial aneurysmas, 2 skin anglomas and 1 arteriovenous dural fistula. Conclusion: Venous angiomas are often associated with regional cavernomas or other cryptic vessel malformations. Extracerebral vascular malformations are not rare. Clinical symptomas are more often in cases with cryptic vessel malformations then in uncombined "pure" cases.

S.~fer ,A.Val~i%w.wichmann De~z~entof ~e~o~diolo~,U~versity Snspi~lZurich,Z=ich NRPOSE A pros~tiveandretrospeGtive ~RI-studybefore~d aftertheinjectionof GD-D~Awas ~erteen to defins N~ise diNnstic ~I-~iteria of caverned.In additionthe ass~iation of Csvarn01aanddevel0~entalvenousan011a/y(!at/&)aSwellas the~ina9 patternof the cavern0mitself~s evaluated.

~Rl-~hol~ of theo~er~0~~s aaly~ in 55 histolNiallyverifi~averts &~ ~co~/y stuntedto S non-o~atedbut ra~ol0gisllysus~ectNoaver~ol#{all t~J~dl~r107 patients).GD-~A as b01nsinjectioni.v.wasuse in 32 cases(16hist010~ic~lly verified ~d 16 ssp~te csv~ome)withs d~agnof 20-40ml.~ultiplansrSE-s~quenneswere~erfor~ed on a Phili~s1,ST~R-~itwithTIW ~ndT2Wse@~nees. R~SN~ Them0rph010gic~~ffareneiasof thecavernomasledto a classifi0ati0, into5 subtypes:the basiccavern0~stype(typeI),thecavarnomawithintralesi0nal hel0rrhagnof differentextent (typeflu/h),the~varn0~awithextralasienal h~erthagn(typeIll),thecalcifie~cavernola { t ~ IV) and t ~ c~tic caverm~ ( t ~ V}.~ista~ N~ w~ree~rve~ in 3 s~ga- ar~ in 7 hfratonforialcavernousen ~IW/T2Wi=gs.(5single~ 5 ~ultigsN~).ln 2 easesa dk~t drainageof thecavemenintotheassociatedDVAwasvisible.DireXly drainingveins(on TIW/T2Wimages)w~e noticedin 6 s~a- ~d l infrat~t0rialcavernsss(drainageintothe deepor su~rficialven0nssysts),As0-callNraNatiNe~entent in thevicinityof the cave~0mws visible@ ~IWilsg~sgt~r GO inj~i0nin 6 infra-aN 6 s@rat~torial cavernomas.These c ~ ~re das~t~ as ~ e x ouverr~as. CONCLUSION ~ypI end liecavernonasarereli@lydiagnosedon ~ dueto theirt~ical~orph010gical feat~rs.The0thorty~s,how~vsr,o~c~sio~ally are~o~ensilydls~ish@le frolother 'as~l~ ~fosatios,hen~Tha~cn~la~ ~ calcifi~i~aoer~al l~ions. Theco~lexcsvern0mamaybe c0nsid~eds repres~tativeof a newentityof a venousvascular nalfor~/enthatis notconfinedto theca~enn0maitselfbutpr~entsalsowith~llf0rl~ ~ vesselsin thevicinityof the ision.Wesup~e the thismlfo~ationresulthfroma faslW ~y010~ic duelist of v~0ass ~ n s i a c ~ n brainareaeerensthe as~iat~l DVAprovidesthe~nss~ mr~l ~ ~mgn.

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STURGE-WEBER DISEASE - A VENOUS DISORDER? U.Piepgras, G.Huber, H.Henkes Department of Neurorodiology, Saarland-Unlversify, Homburg-Saar, FRG

PEDIATRIC STURGE-WEBER DISEASE - DETECTION OF LEPTOMENINGEJkL ANGIOMATOSIS BY Gd-DTPA ENHANCED MRI H. H e n k e s *°, G. lluber*, R. B i t t n e r °, J. S p u r n e r ~, N. H e y e +, U. P i e p g r a s * Institut fllr Neuroradiologie*,Homburg/Saar; Radiologische Klinik+,UKRV/SC,Universit~tskinderklinik ~, UKRV/SC sowie Institut fl%r N~aropathologie, Klinikum Steglitz der Freien Universit~t Berlin

A retrospective study evaluating the role of an abnormal venous drainage in Sturge-Weber disease. The study is based on a total of 23 patients. We analyzed critically the =ngiographie findings in 10 of our own patients and 4 referols (ages between 8 months and 43 years) and looked at relevant ongiograms published in the literature. Partial and complete absence of evidence of the deep veins was a constant feature. Besides this the superficial veins showed an inconstant variety of abnormalities which probably simply results from a following collateral drainage. We assume that these venous changes are present at birth and we have proven angiographically that they show no change with the passing of years. As our CT- and/or MR-studles in 17 patients show the mental disability does not correlate with the extent of the leptomenlngeal angiomotosis nor with the localized cerebral atrophy, the most known neuropathotogical hallmarks of the disease. The nonfunction of the deep venous pathways is in our opinion an important i f not the main pathogenetic factor in the development of the usually severe general mental dysfunction in patients with Sturge-Weber disease.

In children with congenital facial port wine nev~s the detection of leptomeningeal a11gic~matosis is proof of the diag~losis "Sturge-Weber disease". Beside clinical s!nnptc~ns (seizures, hEmliparesis, hemianopsia, m e n t a l retardation), key findings are (a) gyriform c a l c i f i c a t i o n s seen b y c o n v e n t i o n a l radiographs, (b) diffuse cortical calciu~n deposits d e m o n s t r a t e d b y CT and (c) a dysplastic deep cerebral venous system proved by angiography.Patlents and methods: Six c h i l d r e n with clinical siglls a~id slnnptc~ns of S~TD (age range 6-24 m o n t h s ) u n d e r w e n t C~ and MRI examinations, (both u n e n h a n c e d and contrast enhanced) in a prospective study protocol. Results: In all six children, a l o c a l i s e d of d i f f u s e b r a i n a t r o p h y was present. CT de-monstrated oortical calcifications in 3 a n d l e p t o m e n i n g e a l a n g i o m a t o s i s in 1 infant. MRI showed abnormalities of the m e n i n g e s , especially i n t e n s i v e c o n t r a s t en/%ancement, in all p a t i e n t s . Together with dilated penetrating veins and angiomatous enlargement of tile choroid plex~is this was a highly characteristic finding, confirming the diagllosis of Stu-rge-Weber disease. In conclusion, the d e m o n s t r a t i o n of leptomeningeal/~lnd c h o r o i d p l e x u s angiomatosis and venous abnormalities by contrast erdlanced M R imaging allows the direct proof of Stur~eW e b e r d i s e a s e in e a r l y childhood, e v e n b e f o r e o t h e r moz~ghological c o r r e l a t e s such as severe a t r o p h y a n d cortical calcifications can be demonstrated.

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INTRACRANIAL DURAL ARTERIOVENOUS SHUNTS CAUSING VENOUS CONGESTIVE ENCEPHALOPATHY. K.G. terBrugge, L.N. deTilly, W.J. Montanera, R.A. Willinsky, M.C. Wallace. The Toronto Kospital - The Western Division

MR Imaging in cerebral venous thrombosis : 24 cases with angiographic correlation. D. Dormont, S. Evrard, J. Chiras~ C. Marsault. Neuroradiology Dept., Piti~-Salp~tri~re, PARIS.

The clinical and radiologic data of 49 patients with cranial dural arteriovenons shunts were reviewed. These presented to the Toronto Western Hospital between 1984 and 1990. Thirty-two were dural arteriovenous malformations (AVMs) and 17 were carotid-cavernous fistulae. The focus of this report is to correlate associated cortical venous drainage (CVD) and/or venous occlusive disease to symptomatology. The clinical presentation of 12 patients with cortical venous drainage included 3 patients with subarachnoid hemorrhage, i with cerebellar infarction, 2 with parenchymal hematomas, i with hydrocephalus, and 2 patients with rapid onset dementia. Direct venous pressure monitoring of the transverse sinus showed a significant pressure gradient in I of the 2 patients with encephalopathy associated with a dural AVM with cortical venous drainage and venous occlusive disease. The MRI revealed signal abnormalities within the brain parenchyma in this patient. Following embolization of the dural AVM in this patient all clinical symptoms disappeared. This would indicate that dural AVM with cortical venous drainage in the presence of venous stenosis or occlusion can cause venous congestive encephalopathy which is reversible once recognized and treated accordingly.

Magnetic Resonance Imaging is used increasingly for the evaluation of suspected cerebral venous thrombosis (CVT). The purpose of our study was: i) evaluate the MR sensitivity to CVT on our series of 24 angiographically proven CVT, ii) study the evolution of CVT with MR 9 iii) compare the MR and CT appearances of venous infarctions. Patients were 9 males and 15 females~ ranging in age from 21 to 77 years. MR has been performed at 0~ST or I,ST. All patients were studied with sagittal Tlw spin echo (SE) and coronal T2w SE sequences. In addition, flow sensitive coronal Tlw gradient echo images were obtained at 195T. Thirteen patients had follow up MR studies. In 6 cases control angiograms were also available. MR scans were correlated with an~iograms and CT scans. Our main results are : i) thrombosis of dural sinuses was visible on MR in 22/24 cases, estimation of MR sensitivity to CVT is thus 9 1 % , ii) evolution of CVT can be followed with MR, in our patients partial or complete recanalization under treatment was observed in 12/13 cases, iii) MR and CT sensitivity to venous infarctions is analogous. MR can thus be considered actually as the first non-invasive imaging modality to study CVT but its sensitivity is not sufficient to make the diagnosis in all cases. In the future~ the use of MR angiography will probably help to make the diagnosis in these cases.

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CEREBRAL SINUS THROMBOSIS A N D M R I J. R e u l ~, Ch. I s e n s e e **, A. T h r o n *, H.B. Gehl * • Neuroradiologie, Radiologische Klinik, • * Neurologische Klinik, Klinikum RWTH Aachen

VENOUS SINUS THROMBOSIS: MAGNETIC RESONANCE ANGIOGRAPHY (MRA) IN DIAGNOSIS AND FOLLOW UP

N i n e p a t i e n t s w i t h p r o v e n c e r e b r a l sinus t h r o m b o s i s w e r e e x a m i n e d in M R I u s i n g s p i n echo techniques (total of 25 e x a m i n a t i o n s ) . T i m e d e p e n d e n d s i g n a l i n t e n s i t y p a t t e r n s of thrombsed sinus allowed a differential staging a c c o r d i n g to e a r l y s t a g e s of i n t r a c e r e b r a l haematomas: I. Early stage (day 1-4) strong hypointensity on T2wI, hypo- or isointensity on pwI. II° I n t e r m e d i a t e stage: i n c r e a s e of s i g n a l (metHb) to complete hyperintensity. III. S t a g e of t h r o m b u s o r g a n i s a t i o n and/or recanalisation (3rd to 4th week): Decrease of size and signal of the thrombus. IV. Stage of d e f i n i t e complete or i n c o m p l e t e organisation or recanalisation of thrombus. MR-angiography was performed on 7 patients at least once. If the c h a r a c t e r i s t i c s i g n a l p a t t e r n s of cerebral sinus t h r o m b o s i s at d i f f e r e n t times of the disease evolution are kept in mind, the d i a g n o s e s c a n e a s i l y be m a d e or e x c l u d e d b y MRI-examinations. Variation of the examination parameters and combination of S E - s e q u e n c e s with flow-sensitive sequences allowed acurate differentiation of f l o w - a r t i f a c t s a n d n o r m variants. Uncooperative or clinically instable patients should be examined by angiography.

B. Ostertun, L. Solymosi, W.Kaiser, M. Reiser Departments of Radiology/Neuroradiology, University of Bonn, FRG P u r p o s e : Venous s i n u s thrombosis u p to now is verified by CT, Magnetic Resonance Imaging (MRI) a n d x-ray angiography. The potential role of Magnetic Resonance Angiography (MRA) as a non-invasive method in primary diagnosis a n d follow-up should be evaluated in this study. Materi~l mad Method: 20 examinations employing 2D timeof-flight MRA in patients with suspicious clinical symptoms, CTor MRI- findings s u c h as headache, seizures, atypical haemorrhage, direct depiction of thrombi or known dural-based tum o u r s were performed. Diagnosis w a s verified by angiography a n d CT in most primary cases; sensitivity a n d specificity of all available imaging modalities were compared. R e s u l t s : MRA with a 2D Inflow technique visualizes the whole venous s i n u s s y s t e m with an image quality comparable to conventional angiography, w h e n both transversal a n d coronal s c a n s are performed. Thromboses a n d stenoses found in conventional angiography, CT or Mill were verified by MRA in all cases. Improvement as well as progression of t h r o m b o s i s u n d e r full-heparinization, which w a s not necessarily accompanied by a parallel development of clinical symptomatology, were observed with MRA. In 2 pregnant women with negative MRA no xray imaging w a s performed: both proved to suffer from eclampsla. Conclusion: MRA is a reliable tool for diagnosis a n d followu p of venous s i n u s thromboses. Simultaneous MRI realizes accompanylng congestive haemorrhage a n d differential-diagnostic pathology. Thus, where avaflabIe, MR can replace repeated CT and x-ray angiographv in this indication.

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Scientific Session:

Cerebrovascular Disease

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2

Moderators: A. Thron, Aachen, Germany and L. Picard, Nancy, France

11.00 a m - 12.30 pm

Scientific Papers 123-133

t2.30 pm-01.30 pm

Lunch

11.00 am-12.30 pm Scientific Papers 123-133 123 Volume blood flow measurement in individual arteries using video recordings of digital subtraction angiograms J.N. Brunt, G.H. du Boulay, A. Wallis, D.A. Wicks, Manchester/London, United Kingdom 124 Measurement of the cerebral blood flow (CBF) during balloon Matas test using positron emission tomography (PET) A. Inugami, E Shishido, T. Ogawa, H. Fujita, E. Shimosegawa, H. Ito, K. Uemura, Akita, Japan

129 MRI-angiography in the evaluation of intracranial aneurysms C. Louail, M. Raynaud, D. Gense de Beaufort, J. E Gr6selle, J.M. Caill6, Bordeaux, France 130 Evaluation of intracranial aneurysms using threedimensional time of flight MR angiography A. Rovira, EJ. Romero, B. Ibarra, J. Capellades, J. Gili, Barcelona, Spain

A.

Vivas,

131 3-D-MR-angiography for acute subarachnoid hemorrhage 125 Venous and arterial cerebral flow measurements: Comparison of MRI and TCD D. Ott, J. Hennig, R. Schillinger, M. Hengherr, A. Hetzel, Ttlbingen/Freiburg, Germany 126 Blood flow quantification in the carotid arteries with magnetic resonance S.E. Maier, K. Liu, P. Boesiger, Zurich, Switzerland 127 2D-FT low-field MR angiography (MRA) of epiaortic extracranial vessels: Preliminary results M. Gallucci, P. Pavone, A. Bozzao, C. Catalano, G. Albertini Petroni, E. di Cesare, R. Passariello, L'Aquila, Italy 128 Magnetic resonance angiography (MRA) of the brain and neck: Evaluation of state of the art methods on 200 patients E.D. Gotsis, E. Kapsalaki, L. Stylopoulos, N. Bontozoglou, Z. Kapsalakis, Athens, Greece

E. Volle, R. Gustorf-Aeckerle, R. Kraft, K.-H. Holbach, 13.Atay, M. Spanopoulos, R. Hausmann, Stuttgart/Erlangen, Germany 132 CT study of carotid bifurcations: Possibilities and diagnostic protocol M. Leonardi, B. Zanotti, G. Fabris, A. Lavaroni, E. Biasizzo, S. D'Agostini, Udine, Italy 133 Intracranial EEG recordings from intra-arteriai guide wires P. Stoeter, L. Dieterle, A. Meyer, N. Prey, Ravensburg, Germany

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VOLUME BLOOD FLOW MEASUREMENT IN INDIVIDUAL ARTERIES USING VIDEO RECORDINGS OF DIGITAL SUBTRACTION ANGIOGRAMS J N Brunt*, G H du B0ulay2, A V~allis2 ,D A Wicks2 tMedical Biophysics Dept, Manchester University, M13 9PT UK 2Institute of Neurology, Queen Square, London WCIN 3BG UK

MEASUREMENT OF THE CEREBRAL BLOOD FLOW (CBF) DURING BALLOON MATAS TEST USING POSITRON EMISSION TOMOGRAPHY (PET) A.Inugami, F.Shishido,T.Ogawa,H.Fujita, E.Shimosegawa, H.Ito, K.Uemura. Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, JAPAN

We investigated computer analysis of DSA video-recordings for volume blood flow measurement in carotid and cerebral arteries. For validation, we recorded fluid flows through 3D--calibrated tortuous tubes of 2 to 7 ram diameter. A calibrated e.m. flowmeter measured the flows during contrast medium (CM) injections. Video sequences of 2.6s duration are played back, and images are sampled along a vessel of interest. Values from perpendicular density profiles (corresponding to CM mass per unit vessel length) form a vector'. Each vector, corresponding to a single video frame, is drawn into a 'parametric image" representing CM mass or concentration as a function of distance along the vessel and of time. Volume flow is obtained by incorporating calibre measurements and deriving instantaneous, local flow velocity from the inclination of the isoconeentration contour at any point in the image using various image processing algorithms. The validation experiments produced angiographic flow measurements agreeing with e.m. flows to within 5 % in the larger tubes. We have analysed carotid DSA recordings from 6 patients. Making the video recordings takes approximately four minutes during a clinical anglogram. We conclude that accurate flow measurements can be made from carotid DSA video recordings. We expect the technique to have sufficient sensitivity to measure flow in the anterior and middle cerebral arteries, though precision may be less good.

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VENOUS AND ARTERIAL CEREBRAL COMPARISON O F MRI A N D T C D

D.Ott*(**),

Aim of this study is to emphasize the functional evaluation of the balloon Matas test with repeatedly measured, quantitative CBF before treatment of intracranial major arteries. The balloon Matas test was carried out at the internal carotid artery on two cases with giant aneurysms. We measured regional CBF (rCBF) using H 2 1 5 0 and PET at rest, 5 and 30 rain after the commencement of the balloon Matas, and 10 and 25 min after the end of it. We monitored EEG. During the balloon Matas the patients showed normal EEG without any symptom. Mean rCBFs at the temporo-parietal watershed area of the affected side were 40.7, 28.1, 19.6 and 30.3 ml/ 100ml/min at rest, 5 and 30 min of the Matas, and 25 min after end of the Matas, respectively, and rCBF at the same region of the contralateral side were 53.9, 40.5, 42.5 and 49.8 ml/100ml/min respectively. Note at 30min of Matas test, rCBF decreased to 19.6 ml/ 100ml/min (i.e. critical threshold level) at the watershed area. But conventional hand compression Matas test did not show any abnormality. In conclusion, we need functional evaluation of the balloon Matas test with quantitative measurement of rCBF before the treatments of the major arteries.

J.Hennig**,

FLOW

MEASUREMENTS:

R.Schillinger**,

M.Hengherr** and A.Hetzel***

* Dpt. of Neurorad., TQbingen,** Dpt of Diag. Radiology,***Dpt of Neurology, Univ. of Freiburg The Fast Fourier Flow (FFE) method allows quantitative MRI flow studies on the basis of timedependant flow profiles over the chosen vessel diameter. In 20 volunteers and I0 patients (AVM, Thrombosis, sinus compression due to mass, NPH) the sinus flow was measured. 15 volunteers and 9 pts with arterioslcerotic disease were examined by MRI (FFE) and by transnuchal TCD using a 2MHz probe at the midbasilar artery, between junction and midbasilar and the intracranial vertebral artery. The common carotid artery was measured in 13 normals and in 6 arteriosclerotic patients. The MR flow measurements were performed at a 2T whole body system (Bruker) using the Fast Fourier Flow (FFE) method: TR = 38ms,TE=23 ms, 13-20 frames/cardiac cycle, acquisition time 50-70 sec. Flow sensitivity : i.I -1.7 cm / sec / pixel. Normal flow volumes in the superior sinus did not show much interindividual variations ( 235 ml/min +/- 38), the average flow in the straight sinus was 64ml/min +/-16. 4/5 patietns with AVMs had significantly increased sinus flow (> 2s than reference) with a maximal measured flow volume of 817 ml/min. The patients with total or partial thrombosis and tumoral compression all had significantly reduced sinus flow (less than 2s below reference group). The correlation of MR and TCD was done for the peak systolic, peak diastolic and time-mean peak velocity of the envelope curve. Due to poor insonation conditions or non detectable signal in MRI we included only 17 patients in the correlation study. The correlation of these data was good, even uncorrected for the TCD insonation angle. The advantages Of FFE consist in exact localization accessibility of all larger v e s s e l s and spatial resolution, whereas TCD provides a better temporal resolution and is less dependant on laminar flow conditions than FFE.

Blood Flow Quantification in t h e Carotid Arteries with Magnetic Resonance S.E. MAmR, K. LIu, P. BOESmER Institute of Biomedical Engineering and Medical Informatics, University and ETH Zurich, Switzerland I n t r o d u c t i o n : Blood flow can be visualized by Magnetic Resonance (MR) phase images. Due to the linear relationship between the flow velocity and the phase of the MR signal 2-dimensional blood flow velocity maps can be acquired (MR phase contrast method). Using electrocardiogram triggering observation of blood flow is possible over the entire heartcycle with a time resolution down to 25 m s . Methods: A specially designed MR sequence was applied on a Philips GYROSCAN $15 1.5 Tesla system for velocity mapping of the carotid arteries in volunteers. An electrocardiogram synchronized series of velocity maps was acquired at a field of view of 200 m m with a lateral resolution of 0.8 m m . It allowed for a simultaneous visualization of blood flow in the larger neck vessels including the vertebral arteries. The total instantaneous flow rate was computed by adding up the pixel values over the entire vessel area. Results a n d Conclusion: Flow rate quantification showed in accordance with US Doppler measurements flow profiles with strong pulsatility of the external and reduced putsatility of the internal carotid artery. The 2-dimensional velocity maps clearly depicted the region of the carotid bulb with regions of reverse blood flow proximal to the vessel wall persisting over the entire heart cycle. Phase based 2-dimensional MR velocity mapping can become a new accurate method to diagnose lesions of the neck vessels. The method provides flow rates of all large neck vessels within one scan and is not limited by access windows as US Doppler. ~hrthermore the 2-dimensional velocity maps may reveal detailed information about, hemodynamic determinants of atherosclerosis.

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2D-FT LOW-FIELD MR ANGIOGRAPHY (MRA) OF EPIAORTIC EXTRACRANIAL VESSELS : PRELIMINARY RESULTS M. G a l l u c c i , P. P a v o n e , A.Bozzao, C. C a t a l a n o , G. A l b e r t i n i P e t r o n i , E. D i C e s a r e , R. P a s s a r i e l l o Dept. of R a d i o l o g y , University of L ' A q u i l a , Italy

M a g n e t i c R e s o n a n c e A n g i o g r a p h y (MRA) of the B r a i n a n d Neck: E v a l u a t i o n o f S t a t e of the A r t M e t h o d s o n 200 p a t i e n t s

Two-dimensional Fourier transform (2D-FT) t i m e - o f - f l i g h t M R A w a s p e r f o r m e d i n I0 h e a l t h y volunteers and in 20 p a t i e n t s with known carotid pathologies. MRA was carried out by m e a n s of a 0.2 T e s l a p e r m a n e n t magnet. There w e r e 12 c a s e s of internal and or external carotid artery stenosis, 6 internal carotid a r t e r y (ICA) o c c l u s i o n s a n d 2 I C A d i s s e c t i o n s . In a l l c a s e s comparative angiography was a v a i l a b l e ; in 15 color Doppler was also performed. A standard neck coil was employed. A s e r i e s of 25 to 64 a x i a l and/or saqittal images were obtained with oblique and/or s u p e r i o r s a t u r a t i o n to suppress v e n o u s flow. Standard acquisition parameters were: 26-cm f i e l d of view, 2-mm thickness with l-mm o v e r l a p , 1 or 2 e x i t a t i o n s , 2 2 4 x 2 5 6 m a t r i x a n d 90 ° f l i p angle. TR ranged b e t w e e n 30 to 120 m s e c ; T E w a s 10 m s e c . In all n o r m a l v o l u n t e e r s l o w - f i e l d M R a n g i o g r a p h y a l l o w e d to d e p i c t the a n a t o m y of c a r o t i d biforcation and that of e x t r a c r a n i a l ICA. A l l c a s e s of I C A o c c l u s i o n were correctly identified by low-field MR a n g i o g r a p h y ; 4 o u t of 12 o a s e s of stenosis w e r e o v e r - e x t i m a t e d as w e l l as 1 case of dissection. I n a l l the c a s e s w i t h s i g n i f i c a n t h e m o d i n a m i c s t e n o s i s (over 50%) M R a n g i o g r a p h y was judge equally informative. In our e x p e r i e n c e l o w - f i e l d M R a n g i o g r a p h y o f f e r s the same possibilities and presents the same l i m i t a t i o n s of h i g h f i e l d one.

E D G o t s i s , E. K a p s a l a k i , L. S t y l o p o u l o s , N. B o n t o z o g l o u , a n d Z. K a p s a l a k i s Institute ENCEPHALOS, Halandri, Athens, Greece P u r p o s e : To e v a l u a t e s t a t e o f the art M R A t e c h n i q u e s (2D a n d 3D T O F a n d 3D P h a s e C o n t r a s t ) in brain and neck vessel abnormalities. M a t e r i a l s a n d M e t h o d s : 200 p a t i e n t s (i-85 y e a r s old) w i t h k n o w n or s u s p e c t e d v a s c u l a r a b n o r m a l i t i e s o f the b r a i n a n d n e c k v e s s e l s w e r e e x a m i n e d o n a 1.5 t system. In m o s t cases, at l e a s t o n e set o f s p i n e c h o a x i a l s l i c e s w e r e a c q u i r e d . In all c a s e s b o t h T O F a n d p h a s e c o n t r a s t t e c h n i q u e s w e r e used. R e s u l t s : 20 a n e u r y s m s r a n g i n g f r o m 2 to 20 m m in size, 35 AVM's, and 50 s t e n o s e s (two t h o u g h t to be M o y a - M o y a disease) w e r e p r o p e r l y i d e n t i f i e d and characterized. All aneurysms were surgically c o n f i r m e d . The r e m a i n i n g 95 c a s e s w e r e c o n s i d e r e d normal. C o n c l u s i o n s : P h a s e c o n t r a s t t e c h n i q u e s w e r e cons i d e r e d i n d i s p e n s a b l e in r e m o v i n g h e m a t o m a s and t h r o m b u s e s f r o m the p i c t u r e , t h u s a l l o w i n g p r o p e r e v a l u a t i o n of the lesions, p a r t i c u l a r l y A V M ~ s and a n e u r y s m s w i t h h e m a t o m a p r e s e n t . 2D TOF t e c h n i q u e s w e r e h e l p f u l in d e p i c t i n g the v e n o u s d r a i n a ge of AVM's. M R A can d e f i n i t e l y be u s e d as a s c r e e n i n g m e t h o d for s u s p e c t e d b r a i n or n e c k v e s sel a b n o r m a l i t i e s , p r o v i d e d t h a t t h e p r o p e r c o m b i n a t i o n o f t e c h n i q u e s is used.

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129 MRI-ANGIOGRAPHY IN THE EVALUATION OF INTRACRANIAL ANEURYSMS C. Louall, M. Raynaud, D. Gense deBeaufort, J.F. Gr~selle, J.M. Calll6 Service de Neuroradiologie. CHR. 33076 BORDEAUXC&lex(France)

The authors evaluated the contribution and limitations of angiography by magnetic resonance in the diagnosis, the pretreatment evaluation and the surveillanceof intracran~alaneurysms. Ten intracranial aneurysms were explored with conventional angiography and MRI-angiography. The examinations were performed with o Magnetom SP Siemens 1.5 Tesla, using 3D FISP acquisition with short RT, as well as conventional TI- and T2-weighted spin-echo sequences. The analysis of the results comprised the spin-echoes, the 3D sections and ~ reconstructions by the MIP method. All the aneurysms were visualized with this technique but a good analysis of the neck was not possible because of insufficient spatial definition. In two case of partially thrombosed aneurysms, the MRI-angiography provided a better definition of the relations with adjacent vessels than did conventional angiography, thus giving important informations for the evaluation before surgery. The place of MRI-angiography in relation to conventional angiography has yet to be established and will need further assessment. MRIangiography appears to be interesting in the evaluation of unoperated intracraniat aneurysms because it is not traumatic. It also appears particularly interesting in the preoperatory evaluation of partially thrombosed aneurysms, defining the relations of the aneurysm with adjacent vessels.

EVALUATION OF INTRACRANIAL ANEURYSMB USING THREE-DIMENSI0NAL TIME OF FLIGHT MR ANGIOGRAPHY. A. Rovirs, FJ. Romero, B. Ibarra, A. Vivas, J. Capellsdes, J. Gili Unidsd de Resonancia Magnetica y Servioio de Neuroradiologia. Ciudsd Sanitaria de la Vall d'Hebr6n. Barcelona (Spain). The value of three-dimensional time-of-flight MR engiography was prospectively evaluated in 20 patients with intrscranial aneurysms, using a 1.5T superconductive magnet. In all the patients the 3D reconstructions were evaluated in conjunction with the individual partitions and conventional cranial MR. A cranial CT was performed in all the oases, mainly because an acute subarschnoid haemorrhage. The distribution of the blood in the subarachnoid space and sometimes abnormal enhancement lesions around the basal cisterns, determined in some cases the slab location and thickness of the 3D-MR angiography. With this approach almost any aneurysm detected whith conventional angiography was missed, but in several cases the exact location and size of the aneurysm were difficult or even impossible to asees with MR. MRA may have a role in screening symptomatic patients, but at present it is not adequate as a replacement for conventinal angiography in preoperative evaluation.

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3 - D - M R - A N G I O G R A P H Y FOR ACUTE S U B A R A C H N O I D HEMORRHAGE

CT STUDY OF CAROTID BIFURCATIONS Possibilities and diagnostic protocol M. Leonardi, B. Zanotti, G. Fabris, A. Lavaroni E. Biasizzo, S. D'Agostini Servizio di Neuroradiologia, Ospedale Civile; Udine, Italy

E Volle z, R G u s t o r f - A e c k e r l e *, R Kraft *, K-H H o l b a c h **, B A t a y **, M Spanopoulos **, R H a u s m a n n ***: D e p a r t m e n t of Neuroradiology and ** D e p a r t m e n t of Neurosurgery, K a t h a r i n e n h o s p i t a l Stuttgart and x** Siemens M e d i c a l Systems Erlangen. A m o n g 73 p a t i e n t s with acute s u b a r a c h n o i d h e m o r r h a g e e x a m i n e d by CT there were 33 patients with stage I-If a c c o r d i n g to Hunt and Hess, 26 of these p a t i e n t s were examined by 3-D - M R - a n g i o g r a p h y and results c o m p a r e d with cerebral angiography. In 18 p a t i e n t s a c o m p a r i s o n with surgical findings could be performed. The aneurysms could be d i v i d e d into 5 regional groups and into 4 types a c c o r d i n g to their size. In this g r o u p 18 patients had 20 aneurysms, 19 of these were c o n f i r m e d at surgery. 3-D-MRa n g i o g r a p h y d e m o n s t r a t e d i0 of these 20 aneurysms ( = 50% ). In 8 p a t i e n t s without a n g i o g r a p h J c proof 3 - D - M R - a n g i o g r a p h y also failed. Aneurysms below 0.5 cm d i a m e t e r can not be d e m o n s t r a t e d because of limited r e s o l u t i o n due to insufficient pixels per flow. In a d d i t i o n high signal T1 structures (especially d e g r a d e d blood ) can interfere diagnostically. The main advantages of 3 - D - M R - a n g i o g r a p h y are the p o s s i b i l i t y to select freely anyone of the 3 axes in space (MIP), it's non invasive character, the fact that no contrast i n j e c t i o n is r e q u i r e d and f i n a l l y the p o s s i b i l i t y to recognize a p a r t i a l l y thrombosed aneurysm.

133 I N T R A C R A N I A L E E G R E C O R D I N G S FROM INTRA-ARTERIAL GUIDE WIRES P. Stoeter, L. Dieterle, A. Meyer, N. P r e y Dep. of N e u r o r a d i o l o g y a n d Dep. of Neurology, E l i s a b e t h e n - K r a n k e n h a u s , Ravensburg, Germany. I n t r a c r a n i a l EEG recordings were carried out b y m e a n s of i n s u l a t e d Seeker-lO-guide wires ( R e h a f o r u m M e d i c a l ) . T h e s e guide w i r e s were c o v e r e d w i t h a continuous teflon c o a t i n g l e a v i n g o n l y the distal (20 mm) and p r o x i m a l p a r t s unprotected. In the course of a n e x t e r n a l carotid angiography with i n t e n d e d embolisation, the guide w i r e s w e r e i n t r o d u c e d intracranially into t h e f r o n t a l or p a r i e t a l branch of the m i d d l e m e n i n g e a l artery. Because of the l o w c o n d u c t i v e resistance of the wires of a b o u t 40 ohm, high-voltage p o t e n t i a l s c o u l d b e r e c o r d e d from the s u r f a c e of t h e t e m p o r a l lobe which w e r e 2-4 t i m e s s t r o n g e r t h a n the simultaneously r e g i s t r a t e d e x t r a c r a n i a l EEG. We intend to a p p l y t h i s t e c h n i q u e to other areas the h e m i s p h e r e s a n d b r a i n stem via l e p t o m e n i n g e a l and b a s a l cerebral arteries.

The study of carotid bifurcations needs the evaluation of blood flow and the analysis of the structure of the arterial walls. Examinations particularly involved in the dynamic studies are US-Doppler, angiography, MR-angiography. The study of the arterial walls offered by these examinations is limited to the met "cast" of the lumen, without a true evaluation of the walls parenchima. Till now, the only examination widely used for these purposes was the US-tomography, an examination difficult to he reproduced, limited by the skillness of the physician and without a standardised technique. CT study of the carotid bifurcations, made possible by the new fast and high resolution CT systems, after blus injection of non-jonic contrast medium, offers the analysis of the morphology of the arterial walls, with the identification of the structure of the plaques, and the evaluation of the lumen opacified by contrast medium in blood. Quality of information looks so wide and complete to suggest the proposal of considering this kind of study the most informative, without beeing particularly invasive, of the possible examinations of such an important anatomical region. The authors suggest a new protocol for the study of carotid bifurcations, considering the CT study as the first exam after clinical and Doppler sonography examinations.

Ist CONGRESS OF THE WORLD FEDERATION OF INTERVENTIONAL AND THERAPEUTIC NEURORADIOLOGY October 11-13, 1991 Held under the patronage of the

European Society of Neuroradiology Congress Presidents: J. Moret and A. Valavanis Scientific Program Committee H.T. Apsimon, Perth J. Bonneville, Besang.on G. Debrun, Baltimore A.J. Fox, London, Ontario K. Goto, Fukuoka V.V. Halbach, San Francisco

B. Kendall, London J. Moret, Paris (Chairman) R. Piske, Sao Paulo E Svendsen, GOteborg H. terBrugge, Toronto H. Zeumer, Hamburg

S 133

World Federation of Interventional and Therapeutic Neuroradiology The World Federation of Interventional and Therapeutic Neuroradiology (WFITN) was founded on January 16, 1990, in Val d'Is6re, France. The World Federation of Interventional and Therapeutic Neuroradiology links the committees and subcommittees on Interventional Neuroradiology of the continental societies of Neuroradiology. The following objectives of the federation were unanimously adopted by the Founding Members: 1. To provide world-wide representation for interventional and therapeutic neuroradiology 2. To develop standards for training and practice in interventional and therapeutic neuroradiology 3. To promote and encourage the formation of regional and national groups under the umbrella of existing regional or national societies. The World Federation of Interventional and Therapeutic Neuroradiology is open to all individuals with a recognized reputation in the field of interventional and therapeutic neuroradiology. Senior members must devote a significant portion of their professional time and practice to neuroendovascular therapy, be recognized in their geographic region for this practice and be committed to teaching, clinical investigation, and/or scientific research in the field. Junior members will have begun similar commitments or will be completing training soon. Associate membership is open for those who have a serious interest or involvement in some aspects of the practice of interventional neuroradiology but who do not otherwise qualify for senior membership. Interested neuroradiologists, other physicians and scientists are welcomed as members of the Federation in one of the three membership categories.

Executive Committee 1990-1992 President Alex Berenstein

Secretary Pierre Lasjaunias

Vice-President Luc Picard

Treasurer Jacques Moret

Committees Membership Committee

Liason Committee

A. Fox (Chairman) G. Campos G. Debrun K. Goto B. Kendall J.J. Merland

L. Picard (Chairman) T. Apsimon P. Lylyk C. Strother W. Taki

Finance Committee

Publication Committee

J. Moret (Chairman) S. Bien G. Hieshima M. Negoro G. Scialfa A. Valavanis

A. Molyneux (Chairman) V. Halbach R. Piske A. Takahashi K. terBrugge E Vinuela

General Members Andrew Molyneux Giuseppe Scotti Fernando Vifiuela

S 134

Special Focus Session (ESNR, WFITN)

tmoovascular lreatmem ot uereDral Aneurysms: facts, Controversies and Perspectives Chairmen: M.G. Ya~argil, Zurich, Switzerland and J. Moret, Paris, France 01.30 pm

Opening Remarks, A. Berenstein, New York, USA President of the WFITN

01.35 pm

Endovascular Treatment of Extradural Aneurysms G. Debrun, Baltimore, USA

01.55 pm

Endovascular Treatment of Berry Aneurysms by Endosaccular Balloon- Occlusion J. Moret, Paris, France

02.15 pm

Endovascular Electrothrombosis of Intracranial Aneurysms: Experimental Research and Initial Clinical Applications G. Guglielmi and F. Vifiuela, Los Angeles, USA/Rome, Italy

02.35 pm

Angioplasty for Cerebral Vasospasm J. Eskridge, Seattle, USA

02.55 pm

Discussion and Remarks

03.10 pm - 03.30 pm

Coffee Break

Endovascular Treatment of Extradural Aneurysms G.M. Debrun The Johns Hopkins Medical Institutions, Baltimore, Maryland, USA Most of the extradural aneurysms are on the ICA. A few are on the extradural portion of the vertebral arteries. We will essentially speak of the ICA extradural aneurysms. Most of these aneurysms are giant aneurysms with a broad neck on the cavernous portion of the ICA. The cavernous aneurysms are often now an incidental finding (MR angiography, MRI, CAT scan, angiogram). When patients develop symptoms, the cavernous syndrome is usually a VI nerve palsy associated with retroorbital pain. It is often difficult to localize with accuracy the limits of the neck. However it is crucial to know whether or not the neck is below the origin of the ophthalmic artery. When the neck straddles the OA the treatment is more difficult (the OA has to be occluded) and the upper portion of the aneurysm may be in contact with the SA space (higher risk of bleed).

Asymptomatic aneurysms do not need to be treated. The risks are greater than the natural history of the disease. Patients with permanent symptoms should be treated. We have the choice between occlusion of the sac with balloon or coils with preservation of the ICA and permanent occlusion of the ICA with balloons. As most of these giant aneurysms are compressing the oculomotor nerves and fifth nerve, have a very broad neck, permanent occlusion of the ICA is a good modality of treatment. The ICA must be trapped with balloons on both sides of the neck, or with occlusion immediately proximal to the neck if it is impossible or dangerous to detach a second balloon distal to the neck. However, the aneurysms straddling the OA must be treated with permanent occlusion of the OA (with balloon whenever feasible or with intracranial surgery if it is not possi-

S 135 ble). Permanent occlusion can be done only if the patient passes the balloon occlusion test. The time of occlusion differs from one institution to the other and is between 15 and 30 min. The test can be more accurate by associating EEG recording, cerebral blood flow (CBF) study or relative hypotension. After occlusion of the ICA, the patient must be monitored in the ICU with permanent recording of the blood pressure which has to be maintained slightly above base line. Any drop of blood pressure can result in a devastating ischemic complication in border line Circle of Willis patients.

It is debated whether embolic complications occur less often when the patient is heparinized after treatment or not. The results are usually excellent with a complication rate of 5%. When the aneurysm is equal to or smaller than 2 cms and has a relatively narrow neck, preservation of the ICA should be attempted with balloon or coils. Coils generate actually a lot of enthusiasm but it is too early to know the percentage of aneurysms which are anatomically cured with this technique.

Endovascular Treatment of Berry Aneurysms by Endosaccular Balloon Occlusion J. Moret l, A. Boulin l, M. Mawad 2, L. Castalngs 1 i Department of Interventional Neuroradiology Fondation Rothschild Hospital, Paris, France 2 Department of Neuroradiology Methodist Hospital, Baylor University, Houston, Texas, USA Although the surgical experience of treatment of aneurysms is tremendously large versus the endovascular one, it becomes possible to have a good idea of what the future will be as far as we have a better approach of the endovascular treatment possibilities and results. In order to avoid to compare "apple and potatoes", this study will take in account only what is commonly called "berry aneurysms", that is to say typical surgical aneurysms whose sizes are equal or inferior to 1.5 cm, and which extend intracranially and in almost all the cases totally in the subarachnoid space (see table of localizations). The specificity of our study is double: First it is indeed strictly comparable to the neurosurgical series regarding the material as it has been described above; second all the aneurysms have been treated by the same team, using the same endovascular technique and the same rules of follow-up (first control angiogram 4 to 6 months after the endosaccular occlusion, second control angiogram one year after the first one). All the aneurysms underwent an endosaccular occlusion using a latex balloon filled up with 100%0 of polymerizing substance (POLYMERAN from BALT company). Navigation, positioning and detachment of the balloon have been performed using a catheter specially designed for that use (Magic BD 2L from BALT company). Endosaccular occlusion is achieved according to three different methods: "Endosaccular clipping, endosaccular packing and endosaccular valving" (see schematic drawing). At the time of that paper 128 aneurysms in 124 patients have had an attempt of treatment. 22 cases were acute patients who bled within 48 hours before treatment; 45 cases were non acute patients (bleeding 10 days to some weeks before treatment); 61 patients had never hemorrhaged. Because of arteriosclerosis or impossibility of occluding the aneurysmal sac or impossibility of entering the aneurysmal neck, the endosaccular treatment failed in 36 cases (10 of those failures have been treated by parent vessel occlusion). In 1 case, although the balloon was perfectly occluding the aneurysm, we decided to quit because the anchorage of the balloon was suspected to be borderline and we did not want to take any risk in an asymptomatic patient specially because it was an easy localization for a neurosurgical treatment. Finally 101 of the 128 cases (79%) were successfully treated. Over these 101

treated cases, 91 had a selective occlusion of the aneurysmal sac, and 10 an occlusion of the aneurysm and the parent vessel. 4 patients have had 2 aneurysms treated by endosaccular occlusion. The long term follow-up shows 18 recurrences over the 91 aneurysms treated by selective occlusion of the sac (20%). Each time the parent vessel occlusion was associated with the aneurysm occlusion (10 cases), we have never had to deplore any recurrence. A retrospective analysis of those recurrences demonstrates in almost all of them a small remaining neck appearing as a small crescent or triangle of contrast medium at the base of the aneurysm on the immediate control angiogram. 9 of

Table of Anatomical Localizations • • • • • • • • • •

Intracavernous (partially) Carotid-Ophthalmic Post. Communicating Artery Carotid Bifurcation Basilar Artery (tip or trunk) Middle Cerebral Artery Ant. Communicating or Cer. Art. Post. Cerebral Art. P.I.C.A. Subarach. Vert. Art.

7 33 11 12 31 10 13 3 5 3 128

Fig. 1. Schematic Drawings of Endosaccular Techniques for Aneurysm Occlusion

/ / l

Endosaccular "Packing . .

.

.

Endosaccular Clipping . .

.

.

Endosaccular Valving"

S 136 the 18 recurrences underwent a second endovascular treatment (6 of the 9 retreated cases were successfully occluded, 1 patient died from secondary cloting complication after retreatment). 2 of the 18 recurrences underwent a surgical treatment. 3 recurrences are scheduled for a second endovascular treatment. 4 patients bled and died some days or some weeks after the endosaccular treatment and were presenting obviously with recurrences. 4 patients are just kept under angiographic controls because the remnant is small, and stable according to time. These "time stable aneurysmal remnants" set a new concept regarding the understanding of the post endovascular treatment evolution. When a remnant is stable after several control angiograms, we consider it as a p o s t treatment deformation and no more as a recurrence. We have had to deplore 19 complications over 128 cases (15%) which represents in fact 137 different attempts of treatment because of the 9 retreated cases after recurrence. Analysis of those complications reveals 9 deaths and l0 neurological deficits. 8 of the 9 deaths occurred in the posterior fossa localizations: 3 because of brainstem ischemia, and 5 because of aneurysm rupture (1 rupture occurred during the treatment, the 4 other ruptures occurred some days or weeks after treatment because of early recurrence). 1 death is related to a middle cerebral artery embolism which occurred 4 weeks after the endosaccular occlusion. Because no other etiology was demonstrated, we have decided to impute this death to the endovascular treatment. 7 of the l0 neurological deficits are related to cloting phenomena despite the fact that all treatments have been performed under full heparinization. Because of these problems of cloting, we have decided since July 1990 to perform the endovascular treatment under f u l l heparinization associated with an Aspirin therapy (500 mg IV immediately before the procedure) even when the patient is treated in the acute phase of the bleeding. Since this association between Aspirin and Heparine is used, we have not had to deplore any other complication related to cloting phenomena. 2 of the l0 neurological deficits are related to a secondary migration of the balloon (in 1 case we did not repositioned the balloon, in the other one we failed to resposition it). 1 of the 10 neurological deficits occurred after migration of the polymerizing substance because of rupture of the balloon before total solidification of that substance (this was related to the use of a wrong HEMA which caused degradation of the latex balloon, at the beginning of our experience). Analysis of complications we have avoided is also very important as it shows that although we are working remote from the aneurysm itself, we have the possibility of escaping from dangerous situations. Repositioning of the balloon after detachment is one of the major technical tricks that makes the technique safer. In 11 cases a secondary migration of the balloon occurred (it was always some minutes to one hour after detachment), leading to the occlusion of the parent vessel. In 1 case (the first one of our experience) we did not reposition the balloon and we got an ischemic complication. In all of the l0 other cases we repositioned the balloon using a second non detachable balloon catheter. In 9 of those 10 cases, repositioning was successful without complication. In the only case where

repositioning failed, the patient experienced an ischemic complication. Looking at the complications through their percentage of occurrence, one must take into account all the attempts of treatment, that is to say 137 procedures (128 cases + 9 retreatments). The risk of complications is therefore 14% including 6.5% of mortality and 7% morbidity, whatever the localization of the aneurysms is. If we want to compare our results with the neurosurgical one, the anatomiocal localization is very important since it is the only strictly identical parameter between both techniques of treatment. Carotid-ophthalmic and basilar aneurysms are known to be either difficult or dangerous or both regarding the neurosurgical approach. We must consider that those two later localizations represent respectively 26% and 30% of the aneurysms we have treated, this means that the neurosurgical treatment for the same population of patients might have been tricky and/or dangerous in 56% of our cases. Looking at our statistics in more details, one can notice that 39 cases of vertebrobasilar aneurysms (31%0 of the total number of our aneurysms) are responsible for 58% of the total number of complications, while 89 cases of aneurysms in other localizations are responsible for 42% of the total number of complications. If we are now able to avoid complications related to cloting phenomena during the treatment (and it seems that this is possible since we associate heparine plus aspirin), it means that we can expect a reduction of almost 40% (7 over 19 complications) of the overall rate of complications which represents a great improvement. At that stage of our experience the timing of treatment regarding the onset of the hemorrhage versus the clinical results cannot be reliably taken into account because 22 cases treated by endosaccular occlusion in emergency is a too small series. However 6 over the 9 deaths we have to deplore have occurred in emergency treatment, but 5 of them were related to cloting complications which have no special relationship with emergency conditions. Nevertheless the therapeutic traumatism of the endovascular treatment is with no doubt much less important than the neurosurgical one. As a rough conclusion, we can say that according to our experience 71% of intracranial berry aneurysms can be treated by endosaccular occlusion, while 79% can be treated by endovascular approach if we add to the endosaccularly treated cases, the cases where the parent vessel occlusion can be performed. Finally behind the statistical numbers which are absolutely necessary to evaluate the performance of a given technique, it is the philosophy of treatment of berry aneurysms which has changed. Endosaccular occlusion is definitely an alternative treatment whose indications must be discussed in priority for carotid-ophthalmic and basilar aneurysms whatever the circumstances of discovery are. In asymptomatic aneurysms a careful attempt of endovascular treatment carries few risks and seems to be also the first choice of treatment, specially because its failure can be immediately followed by a surgical procedure. In emergency cases, except for the carotid-ophthalmic and basilar localizations, our experience of endosaccular treatment needs to be larger for a more appropriate analysis.

S 137

Endovascular Electrothrombosis of Intracranial Aneurysms Experimental Research and Initial Clinical Applications G. Guglielmi 1'2, F. Vifiuela 2 1University of Rome, Italy, 2University of California at Los Angeles, California, USA In an attempt to improve therapeutic management of patients harboring intracranial aneurysms, a new endovascular technique has been developed during an experimental research and then utilized in selected clinical cases. The occlusive agent consists of a soft, detachable platinum coil, 4 - 4 0 cm in length, soldered to a stainless steel delivery wire. Through a transfemoral microcatheter, already positioned into aneurysmal sac, the platinum coil is deposited into the aneurysm by advancing the delivery wire. A positive direct electric current (0.5 mA) is applied to the proximal end of the delivery wire so that the negatively charged red blood cells, white blood cells, platelets, and fibrinogen are attracted by the platinum coil. By the time a thrombus develops, the current has dissolved by electrolysis, in 4 - 1 2 min, the stainless steel proximal to the platinum coil thus detaching the platinum coil within the clotted aneurysm. Twenty-eight patients with high risk intracranial saccular aneurysms were treated with this endovascular technique. Patients' ages ranged between 21 and 70 years. Eighteen patients were female and 10 were male. Sixteen patients presented with SAH. All patients presenting with SAH were grade I or II but two who were in grade V. Four aneurysms were intracavernous, eleven involved the basilar bifurcation, four the internal carotid

bifurcation, and two aneurysms were carotid-ophthalmic. The remaining aneurysms involved: PICA (two cases), vertebrobasilar junction (two cases), ACoA, MCA, trigeminal artery, SCA and PCoA. Sixteen aneurysms were small, five were large (12 to 25 mm in diameter), and seven were giant. In all 28 cases a consistent amount ( 7 0 - I 0 0 % ) of intraaneurysmal thrombosis was achieved and preservation of the parent artery was obtained in 26 cases. Permanent neurological deficit (hemianopia) was observed in one case. Two patients who were originally in grade V died: one died few days after complete aneurysmal occlusion because of the brain damage due to the initial hemorrhage. The other aneurysm ruptured during the embolization procedure due to probable clot perforation by the microcatheter. This seems to be a promising technique in the treatment of patients having high-risk intracranial saccular aneurysms. A complete aneurysm occlusion can be achieved in small neck aneurysms; same result is more difficult to achieve in wide neck aneurysms because of the potential danger of parent vessel occlusion or coil migration. Long term angiographic and clinical follow up are necessary to critically assess advantages and limitations of this technique.

Angioplasty for Cerebral Vasospasm J. Eskridge Radiology, University of Washington Hospital, Seattle, Washington, USA The mortality from subarachnoid hemorrhage exceeds 50% in the first three months following the hemorrhage. Symptomatic vasospasm occurs in one-third of those who survive the original hemorrhage. A great number of pharmacologic agents and techniques have been tried to minimize spasm. Some of these have been shown to reduce the incidence of symptoms, but once a neurotogic deficit occurred, no treatment was entirely effective. Angioplasty represents a technique to actually reverse a deficit after it has occurred. The basic pathophysiology of cerebral vasospasm involves thickening of the intima and media that results in vasoconstriction. In later stages, the media becomes more fibrotic. Whether or not there is spasm, per se, of the vessel remains controversial. Indirect evidence indicates that the inciting factor for vasospasm is in the erythrocyte component of whole blood and is probably hemoglobin. Spasm typically occurs from days four through ten following the hemorrhage. The first symptom is usually an altered sensorium which can progress to hemiparesis, aphasia, or even coma. The recent development of transcranial Doppler has made it possible to assess the vasospasm noninvasively and to monitor its development over time. Transcranial Doppler provides the earliest clues that vasospasm is occurring. Once spasm starts to

develop, medical therapy including calcium channel blockers, hypertensive, and hypervolemic therapy is started. Patients who are symptomatic from vasospasm are considered for angioplasty if 1) there is recent onset of a deficit that cannot be attributed to other causes such as hydrocephalus or mass effect; 2) the deficit is not reversed by hypertensive and hypervolemic therapy; 3) a recently obtained CT scan does not demonstrate infarction; and 4) spasm is documented angiographically in a location that correlates with the deficit. It is of critical importance to treat symptomatic vasospasm early in order to maximize the chances of improvement. A variety of balloons including silicone, latex, and polyethylene are currently available for performing angioplasty. The technique is done from a transfemoral approach and the patient is usually heparinized. All major vessels including the internal carotid, vertebral, basilar, and proximal anterior, middle, and posterior cerebral arteries are amenable to angioplasty. Angioplasty distal to the proximal portions of the anterior, middie, and posterior cerebral arteries is not safe with present balloon technology. Beyond the proximal portion of these vessels, the balloon becomes much larger than the parent vessel and fatal vessel rupture can occur with balloon inflation.

S 138 The initial results from angioplasty are quite encouraging. At our institution, thirty patients have been treated and twothirds of these have shown sustained improvement following angioplasty which has been defined as either a two grade improvement in motor strength or a two point increase on the Glasgow Coma Scale. In our series of thirty patients, there has been one death and one small middle cerebral infarct directly attributable to the procedure for a morbidity and mortality rate of under 10%.

Long-term follow up has been performed for up to three years and all patients are stable and doing well without delayed complications. Two patients have undergone repeat angiography at three years following angioplasty and the vessels remain normal without long-term damage. Angioplasty is a promising new technique in the battle against vasospasm. Angioplasty should prove to be a major advance in the management of symptomatic subarachnoid hemorrhage.

S 139

Scientific Sessions (ESNR, WFITN)

Moderators: P. Huber, Berne, Switzerland and D. Bal6riaux, Brussels, Belgium

03.30 p m - 05.00 pm

Scientific Papers 134- t43

03.30 pm-05.00 pm Scientific Papers 134-143 134 Localized 1 H NMR spectroscopy in 75 patients with a human brain tumor: Clinical evaluation Ph. Demaerel, K. Johannik, P. Van Hecke, G. Wilms, G. Marchal, Ch. Plets, M. Lammens, J. Goffin, A.L. Baert, Leuven, Belgium 135 Juvenile pilocytic astrocytomas. CT morphology and contrast enhancement G. Huber, M. Hermes, U. Piepgras, Homburg/Saar, Germany

139 Postoperative CT and MR appearance in patients with malignant glioma E. Schindler, K. Heimberger, R. Stiglbauer, K. Kitz, Ch. Spiss, H. Imhof, Vienna, Austria 140 Early postoperative MRGD: A useful basis for monitoring therapy in malignant gliomas E K. Albert, M. Forsting, S. Kunze, K. Sartor, Heidelberg, Germany 141 The role of MRI in brachytherapy of cerebral tumors

136 MRI findings in (so-called low-grade) gliomas unenhaneed by contrast medium. Multicentric study Brussels/Strasbourg (Belgium/France) D. Bal~riaux, C. Aguilera, C. Grand, J. Flament Durand, D. Krause, J.L. Drape, J.B. Jost, N. Heldt, J. Tongio, Brussels, Belgium and Strasbourg, France 137 MRI follow-up of low-grade tumors in young patients. Multicentric study: Strasbourg/Brussels (France/Belgium) D. Krause, J.L. Drape, J.B. Jost, E Jambon, D. Maitrot, N. Heldt, J. Tongio, D. Bal~rianx, C. Agnilera, C. Grand, F. Flament Durand, Strasbourg, France and Brussels, Belgium 138 Leptomeningeal spread of low-grade gliomas: CT and MRI pattern in six cases L. Strada, N. Colombo, M. Savoiardo, G. Scialfa, A. Costa, Milano, Italy

M.G. Bruzzone, V. Longone, C. Giorgi, G. Broggi, A, Costa, M.A. Vaghi, Milano, Italy 142 Use of carboplatin in superselective endoarterial therapy of CNS malignancies M. Leonardi, G. Cartel, A. Lavaroni, L. Clocchiatti, G. Fabris, M. Signor, Udine, Italy 143 Intracerebral tymphoma, neuroradiological appearance K.W. Stock, T. Mueller, E.W. Radue, Basel, Switzerland

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LOCALIZED 1H NMR SPECTROSCOPY IN 75 PATIENS WITH A HUMAN BRAIN TUMOR : :CLINICAL EVALUATION Ph. Demanrel, K lohannik, P. Van Hecke, G. Wilms, G. Marchal, Ch. Piers*, M. Lammens**, J. Goffin*, A.L.Baert, Dept. Radiology, Neurosurgery* and Nearopathology**, University Hospitals K.U. Leuven, Belgium

JUVENILE P I L O C Y T I C ASTROCYTOMAS. C T M O R P H O L O G Y A N D CONRAST E N H A N C E M E N T

The purpose of this study was to evaluate the sensitivity and specificity of 1H spegtroseopy in brain tumors. Seventy-five patients with a primary or secondary tumor were examined with 1H single volume spectroscopy at 1.5 T, using the STEAM method. A histological diagnosis was available in seventy cases. The tumor was localized on a gradient-echo sequence. A volume of interest was chosen centrally in the tumor. Distinct abnormalities were seen in all tumor spectra as compared to the normal brain spectra. For those patients in which a normal brain spectrum could not be acquired, the spectral peak intensities were compared to those obtained in a group of 15 healthy volunteers. A decrease in N-acetylaspartate and/or Phosphocreatine/creatine peak intensities was seen in most tumor spectra as well as changes in the Choline peak. An increased Lactic acid peak was more often observed in malignant tumors. No absolute tumor specific characteristics could be found. A strongly increased Choline peak was a constant finding in meningiomas and oligodendrogliomas. IH spectroscopy is for the moment of limited clinical usefulness and further extensive research is needed, but it is obvious that the technique will contribute to a better insight of brain metabolism.

G.Huber, M.Hermes, U.Piepgras Department of Neurorodiology, Saarland-University, Homburg-Saar, FRG The aim of our investigation was to look for characteristic CT properties (morphology and contrast enhancement) of juvenile pilocytic astrocytomas. In 17 o f 26 patients between 7 months and 13 years with the CT diagnosis o f a brain tumor we found a neuropathologically proven pilocytic astrocytoma WHO grade I. As a characteristic feature the plain CT scan showed a cyclic or polycyclic, hypo- or isodense, distinctly shaped tumor. In contrast to other low-grade gliomas all these tumors expressed an intense contrast affinity. In 13 of 26 patients we found marginal cysts, in two partial calcifications. We never found lctrger perifocal edema. In primarily midline tumors the bilateral extension was by and large symmetrical. Conclusion: Because of its relatively typical C T morphology end its intense contrast affinity it is possible to delineate the cerebral juvenile pilocytic astrocytorma from other brain tumors.

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MRI FOLLOW-UP OF LOW-GRADE TUMORSIN YOUNGPATIENTS MULTICENTRIC STUDY : STRASBOURG/BRUSSELS (FRANCE/BELG!UM)

MRI FINDINGSIN (SO-CALLED LOW-GRADE) 6LIOMAS UNENHANCEDBY CONTRASTMEDIUM MULTICENTRIC STUDYBRUSSELS/STRASBOURG (BELGIUM/FRANCE)

D. KRAUSE; J.L, DRAPE; J, B. JOST; F, JAMBON; D. MAITROT;N. HELDT ; d. TONGIO;D. BALERIAUX; C. AGUILERA; C. GRAND; F.FLAMENTDURAND UNIVERSITY HOSPITALS : STRASBOURGHAUTEPIERRE / FRANCE

D. BNERIAUX ; C. AGUILERA ; 5, GRAND ; J. FLAMENTDURAND D. KRAUSE ; J.L. DRAPE ; J.B. JOST ; N. NELDT ; J. TONGIO Purpose : To evaluate MRI capabilities in grading gliomas of young patients, which are usually considered to be low-grade ( I , I I ) , and are unenhanced by contrast medium, Materials and methods : The tumors observed in these patients (25 cases ; mean age = 38 years) had the following MRI characteristics : - T1 sequences comparable to CT, with i l l defined limits. Constant and marked lengthening of T2 in tumor tissue, with well defined boundaries ; there was no peripheral edema, - Tumor volume was often significant, and better seen on MRI than on CT. - Tumors were almost exclusively located in the frontal and temporal regions. No Gadolinium enhancement. -

-

Results : The significance of this multicentric study lies in detecting a certain heterogeneity of the tumor grades ( I f and I l l ) in the population studied. All tumors were graded according to the WHO classification and independently reviewed by two pathologists.

Purpose, Materials and Methods : The aim of this study was to show the value of MRI in the follow-up of 25 low-grade tumor patients (mostly I and I I , as defined by the WHO classification). The essential feature of these astrocytomas and oligodendrogliomas was the lack of Gadolinium enhancement, Therapeutic indications are s t i l l debated when : - tumor is in a functional area and there are few or no clinical signs ; - tumor evolution is not well understood, as is the case for low-grad~ tumors in the frontotemporal region. Results : MRI in 15 operated patients showed that : T2 sequences had a good sensitivity, allowing differentiation between tumor and surgical sequelae. -a satisfactory post operative status is observed after a mean delay of 36 months (12 patients). - a malignant transormation may occur suddenly, but is detected early on by Gadolinium (3 patients), MRI in 10 unoperated patients showed : marked tumoral progression (increased volume and mass effect) after 30 months (7 patients) ; - unchanged images during a shorter follow-up of 15 - 18 months (3 patients). -

-

Conclusion : The authors underline the d i f f i c u l t i e s in drawing correlations between MRI and histological examinations, in the grading of astrocytomas and oligodendrogliomas in young patients. They found an unexpected incidence of grade I l l tumors (mostly oligodendrogliomas) in a supposedly grade I I population. Is the long-term prognosis affected by unexpected grading results ?

Conclusion : The authors emphasize the value of MRI in the follow-up of low-grade tumors in young patients, Follow-up intervals and correlations with i n i t i a l gradings are s t i l l debated. Gadolinium is essential for detecting loci of malignant transformations.

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LEPTOMENINGEAL SPREAD OF LOW-GRADE GLIOMAS: CT AND MRI PATTERN IN SIX CASES L.Strada, N.Colombo~ M.Savoiardo, G.Scialfa~ A.Costa Department of Nenroradiology , Istituto Nazlonale Neurologlen "C.Besta"-Milano-Italy; =Department of Neuroradiology, Niguarda Hospital- Milano -Italy

POSTOPERATIVE CT A N D MR A P P E A R A N C E WITH MALIGNANT GLIOMA

IN P A T I E N T S

E . S c h i n d l e r I, K.Heimberger I, R , S t i g l b a u e r K . K i t z 3, Ch.Spiss 4, H, Imho? 2

2,

O e p t s . o£ R a d i o l o g y I, N e u r o s u r g e r y 3 a n d Anaesthesiology 4,and M R - I n s t i t u t e 2, U n i v e r s i ty C l i n i c s , W ~ h r i n g e r S O r r e l 18, A - I 0 9 0 VIENNA

Leptomeningeal spread (LMS) of primary Central Nervous System tumors has been described primarily in primitive neuroectodermal tumors, ependymomas and anaplastie gliomas. In low-grade gliomas LMS is extremely rare and the possibility of its oceurence is usually ignored. We observed six cases of low-grade gliomas with LMS at relapse of the tumor; in only one case was LMS present at time of first observation. The tumors were 5 histologically verified oligodendrogliomas and one pilocytic astrocytoma. All cases were studied by pre- and post-contrast CT and MRI. In 3 cases LMS presented as several nodules located mainly in the basal and sylvian cysterns and in the fourth ventricle. In 3 cases diffuse meningeal seeding was observed as linear enhancement associated with nodules located in the intracranial subarachnoid spaces. In one case spinal seeding was observed. Occasionally, subependymal supratentorial spread was also demonstrated. Since all these six cases were collected over a 2 year period, it is obvious that awareness of this possibility helps in recognizing LMS in benign gliomas, wich is probably more eon~non than previously thought.

A s part of p r e p a r a t i o n of a t r e a t m e n t p r o t o c o l for m a l i g n a n t g I i o m a , p o s l o p e r a t i v e CT a n d M R s c a n s a r e e x a m i n e d for r e l i a b i l i t y in differentiating postoperatively remnant neoplasia from traumatic BBB-ma]?unction and postoperative complications. ]0 p a t i e n t s w e r e e x a m i n e d w i t h CT and M R T w i t h i n s t a n d a r d i z e d

140

141

iEELY IK)STOPED/TIVE~ : I I]SEFOLBISIS FOR MONITO]~I(GT~EK~Y IN I(LLIGNANT G'LIOI~. FKAlbertI, ]{ Forsting2, S KunzeI, K Sartor2 iNeuzochirurg. Klinik, 2Meu~oradiol.Abtlg.,Kopfklini}cum,UniversitAtHeidelberg

THE ROLE OF MRI IN BRACHYTHERAPY OF CEREBRAL TUMORS M.G. Bruzzone, V. Longone, C. Giorgl, Go Broggi, A. Costa and M.A. Vaghi Department of Neuroradiology-lstltuto Nazionale Neurologico "C. Baste" MILANO - Italy

In the 0verihelmingmajorityof studiesthat addressthe role of surgeryin the management of high grade- gliomas, the degree of tumor removal accomplished relies solely on the neurusurgeom'sestimetiumat the time of surgery. Despite representingone of the most fundamentalprerequesitesfor comparingdifferent treatment m0dalities, there is a lack of systematic efforts to evaluate the primary residual gross tummm immediatelyafter surgery, by use of modern

neuroimeging. Among the few availableCT- based studiesthere is no consistencyin the methods of assessingresidualtumur volume or in the timing that avoids the ~ell-kn0~m postoperative 'benign'enhancement.At present, comparable}R- studiesare still overdue. We reportthe resultsof a prospectivestudy, startedin march,1989,in which ,~eused contrast-enhancedCr and ~I to monitor60 patientsafter extirpationof a glioblastoma.In eachcase, the first scans wereobtainedbetweenday I through

5 after surgery,consecutivelyfollowedby further examinationseveryt~o to three months, thus coveringthe ~holetime intez-caluntil deathin ~ost cases. @~r results were as follows: - I. Gadolinium-enhanced ~l, when performed during day i to 3 followingextirpationof preoperativelyenhancinghigh gradsglioma, is a valuable method for assessing solid residual t%mor. This timing avoids surgicallyinduced enhancement,and minimizesinterpretativedifficulties caused by artifacts. - 2. ~I is by far superior to C~ in delineatingresidual tumor. - 3. More than eightyper cent of tumor 'rec~rremcies'withinthe first12 months devel0ppedfrom siqMficantlyenhancingremnants,alreadydetectablein the early postoperative~Gd" " 4. Whereasthe surgeon assumedincm~lete extirpation of the gross tumor burden in only 21%, pestopurative~ d revealedsigDificant enhancement in 76 %. - 5. Residual tumor enhancement is the m0st predective pro~musticfactor in our stillongoingstudy.

postoperative

intervals

(I-3

days, I0 days, 6

~ e e k s ) to v e r i f y the a c t u a l s i z e of postoperative n e o p l a s i a r e s t , and to make chemotherapy and irradiation effects c o m p a r a b l e . N e a r l y a l l exams done i-3 days postoperative, w e r e m a d e under c o r t i s o n e

treaimenl. site

Hemorrhage i n t o

impedes

glioma.

the e v a l u a t i o n

the p o s t o p e r a t i v e o? s i z e

o? r e m n a n t

CT exams done more than t h r e e days

postoperative show marginal hyperdensity on c o n t r a s t enhancement, m a k i n g d i a g n o s i s of tumor rest m o r e d i f f i c u l t or i m p o s s i b l e . Postoperative MRI, d o n e e a r l y in the postoperative course, reveals good delineation

o f remnant n e o p l a s i a .

Between February 1988 and March 1991, sixty patients underwent stereotactic brachytherapy with removable high activity iodine-125 seeds, for neureepitellal tumors (49 cases), pituitary adenomas (5 cases), craniopharyngiomas (4 cases), metastasis (I case) and meningiomas (lease). MR imaging was performed before and after the procedure and serial controls were executed in association with neurological examination, every six months from the day of the implantation. MRI seems to be a feasible technique to outline~ in different planes, the target volume and isodose contours in order to optimize the catheter placement and to obtain an adequate coverage of the tumor sparing healty structures Moreover DLRI is useful for successive controls to evaluate modifications of tumor volume, the development of necrotic cysts and the occurrence of madame.

S 142

142 USE OF CARBOPLATIN IN SUPERSELECTIVE ENDOARTHERIAL THERAPY OF CNS MALIGNANCIES M. Leonardi, G. Cartel*, A. Lavaroni, L. Clocchiatti* G. Pabris, M. Signor* Servizio dl Neuroradiologia, *Divisone di Oncologia 0spedale Civile di Udine, Italy i0 males and 10 females, aged 17 to 65 years underwent superselective endoartherial chemotherapy with carboplatin because of glyoblastoma (I0), astrocitoma (4), metastasis (6), between them.. 5 patients had surgery with residues, 4 were in relapse after radical surgery, 5 had diagnosis by CT alone. Object of the study was: dose searching, toxicity evaluation, therapy effectiveness evaluation. Carboplatin injection in the supraophtalmic carotid syphon or directly in the midlle cerebral or anterior cerebral arteries avoided retinal injury with maximal concentration of the drug in the feeding vessel. Dose was of 200 mg for Carboplatin combined with sistemic chemotherapy (9M26, BCNU, CCNU, Solumedrol) every 4 weeks and 300 mg every 2 weeks for Carboplatin alone; Carboplatin was injected in 30 min. diluted in saline (250 ml). Two episodes of reversible emiparesis were observed not precluding further chemotherapy, probably due to angiographical problems. Cycles performed were 65: i to 4 (m2) for each patient. Results in 19 evaluable patients were quite difficult to be identified, response duration (Partial Remission and Stable Disease) varying from 9 to 54 weeks. A positive response was felt by researchers and a more wide and prolonged study is under program.

143 INTRACEREBRAL LYMPHOMA, NEURORADIOLOGICAL APPEARANCE K.W. Stock, T. Mueller, E.W. Radue lntracerebral lymphoma of 40 patients (mean age 61 years) are studied and the CT, MRI and angiographic findings are demonstrated. The typical lymphoma is a hyper- or isodense (86%), solitary (68%) lesion in CT with contrast enhancement in all tumors which are homogenous in 80%. In MRI the lesions are isointense in T1 weighted images with dens enhancement in all of them and hyperintense in T2 weighted images. Cerebral angiography showed pathological arteries in 31% and a tumor blush in 13%. Follow up studies are presented after radiotherapy or chemotherapy. Atypical lesions are also demonstrated. Although cerebral lymphoma have a rather typical appearance in CT, MRI and angiography, one has to think of them in almost every cerebral tumor not only in AIDSpatients but also in old age patients.

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Concurrent Scientific Session (WFITN): Aneurysms Moderators: L. Picard, Nancy, France and A. Fox, London, Canada

03.30 p m - 05.00 pm

Scientific Papers 144-154

03.30 pm-05.00 pm Scientific Papers 144-154 144 A retractable coil for the treatment of aneurysms M. P. Marks, G.K. Steinberg, H. Chee, B. Lane, Stanford, USA 145 Endovascular treatment of 16 intracranial aneurysms with microcoils J.P. Pruvo, X. Leclerc, G. Soto Ares, H. Deramond, J. Clarisse, Lille, France 146 Endovascular treatment of small intracranial aneurysms with microeoils A. Rogopoulos, A. Casasco, Y.P. Gobin, P. Paquis, P. Grellier, J.L. Roche, E. Houdart, C. Aboulker, Nice, France 147 Transarterial platinum coil embolization of aneurysms L.A. Lemme-Plaghos, C.J. Schonholz, A.L. Ceciliano, Buefios Aires, Argentina 148 Staged endovascular treatment of cerebral aneurysms with coils D. Ktihne, H.C. Nahser, Essen, Germany 149 Endovascular therapy of aneurysms with platinum coils following subarachnoid hemorrhage A.J. Fox, S. E Lownie, C.G. Drake, London, Canada

150 Endovascular treatment of intracranial aneurysms with the GDC electrocoH

A, Berenstein, I.S. Choi, J. Jafar, M.J. Kupersmith, New York, USA 151

Endovascular treatment of surgical and nonsurgical intracerebrai aneurysms with metallic coils A. Casasco, A. Rogopoulos, A. Aymard, Y. P. Gobin, J. E. Hodes, D. Reizine, B. George, J.J. Merland, Paris, France

152 Occlusion balloon suction decompression of supraclinoid carotid anenrysms: Work in progress J.A. Scott, Indianapolis, USA 153 Embolization of intracranial aneurysms: Technical problems, MRI changes and results L. Lopez Ibor, M. de la Fuente, B. Anciones, C. Diaz, Madrid, Spain 154 Endovascular treatment of mycotic cerebral aneurysms A. Aymard, D. Herbreteau, M. Khayata, A.L. Bailly, E Woimant, A. Casasco, J.J. Merland, Paris, France

s 144

145

144 A I~2~TR&CT~I~ COIL FOR ~ TIE~A~NT ANEURYSMS MP Marks, GK Steinberg, H Chee, B Lane Stanford University Medical Center

OF

Thrombogenic coils have b e e n u s e d in t h e t r e a t m e n t of s a c c u l a r a n e u r y s m s , b u t r i s k s in their delivery include e r r a n t release, release in a n o n c o m p a c t s h a p e , a n d d i s p l a c e m e n t b y flow. T h i s s t u d y evaluated a retrievable coll t h a t would r e d u c e t h e s e risks. A n e w thrombogenic coil w h i c h is m e c h a n i c a l l y d e t a c h a b l e from t h e coil p u s h e r w a s d e s i g n e d w i t h multiple c o m p l e x s h a p e s . S h a p e s varied d e p e n d i n g o n t h e size of t h e a n e u r y s m treated. T h i s w a s tested in a n fin vitro glass model s y s t e m with a variety of side wall a n d bifurcation a n e u r y s m s , varying from 5 to 10 m m . Coil design w a s t h e n tested in a rabbit a n i m a l model w h e r e a bifurcation a n e u r y s m w a s created with a vein p o u c h after a n a s t o m o s i s of t h e carotid arteries. Smaller a n e u r y s m s in t h e fin vitro model were treated with a complex flower design. Longer coils would n o t m a i n t a i n this s h a p e a n d a circular s h a p e w a s preferable. T h e coll could b e released u p to 90% of its l e n g t h a n d still be effectively retrieved into t h e delivery catheter. In t h e a n i m a l model, a n e u r y s m s from 4 to 10 m m in diameter were produced. T h e s e s m a l l e r a n e u r y s m s were coiled utilizing t h e retractable coil. W h e n t h e coil p r o t r u d e d into t h e p a r e n t vessel it could be retrieved w i t h o u t detachment. A retractable coil s y s t e m h a s b e e n d e m o n s t r a t e d t h a t allows release within a n e u r y s m s a n d t h r o m b o s i s of a n e u r y s m s in fin vitro a n d fin v(vo settings. U s e of t h e retrievable coil provides a m a r g i n of safety a n d control n o t available with conventional c o t s y s t e m s .

ENDOVASCULAR TREATEMENT O F 16 I N T R A C R A N I A L ANEURYSMS WITH MICROCOILS. J.P. PRUVO, X. L E C L E R C , G. S O T O ARES, H. D E R A M O N D , J. C L A R I S S E . S i n c e 1989, 16 p a t i e n t s p r e s e n t i n g w i t h an intraeranial aneurysm were embolised using microcoils Selective catheterisme was performed by m e a n s of a 18 gauge traker catheter. Anevrysmal occlusion was achieved after insertion of the c a t h e t e r tip into the distal part of the aneurysm and i n j e c t i o n of H i l a l and Target therapeutic microcoils of decreasing size until o b l i t e r a t i o n of the n e c k of the a n e u r y s m . In II cases endovascular treatment h a d p e r m i t t e d the c o m p l e t e o c c l u s i o n of the v a s c u l a r m a l f o r m a t i o n at 6 m o n t h f o l l o w up. (7 aneuryms of the basilar trunck, 4 a n e u r y m s of the c a r o d i d siphon). In 4 c a s e s the t r e a t m e n t was o n l y partial. F i n a l l y in i case, f a i l u r e w a s due to the large size of the neck of the aneurysm.

3 patients had a regressive complete motor p a r a l y s i s due to the d i s t a l migration of a microcoil beyond the aneurysm. Aneurysms in the vascular flow, mult ilobulated and small aneurysms represent, in our opinion, the best i n d i c a t i o n o f this t e c h n i q u e .

146

147

ENDOVA~CULAR TREATMENTOFSHALLNTRAORANIALANEURYSM$WiTH

TRANSARTERIAL PLATINUM COIL EMBOLIZATION OF ANEURYSMS.

MIC~0C0IL$

LA kemme-Plaghos, CJ Schonhoh, AL Ceciliano.

A. R0gepoul~,A. Ca.c~so),Y.P.Gobtn,P. Paquls,P. Orellier, d.k. Roche,E. Houdart,O.Abeulker Service de gadiologie et de Neurochirurgie, Centre Hospltailar de NICE

PURPOSE : Four patientswith small ruptured Intraorantal aneurysms (less than 5 mm diameter) were treated by embolleatlon with mlorocolls, METHODSAND MATERIALS : We have chosen end0vas~ular treatment because of contraindlcatlons of surgery. Contraindlcatlons were anatomical (2 cases),dueto generalstatus (a 77 yearsold patient), or religious ( I case). The aneurysms were located on the ¢arotlco-ophtalml¢ artery (1 case,) and on the anterior communicating artery (3 cases),All of them were embollzed with platinum microcolls (Target Therapeutic) after selective catheter ism of the aneurysms w i th a Tracker 18 ( Target Therapeutic). All the proceduresweredonebyfemoralroarandunderlocal anaesthesia. RESULTS:Theocclusionof the eneurysmswascompletein threeoasesand almost done In one. No recurrence of bleeding nor repermeetlen of aneurysm occurred. One transient leg paresis occurred, but no definitive complication was observed, tr, particular, no mental impairment was observed after the treatment of the three anterior communicating artery aneurym'ns. CONCLUSION: On thls limited number of patients, emboltsatlon with coils ofsmallaneurysmsseems efficientand ~fe,We actuallyappliedthistechnic topatientswhom surgeryIsnot possibleor notcafetyfor,Ifthlsgoodresults are cenfirm~,endovasculartreatmentwlth ceilsshould be extendedto the treatmentofellIntracranialsmallbarryaneurysms.

Neuroradiology Section, University Hospital and Neuroradiology Section, Cl~nica del Sol, Buenos Aires, Argentina. Transvascular platinum coil technique of embolization relies on the "packing" and/or thrombotic delayed pheno~ mena observed after their placement through superselective coaxial catheterization, already reported in certain vascu lar and dural arteriovenous malformations. We report a series of eleven cases of intracranial aneu rysms (6 large intracavernous aneurysms, 3 in the vertebro basilar t e r r i t o r y and 2 in a supraclinoid location) in which transarterial coil embolization (Flower Coils and He licoidal Coils, Target Therapeutics) was pePformed due to previous surgical or dettachable balloon failure. Although all the intracavernous aneurysm wePe incompletely f i l l e d in with coils due to their large size, subtotal Occlusion wasddentified in the follow up of three ca ses and complete occlusion with preservation of the parent artery was observedin other two. One case bled inmediate ly after the embolization proccedure and died. Out of the 5 aneurysms with sizes less than 15 mm, 4 were completely packed in with coils showing complete occlusion in the follow up while the f i f t h one had revascularization of the neck where a complementary ~ettachable balloon had been positioned. These results show that the this technique may be an alternative indication for intracranial aneurysms but deve lopment of larger and longer retriebable coils is needed to obtain better results with complete occlusion in large and giant aneurysms.

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148 STAGED ENDOVASCULARTREATMENT OF CEREBRAL ANEURYSMS WITH COILS

149 ENDOVASCULkRTHERAPYOF ANEURYSMSWITH PLATINUM COILS FOLLOWINGSUBARACHNOIDHEMORRHAGE AJ Fox, SP Lownie, CG Drake, University Hospital, London, Canada

Selective balloon occlusion of cerebral aneurysms with other locations than the cavernous parts of the carotid a r t e r y carries the r i s k of reopening by wandering of the balloon in the thrombus or by a valve mechanism that leads to enlargement or bleeding of the aneurysm. The implant a t i o n of thrombogemic c o i l s seems to be a reasonable a l t e r n a t i v e for selective aneurysm occlusion, In our protocol of a multistaged approach 2 b a s i l a r , 2 suprac l i n o i d c a r o t i d , I c a r o t i d cavernosal, I c a r o t i d b i f u r cation and I ACom.ant.aneurysm have been treated. The number of sessions ranged from two to f i v e . There were transient neurological d e f i c i t s recorded in two patients during treatment. One coil d i s l o c a t i o n did not lead to neurological d e f i c i t s . In the f o l l o w up period there have been no f u r t h e r hemorrhages and neurological d e f i c i t s due to mass e f f e c t of giant aneurysms improved, In conclusion staged c o i l implantations of unclippable aneurysms of cerebral a r t e r i e s o f f e r a promising a l t e r n a t i v e . However our patients have to be c l i n i c a l l y followed c a r e f u l l y to obtain f u r t h e r results.

PURPOSE: To evaluate ease, safety, and effieaey of using complex helical platinum coils for cranial aneurysms following subarachnoid hemorrhage. MATEPJALS & METHODS: 5 patients were treated with intraaneurysmal coils following hemorrhage, 4 acutely and 1 delayed. The delivery catheter was a Tracker 18. Patients were followed clinically, and in I case by autopsy. Patients had either unclippable aneurysms or a Grade IV clinical state. RESULTS: Coils (2cm-6cm long) were able to be placed within the aneurysm sac, totaling 23-70 em in individual cases. In no case did a coil go astray. The vast majority of the aneurysm sac was filled, and, in the 3 with delayed angio, thrombosis around and between coils was demonstrated. No patient suffered a repeat hemorrhage during the follow up period up to 9 months. All patients had aneurysmal neck remnant. One case showed aneurysm neck regrowth to a larger aneurysm than originally. CONCLUSIONS: Platinum coils are easy to place into aneurysms and can be placed without serious risk of mechanical rupture. Inadvertent embolization of the parent vessel can be avoided. Platinum coils can induce thrombosis if the coil mesh is tight enough. This technique is useful for adding protection the acute stage, for patients who are not candidates for surgery. Continuing follow up and additional treatment as appropriate is necessary because the treatment is not a complete cure.

150

151

D. KOHNE, H.C. NAHSER

ENDOVASCULAR TREATMENT OF INTRACRANIAL ANEURYSMS WITH THE GDC ELECTROCOIL A.Berensteln, l.S.Choi, J.Jafar, M.J.Kupershmith New York University Medical Center, New York, USA The endovascular treatment of cerebral aneurysms is in an elvolvlng stage. Balloons were the first utilized devices. More recently metallic coils with or without fibers have been used in an attempt to obliterate aneurysms. Various problems exist with these agents. The development of the GDC, a detachable call system that employs electrocurrency, eliminates most of the problems encountered with all other agents, permitting an easy, safe, reliable and reproducible technique for [ntraluminal aneurysm obliteration. We have successfully treated 4 aneurysms in 3 patients with the GDC coil, obtaining complete obliteration in all cases without complications. The aneurysm size varied from 5 mm to a 6 cm lesion with a wide neck. A follow-up angiogram of at least one week postoperatively confirmed the aneurysm obliteration in all and intraoperotive confirmation of occlusion is available in one. Our early results are very encouraging. Long term follow-up is needed, and if long lasting, this technique will revolutionize the treatment of all patients with cerebral aneurysms.

Endovascular Treatment of Surgical and Nonsurgical lntracerebral Aneurysms with Metallic Coils A Casasco, A Rogopoulos, A Aymard, YP Gobin, JE Hades, D Reizine, B George, JJ Merland Lariboisi~re Hospital, Paris, France We report results of transvascular intra-aneurysmal placement of platinum minicoils for treatment of small (<15mm) intracerebral aneurysms. From 1/90 to 5/91 we treated 16 patients (10F, 6M) with small !ntracerebral aneurysms. Localization included 3 carotid ophthalmic, 1 carotid bifurcation, 3 MCA bifurcation, 3 anterior communicating, 3 posterior cerebral, 1 basilar tip, and 2 PICA origin aneurysms. Presentation: 5 asymptomatic (grade 0 Hunt and Hess), 11 SAH (four grade 1, four grade 2, and three grade 3). Treatment: Superselective catheterization of the aneurysm with a microcatheter followed by placement of minicoils in the aneurysm lumen. Results: Angiographic: Complete (12) or partial [(9095%) (4)] aneurysm exclusion: Follow-up: 1-18 months (mean 7). Clinical: Excellent results: 14. One asymptomatic patient had transient (one mont h) third nerve palsy following treatment of her PICA origin aneurysm. One other patient presenting after SAH had an embolic MCA infarct. No rebleeding in the 4 partially treated patients (2-18 month of follow-up). Selective e n d o v a s c u l a r t r e a t m e n t of small aneurysms with minicoils is a technique that seems effective, relatively simple, and reproducible. More patients may benefit from this treatment, which would allow us to compare our series with surgical results.

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152

153

0CCLUSIONBAI//3ON SUCTION DECOMPRESSION OF SUPRACLINOID CAROTID~YSMS: WORK I N ~ S J.A.Scott Department of Radiology, 1701 N.Senate, Indianapolis, Indiana, USA

EMBOLIZATION OF INTRACRANEAL ANEURYSMES: THECNICAL PROBLEMS, MRI CHANGES AND RESULTS.

Supraclinoid carotid aneurysms are often difficult to surgically clip. We have developed a t e c ~ q u e to deccmpress the aneurysmat the time of surgery, aiding in dissection and clipping. The cervical internal carotid artery is occluded w i t h a double-l~z~enocclusionballoon catheter. The distal carotid is temporarily clipped proximal to the posterior cc~aunicating artery. The "trapped" vessel segment, including the aneurysm, is decompressed by gentle aspiration through the distal lumen of the catheter. This maneuver collapses the aneurysm allowing for easier dissection and clipping. To date, we have treated 12 patients using this technique. There has been one cc~nplication of monocular blindness.

C1Enica La Zarzuela.

AUTHORS: L. Lopez Ibor; M. de la Fuente; B.Anciones; C. Diaz.

We review 12 cases in 11 patients with intracraneal Aneurysmes with these locations, in the time Nov. 86 -

Feb. 91. 5 Cavernous Sinus 1 Carothin siphon C1-C2 segment 2 Posterior .Comunicent a r t e r y (1 same patient) 2 Middeld cerebral artery 1 Posterior Cerebral a r t e r y 1 Basilar Artery We discuss the technical procedures during embolization, the complications and incidences, We describe the signal aspects in MRI recated,to flow partial thrombosis, parietal changes and effects

on cerebral tissue. Succeful embolization was carried out in 9 cases, and in 3 cases have thecnical problems, 1 case was surf i c a l l y clipped, and anothen 2 They were followed up with early and delayed postembolization MRI and angiographic studies.

154 ENDOVASCULAR TREATMENT OF MYCOTIC CEREBRAL ANEURYSMS A Aymard, D Herbreteau, M Khayata, AL Baiily, F Woimant, A Casasco, JJ Merland Dpt of InterventionalNeuroradiology,Ladboisi~reHospital,Paris, France We evaluated the endovascular treatment of intracranial mycotic aneurysms. The clinical and angiographic features of three patients with endocarditic vegetations (2 Steptococcus Viridans, 1 Staphytoccocus ) were retrospectively reviewed. Patients were selected for treatment by consultation with n e u r o s u r g e o n s and n e u r o r a d i o l o g i s t s . Selective catheterization of a distal middle cerebral and posterior cerebral artery branch with a micro-catheter (in two cases) followed by superselective Amytal testing of the parent vessel was preliminary to the occlusion of that vessel.with autologous clot or glue. The third patient was treated by selective occlusion of the aneurysm by intraaneurysmal placement of platinum minicoils. Two patients had intracranial hemorrhage and the third had an incidental lesion discovered at routine angiography. All three aneuryms were excluded from the circulation. There were no complications from the procedure despite the septic nature and distal Iocalisation except for one balloon deflation that required successful retreatment with coils. Endovascular embolisation is indicated in these patients that are at risk of hemorrhage, and avoids surgery. The superselective Amytal test allows selection of patients that will tolerate distal vessel occlusion. This procedure is safe and effective for these lesions.

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Concurrent Scientific Session (ESNR): Intracranial Tumors - 2 Moderators: E. Cabanis, Paris, France and M. Nadjmi, Warzburg, Germany 08.30 a m - 10.30 a m

Scientific Papers 1 5 5 - 1 6 9

10.30 a m - 11.00 a m

C o f f e e Break

08.30 am-lO.3Oam Scientific Papers 155-169 155 Intracranial meningioma: Correlation between MRI and histology in 60 patients at 1.5 T Ph. Demaerel, G. Wilms, M. Lammens, C. Plets, J. Goffin, A.L. Baert, Leuven, Belgium 156 Meningiomas: Multiplicity and associated intracranial masses W.O. Bank, 13. Bal6riaux, U. Salvolini, Ph. David, L. Salvolini, O. Dewitte, ]3. Pirotte, Brussels, Belgium/ Ancona, Italy 157 Preoperative evaluation of embolized meningiomas with gadolinium enhanced MRI C. Grand, D. Bal6riaux, W. O. Bank, C. Matos, J. Brotchi, O. Dewitte, C. Delcour, Brussels, Belgium

163 Neuroradiologic evaluation of craniopharyngiomas E Di Salle, L. Simonetti, R. Morrone, S. Cirillo, R. Spaziante, E. de Divitiis, R. Elefante, E Smaltino, Naples, Italy 164 Cystic intracranial schwannomas C.J. Wallace, T.C. Fong, Calgary, Canada 165 Flow MRI: Applications in acoustic neurinomas D. Krause, J.L. Drape, V. Bosser, D. Maitrot, J. Tongio, Strasbourg, France 166 Regrowth potential of acoustic neuroma fragments remaining after surgery-assessment by MRI J.E. Gillespie, R.H. Lye, A. Pace-Balzan, R.T. Ramsden, J.M. Dutton, Manchester, United Kingdom

158 Extended microembolization of cranial meningiomas A.K. Wakhloo, M. Schumacher, V. van Velthoven, R. Scheremet, K. Schwechheimer, J. Hennig, Freiburg, Germany 159 Role of enhanced MR in differentiating sellar meningioma from pituitary adenoma M.A. Mikhael, Evanston, USA 160 MRI in meningioma of the periseilar region and base of the skull L. Lopez Ibor, M. de la FUente, C. Perez Cuadrado, J.G. Martin Rodriguez, Madrid, Spain 161 MRI diagnosis of pituitary microadenomas E Briganti, A. Manto, E Spadetta, M. Menditto, S. Cirillo, R. Elefante, E Smaltino, Naples, Italy 162 Pituitary apoplexy. Clinical and imaging considerations M.A. de Miquel, J.M. Fernandez Real, J.J. Acebes, H. L. Espinet, J.L. Monfort, A. Muntane, J. Soler, L.C. Pons, Barcelona, Spain

167 Gadolinium enhancement of the cisternal portion of the oculomotor nerve: Clinical and pathological significance A.S. Mark, P. Blake, M. Ross, S. Atlas, D. Brown, Washington, USA 168 Contribution of 3 dimensional imaging to the examination of skull base tumors C. Louail, M. Raynaud, 13. Gense de Beaufort, J. E Gr6selle, J.M. -C-aill6, Bordeaux, France 169 Magnetic resonance imaging of the central nervous system in children - indications and usefulness K.-A.. Thuomas, K. Bergstr6m, G. Ahlsten, M. Dahl, K. Sj6rs, Uppsala, Sweden

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155 INTRACRANIAL MENINGIOMA : CORRELATION BETWEEN MRI AND HISTOLOGY IN 60 PATIENTS AT 1.5 T Ph. Demaerel, G. Wilms, M. Lammens*, C. Plots**, J. Goffin** A.tBaert, Dept. Radiology, Neuropathology* and Neurosurgery**, University Hospitals K.U. Leuven, Belgium The purpose of this study was to analyze the signal intensities of intracranial meningiomas and to correlate these with the different histologic subtypes. The average signal intensity on spin-echo T1, proton density and T2 weighted images was determined in 60 surgically confirmed meningiomas at 1.5 T. The same visual scoring system as Elster was used for this purpose (1). Additional features, as the presence of calcifications, peritumoral edema and cyst formation, were evaluated too. The results were correlated with each other, using the student-t-test. Only the proton density and T2 weighted images provided some useful information. However, 47% of the meningiomas remained still unclassifiable. Only one significant (psammomatous-anaptastic) and three almost significant correlations (syncytial-transitionat or psammomatous and transitional-psammomatous) were found. Different histologic subtypes may have a different MR appearance, but this does not suffice to confidently determine the histologic subtype on MRI. (1) Meningiomas : MR and histologic features. Elster AD, Challa VR, Gilbert TH, Richardson DN, Contento JC. Radiology 1989; 170:857-862

157 PREOPERATIVE EVALUATION OF EMBOLIZED MENINGIOMAS WTrH GADOLINIUM ENHANCED MRI. C. G r a n d i, D. Bal~riaux ~, W.O. B a n k i C. Matos ~, J. Brotchi a, O. Dewitte a, C. Delcour 2 D e p a r t m e n t s of Neuroradiology ~, Angiography 2, a n d Neurosurgery 3; H6pital Erasme, Universit6 Libre de Bruxeiles, Brussels, Belgium.

Purpose: Neither CT s c a n n i n g n o r angiography provide consistently reliable evaluation of the efficacy of preoperative embolization. Since this information is i m p o r t a n t to the planning of b o t h the surgeon a n d anesthesiologist, we investigated t h e value of gadolinium e n h a n c e d MRI for this purpose. M a t e r i a l s a n d M e t h o d s : Eight patients with m e n i n g i o m a s were prospectively studied. Four factors were evaluated to determine t h e efficacy of the preoperative embolization: 1. relative percentage of the tumor's v a s c u l a r supply arising from the internal a n d external carotid arteries; 2. percentage of t u m o r embolized as judged by angiography, gadolinium e n h a n c e d MRI, a n d (in 3 cases) by CT; 3. estimated blood loss (EBL) during t u m o r excision; a n d 4. h i s t o l o g i c e v i d e n c e of n e c r o s i s a s s e e n b y t h e neuropathologist. R e s u l t s : Good correlation existed between the m e t h o d s in 7 of the 8 cases. In one case, MRI d e m o n s t r a t e d clear superiority to CT a n d angiography. Conclusion: Gadolinium e n h a n c e d MRI is a n excellent m 0 d a l i t y for e v a l u a t i o n of t h e efficacy of m e n i n g i o m a embolization due to the i n h e r e n t sensitivity of MRI a n d its ability to d e m o n s t r a t e t u m o r e n h a n c e m e n t adjacent to bone, a n d due to the fact t h a t the s t u d y c a n be performed immediately post embolization without interference from the iodonated c o n t r a s t material injected during the embolization procedure.

156 MENINGIOMAS: MULTIPLICITY AND ASSOCIATED INTRACRANIAL MASSES. W.O. B a n k i, D. Bal~riaux i, U. Salvolini 3, Ph. David i, L. Salvolini ~, O. Dewitte a B. Pirotte 2 D e p a r t m e n t s of Neuroradiology i a n d Neurosurgery2; H6pital Erasme, Universit~ IAbre de Bruxelles, Brussels, Belgium, a n d D e p a r t m e n t of Neuroradiology 3, Ospedale Generale Regionale, Ancona, Italy. P u r p o s e : Meningiomas are k n o w n to be t u m o r s t h a t are not infrequently multiple a n d not infrequently associated with o t h e r intracranial lesions. The p r e s e n t review was u n d e r t a k e n to b e t t e r u n d e r s t a n d these aspects of meningiomas. M a t e r i a l s a n d M e t h o d s : A retrospective review was perf o r m e d o n all p a t i e n t s e v a l u a t e d a n d / o r t r e a t e d for m e n i n g i o m a s a t two major teaching hospitals from 1965 until t h e present. R e s u l t s : The incidence of multiple menigiomas a n d the association ofmeningiomas with other intracranial pathology was documented. The advent of CT a n d s u b s e q u e n t l y of MRI u n d o u b t a b l y accounts for the a p p a r e n t increase in frequency of the diagnosis of multiple lesions over the time period studied. Meningiomas were seen in association with gliomas, n e u r i n o m a s , h e m a t o g e n o u s m e t a s t a s e s a n d aneurysms. The role of different imaging modalities in the differentiation of the various lesions will be discussed. Conclusion: Refinements in MR technology, the use of paramagnetic contrast agents, a n d the ability to visualize the "tail sign" in a t l e a s t one plane of evaluation, give this modality the leading (but not exclusive) role in the diagnosis of multiple m e n i n g i o m a s or m e n i n g i o m a s a s s o c i a t e d w i t h o t h e r intracranial tumors.

158 EXTENDED MICROEMBOLIZATION OF CRANIAL MENINGIOMAS A.K.Wakhloo (1), M.Schumacher (l) s V.van Velthoven (2), R.Scheremet (2), K.Schwechhelmer (3), J.Hennig (4) Section of Neuroradiatogy (1), Departments of Neurosurgery (2), Neuropathology (3) and Radiology (4), University of FreiburgI Freiburg i.Br., FRG In 18 patients with convexity menlnglomas and meninglomas of the skull-base, MRI, MR1H-spectroscopy, intraoperative ultrasound and hlstopathologlcal findings were examined with respect to effectiveness of preoperative PVA-particle embolization. A micro-catheter system was introduced in feeding vessels generally arising from the external carotid artery. In those cases with feeding arteries arising from the tentorial artery the embolization was carried out with temporary balloon occlusion of the internal carotid artery. Two different embolizatlon techniques were performed: 1. administration of 150-300p, m PVAparticles in usual suspension and embollzation time, 2. administration of 50-150/~m PVA-partieles in extremely diluted suspension and extended embolization time, upto to 1.5 h for each feeding vessel. The post-embolization angiography demonstrated the total elimination of the tumour blush in all patients. However, MR images performed 5 days after the embollzotlon revealed a significant tumour necrosis only in those cases in whom the second technique was applied. Upto 95~ of whole turnout was necrotic with significant reduction of mass effect. Administration of 150-3007¢n PVA-particles did not yield any substantial effect on tumour vascularization demonstrated on contrast enhanced MRI. The MR1H-spectroscopy of meningioma after embolization showed an increase of lactat indicating ischemlc necrosis of turnout. Surgery performed 5-I0 clays after embolization showed an easy removal of effectively embolized meningiomas with no significant blood loss. Intraoperative tumour aspect and ultrasound as well as the histopathological examination from different turnout regions confirmed the preoperative MRI findings. Extended micro-embollzatlon with PVA-particles improves the tumour excision. An embolization of menlnglomos may be the only therapeutic intervention in old and high-risk patients.

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159 ROLE OF ENHANCED MR IN DIFFERENTIATING SELLAR MENINGIOMA FROM PITUITARY ADENOMA M.A. Mikhael Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois PURPOSE: To evaluate the differentiating criteria on MRI scans between sellar meningioma and pituitary adenoma because of different approach for surgicalremoval. MATERIALANDMETHODS: Of the 656 MR studies for suspected sellar/supraseUar masses, 52 small and 38 large sellar/supraseUar pituitary tumors, together with 26 meningiomas were diagnosed and surgically removed. MR studies ineluded sagittal and coronal contiguous slices, 3 mm thick, before and after Gd-DTPA enhancement (SE: TR 600 ms, TE 20 ms). RESULTS: Small pituitary adenomas and large pituitary tumors with no constriction at diaphragma sella¢, are removed through transsphenoidal approach. On the other hand, meningiomas are removed through transcranial approach, not to risk removal of the normal pituitary gland and incomplete removal of the meningioma. So it is important to differentiate between sellar meningiomas and pituitary tumors before surgery. Although enlargement of seUa and hyperprolactinemia am in favor of pituitary tumors, intrasellar/suprasellar meningiomas can mimic pituitary adenomas (2 cases in our series), and large pituitary adenomas can have normal sellar size and no hormonal dysfunction. Post-enhanced MR augmented differentiating criteria between the two lesions: 1) Dense enhancement of noncalcified meningioma, 2) No enhancement of small and medium-sized pituitary adenomas, and moderate enhancement in large tumors, 3) Facilitates visualization of diaphragma sellae, which delineates meningioma from pituitary gland, 4) Facilitates visualization of tumor and surrounding structures, such as bones, an important finding for diagnosis of meuingiomas. CONCLUSION: Post-enhanced MR scan is needed for the diagnosis and differentiation between sellar/suprasellar pituitary tumor and meningioma.

160 MRI IN MENINGIOMA OF THE PERISELLAR REGION AND BASE OF THE SKULL AUTHORS: L. Lopez I bor ; M. de l a Fuente; C.Perez Cuadrado; J.G. Martin Rodriguez. Clfnica La Paloma. We present 44 cases with perisellar meningiomas located in the walls of the cavernous sinus ( 8 cases), in the Gasserian ganglion and retrosellar region ( 9 cases) , Mayor wing of the sphenoid (8 cases), anterior clinoids (2 cases), cerebellopontine angle (6 cases), occipital foramen and clivus (5 cases) and one patient with diffuse meningiomstosis affecting the base of the skull. MRI has adventages over CT owing to the facts that a)MRI delineates better the anatomic boundaries by using multiplanar sequences. b) NRI diferentiates the perilesional vasogenic edema from the tumoral nidus. c) MRI allows the visualization of an hypointense pseudocapsule related to compressed. subsrachnoid space, dura, ressels and fibroid tissue. After the introduction of paramagnetic contrast medium (gadolinium) an homogeneus enhancenet can be obser red which can help in the preccocious detection of tumor recurrence and meningiomatosis.

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MRI D I A G N O S I S OF P I T U I T A R Y M I C R O A D E N O M A S F . B r i g a n t i , A. Manto, F. S p a d e t t a , M. M e n d i t t o , S. C i r i l l o , R. E l e f a n t e , F. S m a l t i n o

PITUITARY APOPLEXY. CLINICAL AND IMAGING CONSIDERATIONS. M.A. de Miquel, J.M. Fernandez Real, J.J. Acebes, H.L. Espinet, J.L. Monfort, A. Muntane, ~ Soler, L.C. Pons. Hospital de Bellvitge, "Principes de EspaHa"

The A i m of this s t u d y is the e v a l u a t i o n of MRI u t i l i t y in the d i a g n o s i s of p i t u i t a r y microadenomas. T h e A u t h o r s h a v e e x a m i n e d 80 p a t i e n t s w i t h clinical manifestations and laboratory data s u g g e s t i n g the p r e s e n c e of a p i t u i t a r y lesion. P a t i e n t s u n d e r w e n t MRI s t u d y u s i n g m o s t l y T1 w e i g h t e d s e q u e n c e s (SE, G r a d i e n t Echo, IR). In 30 cases the e x a m i n a t i o n was c o m p l e t e d b y p o s t - c o n t r a s t M R scan w i t h p a r a m a g n e t i c c o n t r a s t medium. In 63 p a t i e n t s (79% of cases) a m i c r o a d e n o m a was r e v e a l e d , as a s m a l l area of low s i g n a l intensity. In 25 of t h e s e c a s e s u n e n h a n c e d MRI was not s u f f i c i e n t for the d i a g n o s i s , a n d it was n e c e s s a r y the aid of GdD T P A w h i c h c o n f i r m e d the p r e s e n c e of the l e s i o n and d e f i n e d its limits a n d extent. Concluding, on b e h a l f of our e x p e r i e n c e and b y l i t e r a t u r e ' s data, MRI, e x p e c i a l l y w h e n p e r f o r m e d a f t e r a d m i n i s t r a t i o n of p a r a m a g n e t i c c o n t r a s t m e d i u m , shows h i g h s e n s i b i l i t y , s i m i l a r w i t h d y n a m i c CT's, for the d i a g n o s i s of p i t u i t a r y microadenomas.

Pituitary apoplexy (PA) is usually defined as a syndrome characterized by the sudden onset of headache, accompanied at times by nausea and vomiting, associated with acute visual impairmet and/or ophtalmoplegia. It is caused by compression of perisellar structures or meningeal irritation after infarction or hemorrhage within a pituitary tumour. We reviewed the clinical records and imaging findings for ii patients with proven PA seen at our institution. Some of these patients were initially misdiagnu~ed. Some presented a clinical picture identical to a subarachnoid hemorrhage (SAH) due to a ruptured aneurysm (clinical presentation of 15 patients with SAH and proven aneurysms were also reviewed for comaparison). Others were simply under evaluated at the first clinical visit. MR images are discussed. We conclude that the timing of presentation is one of the characteristic clinical features of PA, and in front of this clinical suspition MR should be the first imaging study.

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N E U R O R A D I O L O G I C E V A L U A T I O N OF C R A N I O P H A R Y N G I O M A S F.Di S a l l e , L . S i m o n e t t i , R . M o r r o n e , S . C i r i l l o , R . S p a ziante, E.de Divitiis, R. Elefante, F.Smaltino. U n i v e r s i t Y of Naples The Authors report t h e i r e x p e r i e n c e in the neuroradiologic study of c r a n i o p h a r y n g i o m a s and they evaluate CT and MRI d i a g n o s t i c efficacy; an evaluation of b i o m o l e c u l a r t u m o r c o m p o s i t i o n is also proposed. The c o m p a r i s o n b e t w e e n these i m a g i n g modalities is p e r f o r m e d in 30 p a t i e n t s on the basis of the e f f e c t i v e n e s s in d e t e c t i o n and identification of the tumor; the p o s s i b i l i t y of a complete t o p o g r a p h i c s t u d y of the s e l l a r r e g i o n is also c o n s i d e r e d t o g e t h e r w i t h the a d v a n t a g e s in the presurgical evaluation. CT d e n s i t y and M R signal features have b e e n studied; the m a g n e t i c c o n f i g u r a t i o n of the n e o p l a s m has been a n a l i z e d both "in vivo" and "in vitro": a d e d i c a t e d p r e p a r a t i v e - a n a l i t i c a l biochemical p r o c e d u r e has been s t a n d a r d i z e d and ext e n s i v e l y a p p l i e d to the study of the c o r r e l a t i o n b e t w e e n m o l e c u l a r c o m p o s i t i o n and r e l a x a t i o n parameters. T1 values show an e v i d e n t inverse corr e l a t i o n w i t h o n l y h a e m o g l o b i n - r e l a t e d molecules, while the other m o l e c u l e s e x h i b i t slight inverse or no correlation. Short T1 r e l a x a t i o n times p r e s e n t also a c o r r e l a t i o n w i t h t u m o r structure, b e i n g rather usual in the cystic form of craniopharyngiomas. A c c o r d i n g to A u t h o r s ' o p i n i o n an h a e m o r r a g i c event is s o m e w h a t c o m m o n in the biological h i s t o r y of c r a n i o p h a r y n g i o m a s , it is p r o b a b l y related to cyst formation and it is crucial in p r o d u c i n g T1 hyperintensity.

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CYSTIC INTRACRANIAL S C H W ~ 0 M A S C.J. Wallace, T.C. Fong Foothills Hospital, 1403 - 29th Street N.W., Calgary, Alberta, T2N 2T9 The typical CT or MR appearance of trigeminal schwannoma is of a solid uniform enhancement. Although cystic been described in 10% to 20% of acoustic and a slightly greater percentage of

acoustic or tumor with areas have schwannoeas

trigeminal

nerve tumors (due to fatty or cystic degeneration, formation of arachnoid cysts or adhesions around the tumor), a predominantly cystic schwannoma is

unusual. A cystic cerebellopont~ne ( C P ) angle mass suggests a differential diagnosis of arachnoid cyst, epidermoid, or possibly exophytic glioma or meningioma with cystic change; however, in view of the fact that at least 80% of CP angle masses are acoustic nerve tumors, this diagnosis should be strongly considered when a cystic or partially cystic lesion is seen here. We reviewed the charts of 38 patients admitted to our institution with the diagnosis of acoustic or trigeminal neuroma within the past eleven years. Nine cases in which the tumor was mostly or entirely cystic were found, an unexpectedly high figure (24%). Seven of these were acoustic nerve tumors and two trigemiual; of interest, both of the trigeminal nerve tumors in this series were predominantly cystic. Imaging findings, and features assisting in specific diagnosis, are

discussed.

166 FLOW MRI : APPLICATIONS IN ACOUSTIC NEURINOMAS D. KRAUSE ; J.L. DRAPE ; V. BOSSER ; D. MAITROT ; J. TONGIO UNIVERSITY HOSPITAL STRASBOURG HAUTEPIERRE / FRANCE -

Purpose : To demonstrate the value for surgeons of flow imaging (gradient echo) in the d i f f e r e n t i a t i o n of skull base venous structures and acoustic neurinomas. The usual TI and T2 sequences are not the most appropriate f o r vessels ; angio-MR gives l i t t l e information concerning solid structures, especially tumoral tissue. Materials and methods ." The work-up f o r 7 acoustic neurinomas arising in the cistern of the pontocerebellar angle comprised the following : TR 80 ; Flip angle go ° ; TE 14 - 16 msec (gradient echo : time of f l i g h t sequences) - Monoslice acquisition ; 5 - mm thickness ; 2 excitations Axial, f r o n t a l , and sagittal or sagittal-oblique sections. -

-

Results : In case of a retromastoidal or translabyrinthine approach, the neurosurgeon should be aware of the exact location of the jugular bulb (which may vary), with respect to the acoustic neurinoma. Combined flow imaging and Gadolinium enhancement provided information concerning the tumor and skull base venous structures. Conclusion : This method seems to be p a r t i c u l a r l y informative for surgeons faced with acoustic neurinomas. These sequences are primarily intended to replace preoperative angiography.

REGROWTH POTENTIAL OF A C O U S T I C NEUROMA FRAGMENTS REMAINING AFTER S U R G E R Y - A S S E S S M E N T BY MRI J. E.Gillespie, R.H.Lye~A. P a c e - B a l z a n ~ R . T . R a m s d e n* and J.M. Dutton~ Departments of N e u r o r a d l o l o g y , N e u r o s u r g e r y and Otolaryngologye Manchester Royal Infirmary,Manchester, U.K. Object-To investigate the r e g r o w t h potential of tiny acoustic neuroma fragments left behind on the facial nerve,brain stem or major vessels in an otherwise "complete" tumour removal. Method-14 patients underwent magnetic resonance imaging on a General Electric MR MAX scanner (0.5T) a mean of 70 months after surgery (range 6 months-12 years). Tl-weighted spin-echo sequences (SE 600/25) were used before and after injection of gadolinium-DTPA. Results-7 patients had persisting tumour noted with m a x i m u m diameters between 5-25 mm. In 4 the tumour remnant was larger than that recorded at surgery. Tumour persistence was more likely if it was not cauterised at operation. C o n c l u s i o n s - l ) S m a l l tumour fragments may remain viable and regrow,though usually slowly.This may have implications for patient care especially when preservation of hearing is attempted. 2)Contrast enhanced MR is a sensitive means of detecting what is usually clinically silent regrowth.

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167 GADOLINIUM ENHANCEMENT OF THE CISTERNAL PORTION OF THE OCULOMOTOR NERVE: CLINICAL AND PATHOLOGICAL SIGNIFICANCE A.S.Marx~ P.Blake, M.Ross, S.Atlas, D.Brown Washington Hospital Center, Washington D.C., USA Gadolinium enhancement of the 2nd, 5th and 7th cranial nerves on MRI has recently been described in patients with respective cranial neuropothies. We report I0 patients with enhancement of the cisternol portion of the 3rd nerve. 50 control patients referred for pituitary microadenomas were also studied with coronal pre- and post-Gadolinium Tl-weighted images. None of the 50 controls demonstrated enhancement of the 5th nerve. The patients underlying diagnoses were viral meningitis (1 patient), leukemia (1 patient), lymphoma (3 patients), neurofibromatosis (2 patients), Tolosa-Hunt (1 patient), migraine (1 patient)~ inflammatory polyneuropathy in an HIV positive patient (1 patient). One other patient with lymphoma was HIV positive. Enhancement was bilateral in 5 patients. Six patients Six patients had 3rd nerve palsies but 4 patients were asymptomatic, 2 of them with neurofibromatosis. Enhancement of the cisternal segment of the 3rd nerve is always abnormal reflecting un underlying inflammatory or neoplastic process. This finding may not be associated with a 3rd nerve palsy.

169 MAGNETIC RESONANCE IMAGING OF THE C E N T R A L NERVOUS SYSTEM IN CHILDREN - INDICATIONS AND USEFULNESS IC-/~. Thuomas, K. Bergstr0m, G. Ahlsten, M. Dalai and K. Sj6rs Departments of Diagnostic Radiology and Paediatrics, University Hospital, Uppsala, Sweden Five years' experience with magnetic resonance imaging (MRI) of the central nervous system in children is described. Material and Method. M R / w a s carried out in 221 children of ages 015 years. Of these, the examination was performed on the brain in 142 children, on the spinal region in 35 and in both regions in 44. The clinical usefulness of MRI was evaluated from the medical records, and comparison was also made with computed tomography (CT) in this respect. Results. MRI showed pathological conditions in 143 of the children and normal conditions in 78. In 14 % a previously unknown diagnosis was made and in 23 % MR/provided information of clinical value. The examination was of special clinical usefulness in the demonstration of brain tumours and in visualizing lesions affecting the spinal cord. In comparison with CT, MRI gave information of greater clinical value in about half of the children. Conslusion. MR/implies a great advance in the diagnosis of diseases of the central nervous system in children.

168 C O N T R I B U T I O N OF 3 D I M E N S I O N A L I M A G I N G T O T H E E X A M I N A T I O N OF S K U L L B A S E T U M O R S

C. Louail, M. Raynaud, D. Gense deBeanfort, J.F. Gr~selle, J.M. Caill6 Service de Neuroradiologie. CHR. 33076 BORDEAUXc&lex (France)

The purpose of the present study was to evaluate a new technique, 3 dimensional imaging. Examinations were performed on 30 patients with skull base tumors, using a Magnetom Siemens 1.5 Tesla. In every case, the 3 dimensional sequence after injection of Gadolinium was compared with a spin-echo Tl-weighted reference sequence The authors discuss the contribution of the 3 dimensional sequence in comparison with classical Tl-weighted sequences. They analyse the contribution of this technique to the diagnosis of extra-axial lesions, its anatomical definition, its interest in the assessment of the extension of the lesions, and, t'mally, the total duration of the examination. Three dimensional imaging is an interesting technique because : - it is as sensible as spin echo sequences in the positive diagnosis of extra-axial tumors when used together with the injection of Gadolinium. - the assessment of the extension of the lesions is more precise than with spin-echo sequences because 3 D imaging can obtain thin sections in every plane of space. - it represents a considerable gain of time. Three dimensional imaging with injection of gadolinium appears to be a very promising technique in the exploration of skull base tumors, allowing a precise, reliable and fast diagnosis.

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Concurrent Scientific Session (WFITN): Aneurysms Moderators: V. Scheglov, Kiev, USSR and A. Molyneux, London, United Kingdom 08.30 a m - 10.00 am

Scientific Papers 1 7 0 -1 8 0

10.00 a m - 10.25 am

Coffee Break

a

08.30 am-lO.OO am Scientific Papers 170-180 170 Laser activated detachable coil device G.K. Geremia, M. Haklin, R. McCarthy, D.A. Charletta, Chicago, USA 171 Characteristics of platinum coils in canine carotid aneurysms V.B. Graves, C.M. Strother, A.H. Rappe, Q. Guiliermo, E Vifiuela, Madison, USA 172 Experimental study of aneurysm hemodynamics in a canine model C.M. Strother, V.B. Graves, Madison, USA 173 Experimental comparison between homologous fibrin, hyroxyaethyl-metacrylat (HEMA) and contrast dye for permanent solidification of different detachable balloons G. Bavinzski, B, Richling, W. Saringer, Vienna, Austria 174 Hema polymer and latex balloons: Bench and animal studies E J. Ives, H.T. ApSimon, A. Bartlett, D. Hartley, Perth, Australia 175 Wire-directed detachable balloon: Clinical applications K. Makita, S. Furui, K. Tsuchiya, T. Irie, T. Yamauchi, K. Takeshita, R. Katoh, Saitama, Japan

176 Histopathological study of balloon embolization: Silicone vs. latex S. Miyachi, M. Negoro, T. Handa, K. Terashima, H. Keino, K. Sugita, Nagoya, Japan 177 Cerebral angioplasty following aneurysmal subarachnoid hemorrhage L. E Alexander, Y.N. Zubkov, G. I3. Benashvili, Leningrad, USSR 178 Percutaneous transluminal angioplasty for vasospasmsuperselective intra-arterial infusion of papaverine Y. Kaku, Y. Yonekawa, T. Tsukahara, K. Kazekawa, Osaka, Japan 179 Arterial rupture during "distal" vasospasm angioplasty M. E Brothers, L.W. Hedlund, A.H. Friedman, Durham, USA 180 Balloon angioplasty for vasospasm after SAH experimental study and clinical experiences Y. Fujii, A. Takahashi, T. Yoshimoto, N. Boku, M. Ezura, K. Mizoi, Sendai, Japan

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170 L A S E R A C T I V A T E D DETACHABLE COIL D E V I C E G.K. Geremia, M. Haklin, R. McCarthy, Charletta

CHARACTERISTICS

D.A.

PURPOSE: We will d e m o n s t r a t e a w o r k a b l e m o d e l of a laser a c t i v a t e d d e t a c h a b l e coil d e v i c e for e m b o l i z a t i o n Of aneurysms. MATERIALS AND METHODS: Experimental a n e u r y s m s created in m o n g r e l dogs are the m o d e l s u s e d for embolization. The d e v i c e c o n s i s t s of an e m b o l i c coil w h i c h is a f f i x e d to the distal end of a laser probe. This d e v i c e is u n i q u e in that the coil can be r e p o s i t i o n e d or w i t h d r a w n even after the coil has e x t e n d e d b e y o n d the distal tip of the catheter. Thus, the o p e r a t o r has total c o n t r o l over the p o s i t i o n i n g and r e p o s i t i o n i n g of the coil. Once the coil is o p t i m a l l y placed, a c t i v a t i o n of the laser d e t a c h e s and d e p o s i t s the coil w i t h i n the aneurysm. A m o d i f i c a t i o n of the initial p r o t o t y p e d e v i c e has b e e n made. The current d e v i c e h a s b e e n m i n i f i e d so that it will fit into any c a t h e t e r w h o s e inner d i a m e t e r is at least 0.018". RESULTS: We h a v e s u c c e s s f u l l y e m b o l i z e d 9 of i0 aneurysms thus far w i t h this device. H i s t o p a t h o l o g i c examination of t h e s e a n e u r y s m s post embolization reveals reactive f i b r o b l a s t i c changes and fibrosis. CONCLUSION: We have d e v e l o p e d a w o r k a b l e l a s e r - c o i l d e v i c e p r o t o t y p e w h i c h is e f f e c t i v e in the e m b o l i z a t i o n of e x p e r i m e n t a l l y c r e a t e d aneurysms.

OF PLATINUM COILS IN CANINE CAROTID ANEUEYSMS

VB GRAVES, CM STROTHER, AH RAPPE, Q GUILLERMO, F VINUELA UNIVERSITY OF WISCONSIN, MADISON, WI USA UCLA MEDICAL CENTER, LOS ANGELES, CA USA Thirty-four aneurysms (24 lateral, 6 bifurcation, 4 terminal), 13 treated with Guglielmi coils (GDC), 16 curved coils with silk fibers (CSF) and 5 curved coils without fibers (CNF). Stability, compaction and thrombogenicity was evaluated. CNF coils placed in 5 lateral aneurysms produced average reduction of 16%, were unstable with migration in 4/5, dome (I) and parent artery (3). No parent artery occlusion. CSF coils placed in 16 aneurysms (14 lateral, 2 bifurcation) produced average reduction of 61%, 6/16 completely thrombosed. CSF coils were more stable with migration in 5/16, dome (2) and parent artery (3). Compaction occurred in 8/16. Complete parent artery occlusion 3/16, partial occlusion 2/16 and transient thrombus 5/16. GDC coils placed in 13 aneurysms (5 lateral, 4 bifurcation, 4 terminal) produced average reduction in size of 95% with 4/13 completely thrombosed. They were stable with migration in 4/13, dome (2) and parent artery (2). They did not migrate entirely out of the aneurysm as did CNF and CSF coils. Compaction occurred in 11/13. No parent artery occlusions, partial parent artery occlusion 1/13, transient thrombus 6/13. Silk fibers increased stability and thrombogenieity but increased parent artery thrembus and occlusion. Malleability and increased length of GDC coils allowed a larger amount of coil to be placed in the aneurysm increasing stability and thrombogenieity. Compaction of the GDC Coil was a limiting factor in achieving complete thrombosis. Transient thrombus in parent artery represents a potential complication.

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E X P E R I M E N T A L STUDY OF A N E U R Y S M H E M O D Y N A M I C S IN A CANINE MODEL CM Strother, V B G r a v e s U n i v e r s i t y of Wisconsin, Madison, WI U S A

EXPERIMENTAL COMPARISON BETWEEN HOMOLOGOUS FIBRIN, H Y D R O X Y A E T H Y L - M E T A C R Y L A T (HEMA) A N D C O N T R A S T DYE FOR P E R M A N E N T S O L I D I F I C A T I O N OF D I F F E R E N T DETACHABLE B A L L O O N S G. Bavinzski, B. Richling, W. S a r i n g e r D e p a r t m e n t of Neurosurgery, U n i v e r s i t y of V i e n n a Medical School

C u r r e n t e v i d e n c e favors the n o t i o n t h a t i n t r a c r a n i a l s a c c u l a r aneurysms occur, e n l a r g e and r u p t u r e b e c a u s e of h e m o d y n a m i c forces. G l a s s m o d e l experiments, numerical c a l c u l a t i o n s and c o m p u t e r s i m u l a t i o n s h a v e b e e n u s e d to p r e d i c t the h e m o d y n a m i c f e a t u r e s of lateral, b i f u r c a t i o n and t e r m i n a l t y p e aneurysms. U s i n g a c a n i n e model we h a v e s t u d i e d the flow c h a r a c t e r i s t i c s of t h e s e t h r e e t y p e s of a n e u r y s m s w i t h h i g h speed v i d e o fluoroscopy, c o l o r D o p p l e r and m a g n e t i c r e s o n a n c e angiography. The inflow to lateral a n e u r y s m s occurs at the d o w n s t r e a m e x t e n t of the o s t i u m w h i l e o u t f l o w is seen from the u p s t r e a m p o r t i o n of the ostium. A central v o r t e x of s t a g n a n t flow is a p r o m i n e n t feature of lateral aneurysms. The site of inflow and o u t f l o w in b i f u r c a t i o n or t e r m i n a l a n e u r y s m s d e p e n d s u p o n the size and b r a n c h i n g g e o m e t r y of the a d j a c e n t a r t e r i a l branches. Circulation within these types of a n e u r y s m s is r a p i d w i t h no t e n d e n c y for v o r t e x formation. F l o w w i t h i n aneurysms is s e l d o m if ever t r u l y t u r b u l e n t but is r e g u l a r and h i g h l y predictable. A m o r e c o m p l e t e u n d e r s t a n d i n g of t h e s e h e m o d y n a m i c features is useful in h e l p i n g to o p t i m i z e the e n d o v a s c u l a r t r e a t m e n t of intracranial aneurysms. In t h i s presentation, the d e t a i l s of these studies will be d e m o n s t r a t e d u s i n g v i d e o r e c o r d i n g s of angiographic, u l t r a s o u n d and M R examinations.

F i l l i n g of d e t a c h a b l e balloons w i t h p e r m a nent s o l i d i f y i n g agents p r i o r to detachment is a well i n t r o d u c e d technique in e n d o v a s c u lar b a l l o o n therapy. Hydroxy~ethylmetacrylat (HEMA) polimerizes and solidifies within 60 to 90 minutes after beeing cathalyzed. This s u b s t a n c e is commonly u s e d as p e r m a n e n t embolic ~agent in detachable balloons. Recent p u b l i c a t i o n s and own experiences p o i n t e d out d i s a d v a n t a g e s in the use of this substance like t o x i c i t y if brought in contact w i t h brain' tissue and aggressive interaction w i t h the b a l l o o n material. Homologous controlled-viscosity fibrin has b e e n p u b l i s h e d and used for p r e o p e r a t i v e embolization of v a s c u l a r i z e d tumors. This nontoxic radiopaque h u m a n substance p o l i m e r i zes from two components, the speed of s e t t i n g d e p e n d i n g on the amount of thrombin. Low thrombin content allows the use of this agent for p e r m a n e n t s o l i d i f i c a t i o n of detachable balloons. A choice of different s i l i c o n and latex balloons has been filled e x p e r i m e n t a l l y w i t h contrast dye, HEMA and homologous fibrin s i m u l a t i n g e n d o v a s c u l a r conditions to control the b e h a v i o u r of the d i f f e r e n t solidifying agents over different periods of time.

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HEMA POLYMERAND LATEX BALLOONS: BENCHAND ANIMAL STUDIES Dr FJ Ives, Dr HT ApSimon, A B a r t l e t t , D Hartley Radiology Department, Royal Perth Hospital, Perth, Western Australia

WIRE--DIRECTED DETACHABLE BALLOON:CLINICAL APPLICATIONS K. Makita, S. Furui, K. Tsuchiya, T. Irie, T. Yamauchi, K. Takeshita, and R. Katoh Department of Radiology, National Defense Medical College, Saitama, Japan

Despite recent concerns about early rupture of latex balloons with HEMApolymer, l i t t l e has been reported on the risk and nature of this problem. We have assessed degeneration and rupture of HEMAf i l l e d balloons over a period of up to 4 weeks. The balloons were teste~ in 3 different environments: physiologic saline at 37 , dog peritoneal cavity, and within the vascular system in our previously described fistula/aneurysm model (Neuroradiology 1991, 33(supplement): 537-538). Two different types of latex rubber, and HEMAsupplied by 2 different manufacturers (containing d i f f e r e n t quantity and type of i n h i b i t e r ) were used. Observations were also made on balloons f i l l e d with other components of the HEMA polymer system. The d i f f e r e n t latex rubber preparations had a profound had a profound effect on the degradation and rupture rate. In the preferable form of rubber (Revultex SV) there was no s i g n i f i c a n t degradation with either laboratory or opthalmic grade HEMA. The only other factor found to degrade the latex was 3% hydrogen peroxide. We have previously found u l t r a v i o l e t l i g h t w i l l degrade latex as well. We experienced some d i f f i c u l t y with the r e l i a b i l i t y of commercial preparations of HEMA polymer and have developed our own mixture of opaque polymer, which w i l l be described.

176 HISTOPATHOLOGICAL STUDY OF BALLOON ENBOLIZATION SILICONE VS. LATEX S. Miyachi, M. Negoro, T. Handa, K. Terashima, H. Keino, K. S u g l t a Department of N e u r o s u r g e r y and P e r i n a t o l o g y Nagoya U n i v e r s i t y School of Medicine B i l a t e r a l , symmetrical, e x p e r i m e n t a l a n e u r y s m s were p r o d u c e d with a n a s t o m o s e d v e i n f l a p in t h e c a r o t i d a r t e r i e s of 24 mo ngr el dogs. Aneurysms were o c c l u d e d with l a t e x o r s i l i c o n e b a l l o o n s on each s i d e and observed angiographically from two weeks t o two months. A h i s t o p a t h o l o g i c a l study was performed s u b s e q u e n t l y u s i n g l i g h t and s c a n n i n g e l e c t r o n microscopy. R u p t u r e f o l l o w i n g b a l l o o n e m b o l i z a t i o n o c c u r r e d in f i v e aneurysms, a l l of which were i n c o m p l e t e l y o c c l u d e d by a s i l i c o n e b a l l o o n . On s u b s e q u e n t a n g i o g r a m f o u r s i l i c o n e b a l l o o n s and one l a t e x b a l l o o n were f o u n d t o h ave m i g r a t e d i n t o t h e aneurysm, r e s u l t i n g in a n e u r y s m a l e x p a n s i o n . P a r e n t a r t e r y o c c l u s i o n was more common with l a t e x b a l l o o n s t h a n s i l i c o n e b a l l o o n s . H i s t o p a t h o l o g i e a l l y r e s i d u a l f r e s h thrombi, l e s s p r o l i f e r a t i o n o f f i b r o b l a s t s within t h e a n e u r y s m a l c a v i t y and p o o r e n d o t h e l i a l i z a t i o n were p r e s e n t a r o u n d s i l i c o n e b a l l o o n . These r e s u l t s suggest that intraaneurysmal o r g a n i z a t i o n , as s e e n in t h e aneurysm o c c l u d e d by t h e silicone balloon, wilI delay because the balloon is not f i x e d w i t h i n t h e aneurysm, and t h a t such f r e e - f l o a t i n g and r o t a t i n g b a l l o o n e a u s e s r e p e a t e d aneurysm w a l l trauma, c o n t r i b u t i n g to s u b s e q u e n t e n i a r g e m e n t and r u p t u r e of t h e aneurysm. The s u p e r i o r a n t i - t h r o m b o g e n i e n a t u r e of s i l i c o n e may be r e s p o n s i b l e f o r t h e b i a s of such phenomena toward t h e s i l i c o n e b a l i o o n .

Purpose Detachable balloons are used for endovascular occlusion therapy mainly in interventional neuroradiology. The flow-directed method is used for the insertion of the balloons. We have developed a new silicone detachable balloon which can be advanced over a guidewire. The placement techniques and c l i n i c a l applications of o u r w i r e directed detachable balloons are reported. M a t e r i a l s and M e t h o d s W i r e - d i r e c t e d detachable balloons are made o f s i l i c o n e a nd h a v e two s e l f sealing valves. The proximal valve grips the catheter-tip a nd t h e d i s t a l valve allows a guidewire to pass through. The b a l l o o n is first advanced over the guidewire to the target. When the balloon is successfully located, the guidewire is withdrawn and the balloon is inflated and detached using the same method as for the conventional detachable balloon. T h i s new detachable balloon method was u s e d for a r t e r i a l redistribution for the infusion chemotherapy (n=lO) and the management of varicoceles (n=5) as i n i t i a l clinical applications. Results The balloons were successfully placed using the wire-directed method in the intended vessels in all cases. No complications resulted. Conclusion Our w i r e - d i r e c t e d detachable balloon i s e a s i l y and a c c u r a t e l y placed independently of blood flow. The a v a i l a b i l i t y of this new device will extend the clinical applications of detachable balloon techniques.

177 CEREBRAL ANGIOPLASTY FOLLOWINg K~EURYSMAL SHEggACHNOID HEMORRHAGE L.F. Alexander, M.D. 7.N. Zubkov, M.D. a,B. Benashvili, M.D.

A.L. PoJemov t{e~cosurgicalResearch Hospital Leningrad, USeR

Our neurosur~er~ service employ~ angioplasty ie the m~tlmodsl therapy o£ cerebral vasospasm following aneurysmal subarachnold hemorrhage. We report our results of treatment of 89 consecutive patients with radiographic and clinical confirmation of vasospasm. Constant monitoring and neurolelr~algesia were used. Latex balloon catheters were introduced via the common carotid urterg for anterior circulation spasm, and through the axillary urter~ for vertebro-b~silar pathology. 58% of patients underwent dilation prior to direct clipping; 18% were tr~ted pea%operatively. 8% of patients underwent si~itaneous angioplBsty and detachable helloon occlusion of eaeurysm. 53% of patients underwent dilation in a single vascu/ar tree, whereas 47% had bilateral carotid or carotid-hasilar angioplasty. 70% of patients were judged to have severe spasm; 77% of this was diffuse. The indication for angioplasty was increasir~ hemispheric d~sf~ctio~ with depressed level of c o s s c i ~ e s s in 66% of patients, and progressive hemipareals in 34%. 58% of patients were Hunt and }less grade III at the time of treatment; 27% were grades IV or V. Improvement of hemidsficits, or amelioration of decreased level of conscio~snessp or hath, was achieved iD 78% of patients. Autops~ material revealed r~o arterial d~mage fro~ dilation. We feel that angioplssty deserves a prominent place in the neurosurglcal treatment of vasospa~. Our protocol for the tinting and implementation of angiopleaty will he presented, as well illustrative angiograph~ and technique.

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PERCUTANEOUS TRANSLUMrNAL ANGIOPLASTY FOR VASOSPASM -SUPERSELECTIVE INTRA-ARTERIAL INFUSION OF PAPAVERINE-

ARTERIAL RUPTURE DURING "DISTAL" VASOSPASM ANGIOPLASTY MF Brothers, LW Hedlund, AH Friedman Duke University Medical Center, Durham, NC

Y.Kaku,Y.Yonekawa,T.Tsukahara,K.Kazekawa Department of Neurosurgery,National Cardiovascular Center, Osaka,Japan Introduction While percutaneous transluminal angioplasty(PTA) for vasospasm after subarachnoid hemorrhage has been performed in selected cases, the distal middle cerebral artery(MCA) or sharply angled vessel, such as the anterior cerebral artery(ACA), are usually inaccessible to the angioplasty balloon catheter. We report successful treatment of such peripheral spastic vessels with superselective intra-arterial infusion of papaverine hydrochrolide. Methods PTA was performed in two steps, as follows: the silicone balloon was used for dilation of the internal carotid artery and the proximal MCA, and a leak balloon or Tracker 18 catheter was then introduced into or just proximal to the distal MCA or the ACA, so that 6mg of 0.2% papaverine hydrochloride, 0.5mg of nicardipine could be superselectively infused through it. Result Seventeen

of 20 vascular territories were successfully dilated, and 5 of 7

patients showed improvement of neurological functions after PTA. There was no serious side effects due to infusion of papaverine. On follow up angiography, the dilated vessels exhibited continuous signs of recurrence of stenosis.

patency without

Conclusion Superselective intra-arterial infusion of papaverine may be an alternative form of treatment of symptomatic vasospasm after subarachnoid hemorrhage.

180 BALLOON ANGIOPLASTY FOR VASOSPASM AFTER SAH -EXPERIMENTALSTUDY AND CLINICAL EXPERIENCESY Fujii t, A Takahashi~, T Yoshimoto 2, N Boku ~, M Ezura1, K MizoP ~Div. of Intravascular Neurosurg., 3Dept. of Neurosurg., Kohnan Hospital, ~)iv. of Neurosurg., Institute of Brain Diseases, Tohoku University, Sendal, JAPAN The purpose of this paper are to present our experimental and clinical investigations on balloon angioplasty for vasospasm after subarachnoid hemorrhage (SAH). Using canine double hemorrhage model, angiographical, pathological and pharmacological influences of balloon angioplasty on basilar artery was studied. Angiograpically, angioplasty was most effective on the peak of vasospasm and dilatation effect was maintained several weeks after the procedure. Pathologically, denudation of endothelial cells, stretching of internal elastic lamina without disruption of muscle layer were observed immediately after the angioplasty. These influences were cleared within 4 weeks without any sclerotic changes such as intimal hyperplasia. In vitro pharmacological study of angioplasty on vasospastic segment showed significant reduction of vascular tension induced by vasoconstrictors. These results suggest that balloon angioplasty for vasospasm would be most effective on its peak and the mechanism of continuous dilatation may be slight functional vascular damage affecting muscle tension. In clinical situations, we have treated 26 cases of vasospasm. Most cases had been treated in the early stage of their symptoms. With continuous improvement on catheter system, it is now possible to dilate all areas of basal to cortical vasospastic segments. Clinical symptoms were improved in 70% of cases. Main factors influencing the outcome was the delay between the evolution of neurological deficits and angioplasty. Favorable clinical results were achieved in almost all cases who had been treated within 6 hours of their symptoms The role of angioplasty on the neurosurgical management of SAH patient will be discussed based on these experiences.

(A) T O d e s c r i b e a c a s e of f a t a l r u p t u r e of a n MCA cortical branch complicating vasospasm angioplasty; (B) p r e s e n t analysis of factors contributing to this event. Extending cerebral angioplasty to more distal symptomatic territories (A2, M 2 ) h a s p r e v i o u s l y been demonstrated to be successful using the prototype ITC balloon catheter device but control over balloon diameter is c r i t i c a l . A patient with post-SAH vasospasm severely symptomatic o n l y in a " d i s t a l " M C A t e r r i t o r y was referred for angioplasty. During inflation of the balloon in t h e i n v o l v e d M2 b r a n c h , arterial rupture occurred. We analyzed the technical factors contributing to this, particularly the pressure/volume characteristics of t h e b a l l o o n . 15 b a l l o o n s were tested. Minimal (20%) i n f l a t i o n of t h e u n r e s t r i c t e d balloon leads to abrupt pressure peak of about 3 5 0 m m Hg, w h i c h o n f u r t h e r inflation diminishes and levels off to about 280 mm Hg near full inflation. Restricting the inflation diameter in a 2 m m " v e s s e l " (9F c a t h e t e r lumen) resulted in s t e a d y i n c r e a s e in p r e s s u r e after the initial peak, reaching 6 0 0 m m H g at 6 0 % a n d 1 4 0 0 m m H g at 1 0 0 % i n f l a t i o n on average. "Distal" angioplasty requires extreme caution, a n d t h e u s e of i n f l a t i o n volume far less than the maximum 0.1cc. The "elongating" behavior of t h e b a l l o o n , when diameterrestricted, does not provide protection against arterial rupture, as d a n g e r o u s l y high pressures are generated early.

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Concurrent Scientific Session (ESNR): Spine and Spinal Cord Moderators: G. Ruggiero, Bologna, Italy and C. Manelfe, Toulouse, France 11.00 a m - 01.00 pm

Scientific Papers 18 i - 196

01.00 pm

Scientific Award ESNR Closing Remarks (J. P. Braun, President ESNR)

11.00 am-01.00 pm Scientific Papers 181-196 181 Comparative morphometry of the cord and spinal canal by magnetic resonance imaging (MRI) and postmyelographic computed tomography (PMCT) M. Warmuth-Metz, Th. Becket, E. Hofmann, B. Kapp, W~rzburg, Germany

189 Spinal nerve radiculitis: Gadolinium enhanced MR in the pre- and post-operative lumbosacral spine J.R. Jinkins, San Antonio, USA 190 MRI characterization of cervical spine injury (CSI) resulting from motor vehicle crashes (MVC)

182 MR CSF flow measurement and real-time digital subtraction technique in cystic spinal lesion A.K. Wakhloo, M. Schumacher, V. van Velthoven, J. Hennig, Freiburg, Germany

A.K. Anand, J. I, Barancik, H.C. Thode, C. E Kramer, C.T. Roque, Stony Brook, USA 191 Three dimensional imaging in the trauma of the dorsolumbar spine

183 The natural evolution of lumbar disk herniation as assessed by MR A. Bozzao, M. Gallucci, A. Cifani, I. Aprile, M. Masciocchi, A. Barile, M. Mastantuono, A. Splendiani, UAquila, Italy 184 Diagnostic possibilities of CT-discography M. Leonardi, G. Fabris, A. Lavaroni, E. Biasizzo, S. D'Agostini, B. Zanotti, Udine, Italy 185 Retroodontoid cystic "ghost" pseudotumors in cases of atlantoaxial instabilities ca~used by primary chronic polyarthritis J. Ken6z, L. Tur6czy, P. Barsi, R. Veres, Budapest, Hungary 186 Ciinic-radiologic evaluation in OPLL M. Rovira, A. Rovira, J.M. Mercader, G. Garcia Verde, M. Bertomeu, M. Rovira, Barcelona, Spain 187 Extradural and intramedullary tuberculous granulomas - MR specificity and signal characteristics - evaluation

of 30 patients S.B. Desai, V. C. Shah, O. J. Tavri, P. Rao, A. Kohli, Bombay, India 188 Tuberculous osteitis without discitis - MR evaluation V.C. Shal'/, S.B. Desai, O. J. Tavri, P. gao, A. Kohli, Bombay, India

C. Louail, R. Tran, A. Bouamama, D. Gense de Beaufort, J.M. Vital, J.M. Calll6, Bordeaux, France t92

MRI findings of aortic pathology in patients with clinical suspicion of spinal disease E.M. Larsson, M. Heijling, S. Holt,s, Lund, Sweden

193 The variable presentations of craniocervical and cervical dural arteriovenous malformations of the spine K.G. terBrugge, R.A. Willinsky, W. Montanera, P. Lasjaunias, Toronto, Canada 194 Serial enhanced MR scans in multiple sclerosis of the spinal cord: Clinical importance M.A. Mikhael, Evanston, USA 195 MRI and neurological complications of adult T-cell leukemia

J.L. Dumas, J.M. Visy, P. Brugi6res, E Lhote, P. Vassel, J. Amouroux, D. Goldlust, Limoges, France 196 MRI of primary and metastatic bony lesions of the spine G.C. Dooms, M.A. Labaisse, J. Malghem, B. Maldague, Brussels, Belgium

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COMPARATIVE MORPHOMETRY OF THE CORD AND SPINAL CANAL BY MAGNETIC RESONANCE IMAGING (MRI) AND POSTMYELOGRAPHIC COMPUTED TOMOGRAPHY (PMCT)

MR CSF FLOW MEASUREMENT AND REAL-TIME DIGITAL SUBTRACTION T E C H N I Q U E IN C Y S ' n C S P I N A L L E S I O N

M. Warmuth-Metz, Th. Becker, E. Hofmann, B . Kapp Dept. of Neuroradiology, University of WOrzburg

AK Wakbloot.M Schumacherl,Vvan Veithoven2,JHennig3

Summary: MRI i s considered to be the method of choice in the assessment of spinal pathology. Artefacts by truncation and unpredictable phase shifts due to cerebrospinal fluid (CSF) flow can result in blurred demarcation of the cord and spinal structures. Since CSF-flow varies in different sections of the spinal canal and in addition stenoses cause CSF-flow ecceleretion, MRI may provide erroneous information of spinal canal width and intraspinsl structures. By means of dual examination by PMCTs and MRIs 187 spinal segments in 53 unselected patients were analyzed. Segittal diameters of spinal canal, cord and ventral and dorsal CSF-spsce were measured and compared in 91 cervical, 29 thoracic and 67 lumbar segments. The impact of MRI-parameters, segmental location and coils was analyzed. Discrepancies in anatomic measures could be eliminated by selection of MRI-coils in patients without spinal canal stenosis. Optimization of MRI technical parameters failed to resolve missmatch in cervical anatomic measures particularly in the presence of severe stenosis.

183 THE N A T U R A L E V O L U T I O N OF LUMBAR ~ DISK HERNIATION AS ASSESSED BY MR. A.Bozzao, M. Gallucci, A. Cifani, I. Aprile, C. Masciocchi, A. Barile, M. Mastantuono, A. Splendiani Dept. of Radiology, University of L'Aquila Italy The natural history of lumbar disk herniation treated nonoperatively has been p r e v i o u s l y studied, both from a clinical and a radiological point of view. Aim of our study has been to correlate disk herniation evolution to the severity of the neurological symptoms and signs it produces and to formulate some pathogenetic hypothesis. Therefore, we performed a follow-up study on a large number of patients, in order to make a statistical analysis. In the past three years in our Institution, 1116 MR examinations of the lumbar spine have been performed. In 286 patients the diagnosis of disk h e r n i a t i o n was made. 86 accepted to undergo a MR follow-up, 6-15 months° after the first exam. A d e d i c a t e d software has m a d e it possible to p e r f o r m a volumetric e v a l u a t i o n of disk e x t r u s i o n on sagittal and axial planes. On the basis of the volumetric changes of disk herniation the patients were c l a s s i f i e d in four groups. The clinical e v a l u a t i o n was performed using a method stated by P e a r c e and Moll. Our data showed a thi~ht correlation between m o r p h o l o g i c a l and clinical findings, an high incidence of r e g r e s s i o n of herniated material (63%) and a low incidence of p r o g r e s s i o n (8%).

";Sectionof Neuromdiology,2Deparknentof Neurosurgeryand 3Departmentof Radiology. University of Freiburg Exact preoperative~ocaHzat~n of spinet cystic lesions is s prerequistefor su~cessM surge~. If an entireexcision of an extensivecyst is not feasiNe,an existingcommunicationwith the subarachnoid space should be obl~leretedto avoid CSF leak and recorranee. In the 8 patients on whom MR imaging, CT mydography and mye~ographywere performed, the precise location of the communication between the cyst end suberachndid space could not be identified, Heav~ T2-weighted image (RARE, Rapid Acquisit'~ with R S I ~ Enhancement)and MR CSF flow measurement (DOPE, Double Phase Encoding) could determine the complete expansion of the lesion and indicate an possible existing commuff~tion of the cyst with the suberachnoid space respectively. However, the precise location of the communication was not visible. Hence in 7 patients s puncture of the cyst was carded out with a 22-gauge spinal needle. 810 ml of non-ionic contrast agent were injected under real4ime digital fluoroscopy at a rate of 12.5 pictures/see. The pattem of CSF-flow and the precise location Of the communication were visible, a possible valvelike mechanism could be excluded. MR CSF flow measurement seems to be a promising non.invasive diagnostic procedure to detect a possible existing communication between a spinal cystic lesion and the aubarechnoid space. However, digital subtraction technique, being a dynamic investigation, is the only diagnostic method to provide the essential anatomical and functional details for surgery,

184 DIAGNOSTIC POSSIBILITIES OF CT-DISCOGRAPHY M. Leonardi, G. Fabris, A. Lavaroni, E. Biasizzo S. D'Agostinl, B. Zanotti Servisio di Neuroradiologia, Ospedale Civile; Udine, Italy Authors expose their diagnostic experience with CTDiscography applied to about I00 cases of difficult problems of differential diagnosis, particularly focusing the postoperative recurrence of sciatica in itLmbar disc hernia. Discography is performed, in the authors experience, with posterolateral extradural approach: 1.0 ml of contrast medium (Jopamiro 300) is injected. CT examination is performed about two hours later. Five or six thin slices are usally taken at the center of the disc to avoid artifacts due to partial volume effect. CT-Discography findings: Normal CT-Discography: rounded centrodiscal image. - Degeneration: the entire disc is irregularly specified by contrast medium. - Anulography: contrast specifies the fibers of the anulus. - Hernia: direct visualization of the herniated nucleus pulposus, with evidence of the hernial pathway. Postoperative scar tissue: contrast medium does not diffuse in the epidural space. CT-Discography allows extremely precise anatomo-neuroradiological investigation of the disc, demonstrating disc pathologies difficult to be recognised by plain CT scans or even (sometimes) by MRI. CT-Discography is, in fact, the only exam that allows direct visualization of the nucleus pulposus, wether intradiscal or herniated, differentiating it from the anulus and any epidural scarring. -

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185

186

RETROODONTOID CYSTIC "GHOST" PSEUDOTUMORS IN CASES OF ATLANTOAXlAL INSTABILITIES CAUSED BY PRIMARY CHRONIC POLYARTHRITIS J. KENI=Z~, L TUROCZY2, P. BARSl~, R. VERES 2 Semmelweis Medical University, Dept. of Neurology, Budapest, Hungary National Institute of Traumatology, Dept. of Neurosurgery, Budapest, Hungary

CLINIC-RADIOLOGIC EVALUATION IN OPLL M. Rovira C., A. Rovira*, J.M.Mercader, M.Bertomeu, M.Rovira

In the last ten years, the authors investigated 24 cases of serious atlantoaxial instabilities caused by pdmary chronic potyarthritis, by means of functional analogous tomography, functional myelotomography, CT and CT assisted myelography, and recently in few cases by MR, too. The instability appears because of progressive osteoligamental damage, and leads to progressive neurological deficit. It is well-known pattern, that the jeopardised ligaments allow abnormal forward movement of the atlantic ring, thus its posterior arch compresses the spinal cord. In some cases, retroflexion reduces the dislocation, but does not reduce the naurologic signs and pain. On detailed functional myelographies and CT studies of ligamental structures, we found, that cystic degeneration of transverse ligament, damage of the attantoodontoid and ligamento-odontoid joints produces a certain "ghost" pseudotumor behind the odontoid, maintaining the cordcompression even in retroflexion. In these cases, simple reduction and stabilization will not be helpful. The details of these cystic pseudotumors, and their pathomechanism and behaviour on functional CT studies will be dealt with.

187 EXTFCADL~G~_ ~@} I ~ Z I J ~ R Y MR E~ECIFICITY D~x~)~I~4D4_

G.Garcia Verde

CRC, *Unldad de Resonancia MagnStica We have made a retrospective

study of i0 patients affec-

ted by ossification of the posterior longitudinal ligament (OPLL) diagnosed by CT and/or MR. In spite of the severe stenosis of the spinal canal, in most of the cases there were no signs of cervical mielopathy;

if any, they were

well tolerated. On the contrary, acute or subacute lesions of the cervical medulla,

suchs as traumatisms,

herniated

discs, etc, have shown severe myelopathlc signs, in spite of the scarce stenosis of the canal. The intramedullar pathologic alteration occasioned by the direct compression of the medulla is less frequent in the medium and chronic compressions,

as it happens in the

OPLL, than in the acute or subacute

compressions.

188 ~,ZI]LOUS ~/EEFE~ISTICS

~,ILLOi~- EVBLUATION

EE E~ PATIE~rS.

BISCITIS -- NR E~ALL~TION

V.C. Sk~h, *S.B. Besai, O.J. Tavri, P. Rao, A. K ~ l i Breach Candy Hospital & Re=_earch Centre, ~bay, India

*S.B. Desai, V.C. Shah, 0.~. T~/ri, P. Rao: A. Kohli Breach C~no~y Hospital & Research Cer,tre, Bombay, India *Jaslok Hospital & Research Centre, ~ , b a y ,

TUEE~EUL03S E67EITIS W I ~ F F

India

2i patients wit]7 extradural tL~ber~ul~=-, ard 9 patients with intrame~Jllary t u b e r c u l c ~ s ~ r e mtudied with MRI. All patients ~-re studied cr, 1.0 TESLA Siemens M A G ~ T O M ~-upercond~ting magnet. Both TI and T2 ~ i b h t e d i~Tges were obtained in different ple~es. In fe~, GadoliniL~ enhanced MRIs were obtained. E p i d ~ a l gr~nulomas were as~-ociated with or without tuberculous spcrdylitis. Intrmmedul lary tuherculcmas e=~_~ntial ly pre~,t~--d as cord tumors without ~ny t:r_~y involvement. Epidural tubercul~u~ gra~.~lo~_~ ~ d s~hort T1 ~ d long T2 and appeared hyper intense cc,~pared to muscle intensity c~ TI weighted images and ~ore hyper intense o n T2 ~ i g h t e d images. Intra~dullary tu~erculomas had inter~rediate TI and skirt T2 ar~ appeared imo to h-ypo intenae on T1 ~ighted images ~ extremely b/pc intense o n T2 ~ighted i~_~. T~e pat#ological correlation of t~t~ differer~e in signal intensity pattern beb~4-~r,, epidermal and intra~-dul imry tub~rculcmls granulm~is mrd the specificity of ~ I in these le~i~nm is diecu~-ed.

*Jaslc~ Hospital & Re~_ee~h Centre. Bm~bay,

Italia

Fourteen patient=~&th Tuberculri~s Osteitis eer~ studied with MRI. AII patients were stLdied on 1.0 TESLA Siemens ~,GNETOM supercor, ductir~ ~ g r e t . Both TI ard T2 weighted images ~ r e obtained in all. In few, Gadolini~r~n~r, ced ~ I s were d~ne. Gadolinium ,~s injected in a dc~_e of O.i~,.no!/kg of body ~ i g h t . On Ti e~ight~d immQes, tkere was focal to diffuse b/Fo intensity seen in involved vertebra/vertebrae. ]]-ere was break in the aqteri_nr cortical c~tline of tke vertebrae. Tfe lesions appeared b/per inten=_e or, T2 e~ighted images. T#e interv~nirrg di~_cs were e~-sentially r~rmal. TYe involvement of tkm spine varied frc~, ore vertebra to fo_~ verteb-ae. The baselire plain re~ic~rapf.~ were ~r~s~rkable. Tke le=~icr,s disappeared cr, ar~ti-Tuberculous tkerap! in 12 patients. Two peti~ts [u-rd~ t i~rgery for decc~T~r~ion of associated Grarm~le~. The -soaring of intervening di~_cs is ~-obably the re!~It of m u ~ - - l i ~ e n t o l s spread of the infection and defie~ the tJ-eory of ccntig~rils spread. Tke poe~ible etiology of [~teitis spmrir~ the discs is analy~_ed ard dimcus~ed.

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189 S P I N A L NERVE RADICULITIS: GADOLINIUM ENHANCED PRE- AND POST-OPERATIVE LUMBOSACRAL SPINE

190 MR IN THE

J.R. JINKINS The University of Texas H.S.C. at San Antonio PURPOSE: To prospectively evaluate the pre- and post-operative lumbar spine by gadolinium enchanced MR for evidence of clinically correlative abnormal enhancement° MATERIALS AND METHODS: 200 subjects with lu~nbosacral pain syndromes were prospectively evaluated preoperatively with MR (Group I). A retrospective study of 100 patients with recurrent symptomatology following lumbar disk surgery were also studied (Group II). In addition, i0 asymptomatic subjects were examined after successful disk surgery (Group IIl). T1 weighted images were obtained in the sagittal and axial planes before and after the administration of IV gadolinium (0.i r~nole/kg). Evidence was sought for intrathecal enhancement of lumbosacral nerve root(s). RESULTS: I0 individuals in Group I revealed abnormal radicular enhancement (5%), and 15 subjects in Group II demonstrated intrathecal nerve root enhancement (15%). The 10 asymptomatic patients in Group III all manifested degrees of post-operative epidural scarring on MR, but no abnormal neural enhancement. CONCLUSION: The presence of radicular enhancement following administration of IV gadolinium on MR imaging in symptomatic individnals, and its absence in asymptomatic subjects, indicates that neural enhancement serves as a marker for active inflan~aatory radiculitis, The higher incidence of abnormal enhancement postoperatively (15%), compared with the pre-operative group (5%), suggests that such pathology may be partially related to the surgical procedure. It is postulated that the phenomenon of radieulitis is causally related to some of the symptoms associated with some lumbosacral pain syndromes.

191 THREE DIMENSIONAL IMAGING IN THE TRAUMA OF THE DORSOLUMBAR SPINE

C. Louail, R. Tran, A. Bouamama D. Gense deBeaufort, J.M. Vital, J.M. Caill6 Service de Neuroradiologie. CHR. 33076 BORDEAUXC6dex (France)

The authors evaluated the contributions of three dimensional reconstructions with CT-scan in the traumatic pathology of the dorsolumbar region. 3 D imaging was performed routinely in the pretreatment evaluation, following a standard CT-scan examination, using a Somatom DRH Siemens. In 25 cases, the results of 3 D imaging performed before treatment were compared to the surgical f'mdings. 3 D reconstruction can determine the mechanism of fracture whether it is by compression, flexion-distraction translation of pure distraction, allowing a better surgical approach. However, the native CT-scan slice remain indispensable ot visualize the small details of the fracture, which are not observable with the 3 D reconstruction because of smoothing of the image. The authors emphosize the particular interest of this technique in the exploration of posterior arch lesions and complex displacements. The scanner with 3 D reconstruction appears as an useful examination in the pretreatment evaluation of traumatisms of the dorsolumbar spine, because it determines the mechanism of the fracture.

Mill CHARACTERIZATION OF CERVICAL SPINE INJURY (CSl) RESULTING FROM MOTOR VEHICLE CRASHES (MVC) AK Anand 9 Jl Barancik~ HC Thode, CF Kramer~ CT Roque Brookhaven National Laboratory; Long Island Diagnostic Imaging; State University of New York, Stony Brook and Albany This investigation presents MRI findings of a clinical-epidemiological-engineering study to characterize lower severity level CSI. It was undertaken because CSI incidence rates from MVC doubled after promulgation of the first U.S. safety belt use law. A 50% radiology clinic sample of MVC-caused CSI-MRI cases (N=157) was analyzed by type, location, and anatomic severity using ICD-9CM and AIS-85 codes. Cases were classified into "acute" (36%), "chronic" (9%) and "negative/normal" (55%) categories. Mill scans revealed anatomic damage r especially soft tissue lesions~ not discernable by other imaging techniques. Nearly half of all scans were conducted three months after the MVC9 suggesting a need to explore implications of elapsed time from MVC to MRI. Nearly 50% of "acute" cases had 2+ lesions identified by MRI and 75% had lesions between C5-C6. For "acute" cases with disc herniation or dislocation, CSI location differed by gender (p ~.05): males were injured lower on the spine (C6-C7)~ females were injured higher (C4-C6). The findings suggest a need to expand typical scanning field perimeters to fully characterize soft tissue lesions. The ineidence~ severity~ and cost of CSI have been significantly underestimated. Overall study findings suggest that CSI may be amenable to cost-effectlve mitigatlon.

192 MRI FINDINGS OF AORTIC PATHOLOGY IN PATIENTS WITH CLINICAL SUSPICION OF SPINAL DISEASE. E-M Larsson, M Heijling, and S Holt,s Department of Diagnostic Radiology, University Hospital, S-221 85 Lund, Sweden Between September 1987 and December 1990, NRI of the spine revealed unexpectedaertic pathology correlating with the patient's symptoms in five patients with clinical suspicion of spinal disease. MRI was performed with short TR/TE (500-600/30) and in one case also long TR/TE (2000/85) spin echo pulse sequences using a 0.3 Yesla scanner (FONAR B-3OOOM). No intraspinal pathology was found on HRI. However, one.paLient wiLh clinical suspicion of spinal stenosis had total occlusion of the aorta below the origins of the renal arteries, subsequently confirmed by aortography. In three patients spinal tumor was suspected, but HRI showed a ruptured pseudo-aneurysm of the lumbar aorta with a paraspinal hematoma in one, a dissection of the thoracic aorha in the second, and an abdominal aortic aneurysm in the third patient. In a patient who had become paraparetic after epidural anaesthesia during which he had a hypotensive episode, NRI revealed an abdominal aortic aneurysm. The aorta should be included in the routine MR evaluation of the spine. The occasional finding of aortic pathology explaining the patient's symptoms is an argument against the use of NRI techniques, such as rectangular field of view and presaturation which limit the visualization of the aorta.

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193 THE VARIABLE PRESENTATIONS OF CRANIOCERVICAL AND CERVICAL DURAL ARTERIOVENOUS MALFORMATIONS OF THE SPINE. K.G. terBrugge, R.A. Willinsky, W. Montanera, P. Lasjaunias. The Toronto Hospital - The Western Division The authors reviewed the charts and angiograms of four patients with dural arteriovenous malformations (AVM) in the upper spinal axis. Two patients presented with dural AVMs at the craniocervical junction and two patients had dural AVMs in the lower cervical region. In three of the four patients, the diagnosis was not made until laminectomy. All were male, ages 36 to 57. One of the patients whose AVM was at the craniocervieal junction presented with a slowly progressive thoracic myelopathy at T4. The other patient with an A V M a t this location presented with tinnitus and a 6th nerve palsy. Both of these A ~ s were fed predominantly by the ascending pharyngeal artery. One of the patients with a lower cervical dural AVM presented with a suharachnoid hemorrhage. The fourth patient presented with a progressive cervical myelopathy. This latter patient differed from the usual spinal dural AVM in that the venous drainage was predominantly extradural producing a compressive myelopathy. 2 of the patients had a successful obliteration of their A V M b y embolization. All patients showed clinical improvement by embolization. Dural AVMs of the spine remain an elusive diagnosis. High resolution angiography of the craniospinal axis must be done to make the diagnosis and plan treatment. In the face of subarachnoid hemorrhage with negative cerebral angiogram, the diagnosis must be entertained if there are symptoms referrable to the spinal cord or roots.

195 MRt AND NEUROLOGICALCOMPLICATIONSOF ADULT T-CELL LEUKEMIA J.L. Dumas (1,2), J M Visy (3), P Brugieres (4), F Lhote (5), P Vassel (6), J Amouroux (7) , D Goldlust (2) . 1: Institute of Tropical Neurology, Faculty of Medicine, Limoges 2: Dpt of Radiology Hopital Avicenne , University of Paris-Nord Bobigny. 3: Dpt of Neurology Hopital Laribolsiere Paris. 4: Dpt of Neuroradiology Hopital Henri-Mondor Creteil . 5: Dpt of Internal Medicine Hpt Avicenne 6: Dpt of Neurology Hpt Avicenne 7: Dpt of Anatomopathology Hpt Avicenne. PURPOSE : MRI assessmer~ of a lumbosacral localisation of Adult T-Cell Leukemia with HTLV-I infection and search of central nervous system associated involvement. MATERIALS AND METHODS : A 21 year-old woman from Ivory Coast presented a meningoradiculopathy with adult T-cell leukemia like cells in cerebrospinal fluid . Antibodies to HTLV-1 were positive in serum and CSF. She underwent lumbar spinal cord MRI (1.5 Tesla unit) with pre and post contrast medium sagittal and axial T1 weighted sequences before and after treatment. Brain MRI was performed with axial and coronal T2 weighted sequences . RESULTS : MRI revealed a conus medullaris pia mater enhancement extended to proximal spinal roots suggestive of lymphomatous infiltration . After polychemotherapy we observed a complete disappearance of the enhancement . Brain MRI detected multifocal lesions of increased signal intensity in the subcortical white matter . CONLUSION : MRt displays the direct infiltration by tumor cells and is necessary to characterize an associated subclinical impairment of CNS . It is important to underline that brain MR findings are similar to those observed in HTLV-] associated myelopathy, These MRI abnormalities are compatible with repoted necropsy findings in cases of Adult T-Cell Leukemia with neurological complications and have not been reported in literature

194 SERIAL ENHANCED MR SCANS IN MULTIPLE SCLEROSIS OF THE SPINAL CORD: CLINICAL IMPORTANC~ M.A. MIKHAEL EvanstonHospital-McGaw Medical Center of Northwestern University Evanston, Illinois PURPOSE: Detection of active multiple sclerosis disease which necessitates treatment and the correlation between the efficiency of treatment and the regression of the disease. METHODS: Fifty-eight cases of suspected multiple sclerosis of spinal cord were studied with MR before and after gadolinium enhancement. Serial studies for positive cases (21 cases) were obtained every 2 weeks. RESULTS: For confirmation of clinical diagnosis of multiple sclerosis, a T2weighted image (1M 2000 ms, TE 70 ms) of spinal cord is needed. For differentiation of old plaques from active acute disease that requires aggressive medical treatment, it was important to obtain post-enhanced MR OM 600 ms, TE 20 ms). Active acute plaques show enhancement after 20 ec of gadolinium-DTPA injected intravenously. Serial enhanced MR in patients receiving no treatment, showed theactive plaque to lose grthadUallyits clear delineated margins and high-intensity signal after the week and to lose completely the enhancement after 8 weeks. The segment of spinal cord that shows enhancement is usually swollen. The swelling lags behind loss of enhancement of the plaque. With successful treatment, periods of regression of enhancement are shortened according to the type of treatment; being steroids and/or plasmapheresis CONCLUSION: Enhancement of active plaques further stresses the fact that blood-brain barrier is disturbed in active multiple sclerosis lesions. For confirmation of clinical diagnosis of, a T2-weighted image of spinal cord is needed to visualize the plaques. The gadolinium is useful as a marker for new and clinically active lesions and should be used to follow-up the efficiency of medical treatment. In our series, the correlation between symptomatology and enhancement showed that the disappearance of enhancement slightly lags behind clinical improvement.

196 MRI OF PRIMARY AN~METASTATIC BONY LESIONS OF THE SPINE G.C. Dooms, M.A. Labaisse, J. Malghem, B. Maldague UCL Saint-Luc A prospective study was performed to assess the value of various imaging sequences for demonstrating bony lesions of the spine. The MR examinations were performed with a superconducting magnet (Philips Gyroscan SI5) operating at 1.5 Tesla. Various imaging sequences were performed : TI weighted (TR=415 and TE=20 msec) and T2 weighted (TR=I650 and TE=|O0 msec) spin echo, FFE T2 weighted (TR=500 and TE =35 msee, flip angle = 20 °) and STIR (TR=I000, Tl=140 and TE=20 msec) sequences. Fifty patients (age range 25-74 years) were included in the study : 38 presented with metastatic and 12 with primary (myeloma) bony lesions of the spine. MR findings were confirmed by biopsy, surgery or follow up MR studies in all patients. While T2 weighted images were very insensitive to bony lesions, FFE T2 weighted images detected mainly osteolytic implants as hyperintense lesions in 34 patients (12 myeloma and 22 metastases). TI weighted spin echo sequences were very sensitive but did not demonstrate all the bony implants, especially in young patients (hematopoietic base marrow); hurthermore, they demonstrated hypointense foci in 8 patients which corresponded to compact bone. STIR sequences demonstrated all the bony implants as hyperintense fool in all patients and permitted the differenti~ tion between bony lesions and compact bone. Combination of Tl weighted spin echo and STIR (poor signal to noise ratio) sequences appears the most useful for demonstrating bony lesions of the spine.

S 161

Concurrent Scientific Session (WFITN): Pediatric Applications Moderators: J.F. Bonneville, Besancon, Paris, France and M. Khangure, Perth, Australia 10.25 a m - •0.45 a m

Pediatric Interventional Neuroradiology P. Lasjaunias, Paris, France

10.45 a m - 11.10 a m

Scientific Papers 1 9 7 - 1 9 9

10.45 am-11.10 am Scientific Papers 197-199 197 Endovascular therapy of non-Galenic cerebral arteriovenous fistulae S.P. Lownie, G. g. Duckwiler, A. J. Fox, C.G. Drake, London, Canada 198 Vein of Galen fistula and arteriovenous malformations presenting in the first year of life: Comparison of outcome G.R. Duekwiler, J.E. Dion, E V. Vifiuela, P. Lylyk, Los Angeles, USA/Buefios Aires, Argentina

199 AVMs of the posterior fossa in children. Embolization by further miniaturized guide wire supported systems B. Richling, G. Bavinzski, Vienna, Austria

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Pediatric Interventional Neuroradiology P. Lasjannias Neuroradiologie vasculaire, H6pital Bic~tre, Kremlin Bic&re, France Our practice in Pediatric Interventional Neuroradiology (PIN) has grown since our first case in 1975 to represent 16 years later 30°7o of our activity, with more than 100 interventions a year in the CNS (brain or spinal cord). 80% of children are below 10 years and 40o/o below 3 years. We have developed multiple techniques in Bic~tre and Toronto that allow us to work exclusively by femoral approach with 4F introducer sheath. No cut down has ever been made; catheterization from the femoral artery is achieved without guiding catheter, using predominantly mini torquer catheter in particular, in high flow lesions in children below 2 years. Technique is not the most important factor in PIN, decision making is of paramount importance and remains a challenge to explore. Knowledge of the diseases, is mandatory to determine the appropriate timing for embolization. In neonates and infants decision errors have major irreversible consequences, which does not mean that heroic procedures are acceptable and everything is permitted. Systemic, hydrodynamic and neurological manifestations can be predicted and managed with proper endovascular embolization but some partial treatment precludes easy cure. After 7 to 10 years of age, strategy is similar to that of adults. The following pathologies will be considered below 2 years: Vein of Galen Malformations - Cerebro-spinal AVMs or AVFs Hemangiom~ -

-

After 2 years of age: - Maxillo-facial AVMs Traumatic lesions Dural shunts Maxillo-facial and spinal tumors. -

-

-

Clinical manifestations (systemic) and spontaneous evolutions (cerebral atrophy, thrombosis) are characteristic, or even specific of that population. The usual concept of natural history over 20 years, or statistical risk of hemorrhage does not apply in young children, the challenge being the risk for the maturing brain, and the tolerable length of observation of a few month baby. In our group conjoined technical morbidity and mortality is inferior to 2% (including Vein of Galen malformation patients). In fact true morbidity in that population is represented by the lack of optimal clinical outcome: mainly unlegitimate mental retardation, related either to inappropriate timing or ongoing changing techniques, that precludes rationalisation of treatment. It also wrongly shifts the attention towards the technical side for what is exclusively learning on the clinical one. Results must be presented considering the overall management of the disease in order to appreciate the true value of patients selection.

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197 ENDOVASCULAR THERAPY OF NON-GALENIC CEREBRAL ARTERIOVENOUS FISTULAE SP Lownie, GR Duekwiler, AJ Fox, CG Drake, University Hospital, London, Canada and UCLA, Los Angeles, USA PURPOSE: To review the clinical, radiological and therapeutic experience with cerebral arteriovenous fistulae not involving the vein of Galen. MATERIAI~ & METHODS: Cerebral arteriovenous fistulae not involving the vein of Galen are uncommon lesions. In the combined experience of the University of Westera Ontario and the University of California at Los Angeles, 14 cases have been encountered, of which 10 were treated. RESULTS: Five patients were treated surgically by proximal occlusion of the feeding artery(ies), with excellent results in 4 and 1 death. Two of these patients had failed an endovaseular approach. Four patients were treated using endovaseular methods with excellent results in 3 and 1 death. One patient was treated with a combined approach with an excellent outcome. The results were similar to a review of cases encountered in the literature (excellent or good results in 23 0f26 treated patients). CONCLUSIONS: Cerebral arteriovenous fistulae not involving the vein of Galen are clinically distinct from vein of Galen aneurysms. Two-thirds of the patients presented over the age of two, and the clinical presentation was related to mass effect in two-thirds and seizures in one-third. The natural history of these fistulae appears to be related to the number of major arterial territories supplying the varix. Endovascular therapy has evolved as the preferred initial approach, with surgery as a generally fail-safe alternative.

199 AVM'S OF THE POSTERIOR FOSSA IN CHILDREN. E M B O L I Z A T I O N BY FURTHER MINIATURIZED GUIDE WIRE SUPPORTED SYSTEMS B. Richling, G. Bavinzski Department of Neurosurgery, University of V i e n n a Medical School AVM's located in the p o s t e r i o r fossa in children represent special problems not only due to hemodynamic effects to the brain stem but also due to the sometimes very low diameter of the feeding arteries. Endovascular access sometimes is limited rather by the diameter of the catheter tip in relation to the lumen of the feeding artery than by navigational problems. Semi-flowdependent soft miorooatheters (MAGIC) do not allow the approach into low diameter feeding arteries because of the reduced flow. Further miniaturized guide wire supported microcatheters (TRACKER i0) allow endovascular access to smallest cerebellar vessels not reachable by conventional microtechniques. This is possible dhe to decreased diameter of guide wire, catheter tip and shaft, the mechanical stability of the system remaining almost unchanged. Examples of accesses of pediatric cerebellar arteries or arteries to the medulla oblongata demonstrate the utility of this system. Dangers and risks caused by the use of a very thin microcatheter and guide wire are pointed out.

198 VEIN OF GALEN FISTULA AND ARTER/OVENOUS MALFORMATIONS PRESENTING IN THE FIRST YEAR OF LIFE: COMPARISON OF OUTCOME GR Duckwiler, JE Dion, FV Vinuela, P Lylyk UCLA School of Medicine, Los Angeles, California FLENq, Buenos Aries, Argentina PURPOSE The most common severe cerebral vascular malformation presenting in the first year of life is the Vein of Galen fistula. However, there are also non-Galenic vascular malformations which also present in this period. The purpose of this retrospective study is to determine outcome in these respective groups. MATERIALS AND METHODS Twenty-one patients treated by endovascular therapy for cerebral vascular lesions in the first year of life were reviewed. Fifteen patients had Vein of Galen fistula, and six had a variety of arteriovenous malformations. RESULTS Presenting symptoms for the Vein of Galen group with congestive heart failure in 13, seizures in I and hemorrhage in L In this group, 4 died, 2 immediately and 2 delayed. One patient had neurologic deficit. In the non-Galenic group, 5 presented with congestive heart failure, and one with hemiparesis. Three died, with one death delayed. One is currently in treatment with continued severe cardiac and liver failure. CONCLUSION Patients presenting in the first year of life with cerebral vascular malformations have a grave prognosis. However, advances in the techniques of embolization have improved the survival of these patients. In the subgroup of non-Galenic cerebral vascular malformation, the treatment options are more limited, and the survival rate is poorer.

S 164

Concurrent Scientific Session (WFITN): Radiosurgery, Recanalization Techniques Moderators: H. Zeumer, Hamburg, Germany and M. Negoro, Nagoya, Japan 11.15 am -11.35 am

Radiosurgical Applications in Neurological Diseases C. Lindquist, Stockholm, Sweden

11.35 am - 01.00 pm

Scientific Papers 200-209

01.00 pm-02.00 pm

Lunch

11.35 am-01.00 pm Scientific Papers 200-209 200 Fibrinolysis of middle cerebral artery thrombosis occurring during the neuroradiological interventional procedures

205 Local intraarterial fibrinolysis of acute basilar artery occlusion with tissue plasminogen activator: Is the use of a microcatheter necessary? J. Reul, A. Thron, M. Mull, Aachen, Germany

F. Turjman, G. Foa Torres, Y. Bascoulergue, J. Duquesnel, A. Casasco, A. Aymard, J. J. Merland, Lyon,Paris, France 206 201

Percutaneous transluminal angioplasty of cerebral arteries in arteriosclerotic disease

Local intraarterial thrombolysis in old patients g. Sieckmann, A. Wakhloo, M. Schumacher, Freiburg, Germany

S.A. Kadish, Riga, Latvia 207 Urokinase treatment in acute progressive stroke 202 Local thrombolytic therapy of thromboembolic occlusion of the middle cerebral artery H.C. Nahser, D. KOhne, E. Berg-Dammer, R. TOpper, Essen, Germany 203 Local thrombolytic therapy in occlusion of the middle cerebral artery

E Y. Tsai, V.B. Matovich, K.M. Alfieri, C.J. Meoli, S. J. Essma, Kansas City, Missouri, USA 208

Long term results of angioplasty of neck and head arteries in patients with cerebrovascular or vertebrobasilar insufficiency R. Kachel, St. Basche, S. Endler, Erfurt/Germany

M. Tsujimura, Kitakyushu, Japan 204 Local intraarterial fibrinolysis in central retinal artery occlusion M. Schumacher, D. Schmidt, A.K. Wakhloo, Freiburg, Germany

209 Management for common problems during carotid artery PTA E Y. Tsai, R.T. Higashida, V.B. Matovich, J.Y. Huang, Kansas City, Missouri, USA

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Radiosurgical Applications in Neurological Diseases C. Lindqvist Department of Neurosurgery, Karolinska Hospital, Stockholm, Sweden Some 2100 patients have been treated by Gamma Knife radiosurgery at the department of neurosurgery of the Karolinska in Stockholm. Vascular malformations, benign and malignant tumors and functional disorders have been treated.

Vascular malformations Arteriovenous malformations of the brain remain the most successful target for radiosurgical treatment. A retrospective analysis of 935 cases with a follow-up of more than 2 years has shown that the chances of complete AVM obliteration and the risks of undue radiation effects in the brain are closely linked to the volume treated and the dose delivered. A minimum dose of 25 Gy gives a 90% chance of obliteration. The risk of neurological deficits in small AVMs (up to 10 cc) can be kept at 2-30/0. With larger AVMs a higher risk must be taken or the dose reduced and a smaller chance of obliteration accepted. Obliteration in most patients occurs within 1 - 2 years but rarely later. The treatment can be repeated and/or combined with embolization in larger malformations. Dural arteriovenous malformations and spontaneous carotid-cavernous fistulas have been treated with a success rate similar to that of AVM treatments. Cavernous hemangiomas appear to be excellent objects for radiosurgery but a long term follow-up in 20 cases shows that undue radiation effects seem to be much more common with this diagnosis as compared to AVMs. In addition there are problems in defining an endpoint for the treatment as the imaging methods available do not show disappearance of the lesions. Venous angiomas of 11 patients have been treated. Although a few of them have disappeared radionecrosis occurred in conjunction with the treatment effect. At this time it therefore does not seem to be an indication for treating these lesions.

Benign tumors Acoustic neuromas without signs of mass effect up to 40 mm in diameter have been treated in over 300 patients. The CT followup of 227 patients showed decrease of tumor size in 50%, no change in 35°7o and increase in 15%. In 79 patients with radiologically proven tumor growth before treatment 42 tumors (53 °70) diminished in volume and 22 (28 % ) remained unchanged over 12-117 months (mean 42). In a subset of patients posttreatment hearing was improved in 3 ears (2070), unchanged in 34 (22%) and slightly impaired in 81 (53o70) whereas it was severely impaired or lost in 36 (23%). Even after 4 - 6 years unchanged hearing was shown in 7 of 26 ears and slight impairment in 17 of 26. These data compare favorably with the results o f microsurgery. In 1607o of patients facial nerve dysfunction appeared but it was transient in all patients although facial synkinesias occurred in some cases. A slight facial numbness was seen in 12O7o and a more severe in 8%. Mild to moderate sensory disturbances were always temporary but severe numbness left some degree of impairment. A shunt operation for hydrocephalus was required in 17 patients (8%) but in half of them (47%) it was already performed before the radiosurgery (Noren 1991). Meningiomas have been treated following unsatisfactory microsurgical removal or in patients with a high surgical risk. In 75 patients arrest of tumor growth or slight diminution of

tumor volume resulted. Many of these tumors were parasellar with invasion of the cavernous sinus. In several of these improvement was noted in the function of the motor nerves to the eye. Longer follow up is needed before the value of radiosurgery in meningiomas can be more reliably assessed. In a recent report from the Pittsburgh Gamma Knife group 13 of 24 tumors (54%) were reported to show a reduction in tumor volume on CT 1 2 - 3 6 months after radiosurgery (Kondziolka et al. 1991). Pituitary tumors with Cushing's syndrome, acromegaly, prolactin production, Nelson's syndrome and without endocrine activity have also been objects for radiosurgery. In 51 patients with Cushing's syndrome treated after target localization with pneumoencephalography 42 (82%) have shown remission but in 8 consecutive recent cases when tumor localization has been performed by stereotactic MRI all (100%) have shown remission. The possibility of accurate target localization is thus crucial and this fact is also confirmed by the results of treatment in acromegaly (R~ihn 1991). Pineal region tumors, craniopharyngeomas, low grade astrocytomas, trigeminal and facial neurinomas, Lindau and glomus tumors are other tumors treated. The long term results are currently under evaluation.

Malignant tumors Solitary metastasis and in some cases multiple metastasis respond well to Gamma Knife radiosurgery regardless of the nature of the primary tumor. More than 90 such tumors have been treated. Of the first 32 metastases in this series 13 completely disappeared and 17 diminished in volume by more than 75%. Malignant gliomas are rarely of a volume amenable to radiosurgery. However, it has been performed as a postsurgical adjuvant, as presurgical treatment or as the only treatment in some 20 cases. It does not appear that radiosurgery significantly changes the gloomy course of these cases.

Functional disorders Intractable pain in malignant disease, tremor in Parkinson's disease, pain in trigeminal neuralgia, anxiety, obsessive-compulsive disorders and focal epilepsy have all been objects of Gamma Knife radiosurgery. It is quite clear that lesions of the normal brain can safely be made by high dose gamma lesions for these disorders. Ablative procedures such as thalamotomy for malignant pain has, however, been largely abandoned for other techniques. The role of Gamma Knife radiosurgery for trigeminal neuralgia and Parkinson's tremor is currently being reexplored after stereotactic MRI has appeared as a more accurate method of localizing the targets for this procedure. Encouraging results have recently been achieved with bilateral Gamma Knife lesions in the anterior internal capsule for some severe psychoneurotic disorders in 17 patients. Stereotactic MEG (magnetoencephalography) is the most recent addition in the diagnostic armamentarium for localizing focal epilepsy. In 4 patients this new method has been able to achieve an improvement in localizing capability to the extent that Gamma Knife radiosurgery has become a feasible treatment alternative In these patients Gamma Knife radiosurgery was performed and in all of them some degree of seizure amelioration was achieved.

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FIBR1NOLYSIS OF MIDDLE CEREBRAL ARTERY THROMBOSIS OCCURING DURING THE NEURORADIOLOGICAL INTERVENTIONAL PROCEDURES

PERCUTANEOUSTRANSLUMINAL ANGIOPLASTYOF CEREBRAL ARTERIES IN ARTERIOSCLEROTIC DISEASE SA Kadish Latvian Medical Academy, Riga, Republic of Latvia

F. TURJMAN, G. FOA TORRES, Y. BASCOULERGUE, J. DUQUESNEL, A. CASASCOo A°AYMARD, J.J MERLAND HOPITAL NEUROLOGIQUE LYON ~ : TO report the effectiveness of thrombolysis of the MCA iatrogenic occlusion. Methods : 4 patients (from 2 institutions) who suffered MCA thrombosis as a complication of endovascular catheterism were treated by fibrinolysis. These patients referred for endovasct~ar treatment with aneurysm(3) or A.V.M (1). A neurologic deficit contrelateral to the catheterism was diagnosed during the procedure. Impaired consciousness occured later on in 2 patients. M.C.A occlusion was demonstrated angiographically and thrombolysis was decided subsequentely. Thrombolysiswas performed using a mierocatheter placed nearby the thrombus ; rt-PA 20 to 50 mg (3 cases) or urokinase 400 000 UI (1 case) was infused within 1 hour. This was followed by systemic administration of either rt-PA or heparin for the next 24 hours. Results : M.C.A repermeation was obtained within the first hour following the thrombolysis. However part of the distal branches remained partially occluded. The follow up angiograms showed complete resolution. The clinical status improved rapidly in all the patients, who completely removed in 1 to 5 days. Follow-up CT-Scan failed to reveal any ischemia or hematoma. Conclusion : Thrombolysisof the M.C.A occlusion due to iatrogenic fresh thrombus migration is an e f f e c t i v e technique.

From 1982 with a follow-up to 5 years 105 PTA procedures were performed in 100 patients. In 88 patients 142 stenoses were localized in the carotid system, in 12 patients 22 stenoses in the vertebral arteries. In the carotid t e r r i t o r y from 142 lesions 50 were localized on the extracranial segment and 80 lesions on the intracranial segment of the internal carotid artery. 10 stenoses in the middle cerebral artery and 2 stenoses in the anterior cerebral artery. Prior to the procedure 33 patients had slight, 52 patients moderate and 15 patients severe neurological deficit. Control angiography was performed in one week, 3 month, 6 month and 1 year intervals. 3 patients showed restenoses, 2 of which underwent additional PTA. In 2 patients PTA was unsuccessful. Complete recovery of the neurological d e f i c i t was seen in 54 patients, improvement in 37 patients. Neurological status was unchanged in 6 patients. There was no morbidity from these procedures, mortality was 3%. PTA was most effective when performed within 9 days to 3 months following onset of the stroke. The best clinical results were obtained in patients with slight neurological d e f i c i t . PTA of cerebral arteries is an effective therapeutic method in indicated ischemic strokes.

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LOCAL THROMBOLYTIC

T H E R A P Y OF T H R O M B O E M B O L I C

O C C L U S I O N O F THE M I D D L E C E R E B R A L A R T E R Y H. C. N A H S E R ,

D. KUHNE,

E. B E R G - D A M M E R , R. T O P P E R

T h r o m b o l y t i c a g e n t s h a v e a p o t e n t i a l r o l e in t h r o m b o e m b o l i c o c c l u s i o n of the MCA. T h e s y s t e m i c u s e of t h r o m b o l y t i c a g e n t s c a r r i e s a n una c c e p t a b l e r i s k of c e r e b r a l h e m o r r h a g e o r m a y e v e n b e c o n t r a i n d i c a t e d in l e s i o n s b e i n g e n d o v a s c u l a r t r e a t e d . In a c o n s e c u t i v e s e r i e s of 1252 n e u r o i n t e r v e n t i o n a l p r o c e d u r e s 5 p a t i e n t s d e v e l o p e d a t h r o m b o e m b o l i c M C A o c c l u s i o n . The lesions treated were spontaneous cavernous sinus fistula, occipital dural fistula, AcomP aneurysm and meningeoma. Urokinase was applied b y a m i c r o c a t h e t e r p l a c e d in the t h r o m b u s i m m e d i a t e l y a f t e r c l i n i c a l o n s e t of s y m p t o m s . In all p a t i e n t s r e v a s c u l a r i z a t i o n w a s a c h i e v e d . R e c o v e r y w a s c o m p l e t e in 4 a n d a mild neurol o g i c a l d e f i c i t p e r s i s t e d in ~ p a t i e n t , w h i c h h a d the m e n i n g e o m a o p e r a t e d 14 d a y s a f t e r t h r o m b o l y t i c t h e r a p y . In no p a t i e n t t h e r e w a s h e m o r r h a g i c t r a n s f o r m a t i o n in the d i s t r i b u t i o n a r e a of the MCA. It is c o n c l u d e d t h a t in the c a s e s of t h r o m b o embolism induced by angiographic catheters l o c a l t h r o m b o l y t i c t h e r a p y is s a f e a n d efficacious.

LOCAL TflRONBOLYTIC THERARY IN OCCULUSION OF THE MIDDLE CEREBRAL ARTERY M. TSUJIMURA, Department of Neurosurgery, Kitakyushu city Yahata Hospital Local thromholytic therapy by means of urokinase was performed on 4 patients for suffering from occulusion of the middle cerebral artery (MCA). All patients with angiographically defined MCA occulusion were treated within 3 hours of symptom onset. After advancing the catheter to MCA, 240,000 - 720,000 units urokinase in 50 mR was continuously infused into the artery. Immediate recanalization was achieved in 4 patients: in two patients, recanalization appeared complete: in the others partial occulusion was seen in the branches. In two patients with stuporous and hemiplegia symptoms ameliorated quickly, and steadily improved. The other patients with global aphasia and hemiplegia improved, hut only displayed minimum aphasia. CTs obtained after onset demonstrated no evidence of c ~ e b r a l infarction in all patients. SPECT images with mTc-hexamethyl propyleneamine oxime (HM-PAO SPECT) after recanalization showed hypoperfusion in the watershed zone in two patients, hyperperfusion in one patient, and normoperfusion in one patient. The present study indicated that local thrombolytic therapy for acute thromboembolic occulusion on the middle cerebral artery might be effective and PX~-PAO SPECT might be useful to assess and predict the prognosis for cerebral infarction after reoanalization.

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L O C A L I N T R A A R T E R I A L F I B R I N O L Y S I S IN C E N T R A L R E T I NAL ARTERY OCCLUSION

LOCAL INTRAARTERIAL FIBRINOLYSIS OF ACUTE BASILAR ARTERY OCCLUSION WITH TISSUE PLASMINOGEN ACTIVATOR: IS T H E U S E O F A MICROCATHETER NECESSARY ? Reul, A. Thron, M. Mull Neuroradiologie, Klinikum RWTH Aachen, P a u w e l s s t r a ~ e 30, 5100 A a c h e n

M. Schumacher*, D. Schmidt** and A.K. W a k h l o o * S e c t i o n of N e u r o r a d i o l o g y * and Dep. of O p h t h a l m o logy**, U n i v e r s i t y of F r e i b u r g C e n t r a l retinal a r t e r y o c c l u s i o n is k n o w n to h a v e a p o o r n a t u r a l o u t c o m e a n d also c o n v e n t i o n a l t h e r a p e u t i c p r o c e d u r e s e.g. paracentesis, h e m o d i l u t i o n or local m a s s a g e s h o w p o o r results. C o m p a r a b l e to i n t r a a r t e r i a l f i b r i n o l y t i c t h e r a p y in int r a c e r e b r a l v e s s e l s we a p p l i e d this m e t h o d also to the t e r r i t o r y of the o p h t h a l m i c a r t e r y in i0 pat i e n t s w i t h o c c l u s i o n of the central retinal artery. The local fibrinolysis was done w i t h a m i c r o c a t h e t e r s u p e r s e l e c t i v e l y p l a c e d into t h e p r o x i m a l p o r t i o n of the o p h t h a l m i c artery. The a m o u n t of urokinase varied from 200. 000 to 900. 000 IU d i l u t e d in saline solution. In 8 p a t i e n t s fluoresc e i n a n g i o g r a p h y was c a r r i e d out b e f o r e and a f t e r f i b r i n o l y t i c t h e r a p y c o n f i r m i n g the s i g n i f i c a n t i m p r o v e m e n t of retinal and choroidal p e r f u s s i o n seen on t h e a r t e r i a l o p h t h a l m i c angiogram. All p a t i e n t s s h o w e d an i m p r o v e m e n t of v i s u a l funct i o n a f t e r therapy, 3 p a t i e n t s even h a d a c o m p l e t e r e c o v e r y of v i s u a l acuity.

10 p a t i e n t s w i t h c l i n i c a l s i g n s o f a c u t e ischemic b r a i n s t e m d a m a g e a n d a n g i o g r a p h i c a l l y veryfied occlusion of the basilar artery underwent local intraarterial fibrinolysis with r-TPA. 7 patients were treated with a p p l i c a t i o n of r-TPA in the distal p o r t i o n of t h e v e r t e b r a l a r t e r y ( g r o u p i), 3 p a t i e n t s were treated by using a microcatheter and application just before the thrombus (group 2), in b o t h g r o u p s u s i n g t o t a l d o s e s b e t w e e n 65 and i00 mg. C l i n i c a l l y deep coma w a s found in 8 patients, p r o g r e s s i v e s o m n o l e n c e in two. Complete or partial recanalisation of the b a s i l a r a r t e r y w a s a c h i e v e d in 6 c a s e s (all g r o u p I). 2 p a t i e n t s s u r v i v e d w i t h s e r v e r e d e f i c i t ( g r o u p 2). 2 p a t i e n t s d i e d (one of every group). No intra- or extracranial b l e e d i n g s h a d b e e n observed. W e c o u l d o b s e r v e a high recanalisation rate in the group treated without a microcatheter correlated with good clinical outcome. The results s u g g e s t t h a t t h e u s e of a m i r o c a t h e t e r w i t h s u p e r s e l e c t i v e a n g i o g r a p h y (sometimes c a u s i n g an i m p o r t a n t loss of time) is n o t n e c e s s a r y . R e g a r d i n g t h e e f f e c t i v e n e s s a n d d u r a t i o n of fibrinolysis r - T P A seems to be s u p e r i o r to the up t o n o w u s e d fibronolytica.

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LOCAL INTRAARTERIAL THROMBOLYSIS IN OLD PATIENTS

UROKINASE TREATMENT IN ACUTE PROGRESSIVE STROKE FY Tsai, VB Matovich, KM Alfieri, CJ Meoli, SJ Essma. University of Missouri-Kansas City, School of Medicine Truman Medical Center

R. Siekmann, A. Wakhloo.and M. Schumacher Section of Neurorsdiolgy, University of Freiburg, FRG

The local intraarter|al fibr|nolysis (UF) in acute thromboembolic occlusion is an established treatment in the vertebrobasilar-system. Recently good results of UF-therspy of the middle cebral artery (MCA) have been reported. Beside other factors age has been regarded as a limiting factor for clinical outcome. We present three cases at the age of 77,80 and 83 with acute occlusion of the basilar artery, the main branch of the MCA and the pericallosal artery respectively. In the first two patients LIF was performed with a total amount of 800.000 I.U. Urokinase applicated within two hours. In the 83 years old patient 30 mg rtPA were aplied. The treatment was initiated nine six and 1,5 hours after onset of stroke respectively. The patient with basilar artery occlusion showed a complete recanallzation and fully clinical recovery. The anglography after UF in the second patient demonstrated reopening of MCA main branch. CT-control revealed an incomplete Infarction of the MCA with no hemorrhage. Angiography one day after treatment showed the vessel being patent. The third patient recovered from hemiparesis after complete recanalizatlon of the pericallosal artery. The three cases demonstrate that age is not a general contraindication for intraarterial fibrinolysls.

Stroke may be due to several causes, thromboembolism remains as an important factor. Preservation of cerebral blood flow to the target structure is essential to prevent or treat stroke. Numerous methods have been reported in the literature intended to treat and/or to prevent stroke from the thromboembolic insult. Anticoagulant treatment is widely used to treat those patients suffering from stroke. However, nearly 25% of patients may progress into worse conditions and deterioration despite an anticoagulant treatment. We have those patients suffering progressive stokes requiring thrombolytic treatment in addition to anticoagulants. Progressive stroke may be due to either arterial thrombus or dural sinus thrombosis. We have treated 27 patients with acute progressive strokes: 24 patients from arterial system and 3 patients due to intracranial dural sinus thromboses. Among the 24 patients, 13 patients-carotid artery and 8 patients-vertebrobasilar artery; 3 patients failed to respond to intra-arterial treatment and one of those patients had hemmorhagic complications. We wish to present our experiences in detail.

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LONG TERM RESULTS OF A N G I O P L A S T Y OF N E C K A N D HEAD ARTERIES IN P A T I E N T S WITH CEREBROVASCULAR OR VERTEBROBASILAR INSUFFICIENCY Kaohel,R. , Basche.St. , Endler,S. Clinic of Radiology, Medical Academy EPfuPt/FRG

MANAGEMENT FOR COMMON PROBLEMS DURING CAROTID ARTERY PTA FY Tsai, RT Higashida, VB Matovich, JY Huang. University of Missouri-Kansas City School of Medicine Truman Medical Center

We present our experience with 125 patients in w h o m a n g i o p l a s t y (PTA) was performed in 1 3 2 stenosed or o c c l u d e d neck and head arteries. Symptoms of c e r e b r o v a s c u l a r and/or vertebrobasilar insufficiency were present in 1 2 4 p a t i e n t s of the 125 patients. PTA was successful in" 44 stenoses of the carotid artery, 18 s t e n o s e s of the vertebral artery, 4 stenoses of the innominate artery, 52 s t e n o s e s of the subclavian artery and S occlusions of the subclavian artery. There were only 1 major-complication (permanent neurological deficit) and 4 minor-complications (2 h a e m a t o m a s , 1 transient ischemic attack, 1 small thrombus of the internal carotid artery which was detected by 1 1 1 - i n d i u m platelet sclntigraphy and treated by t h P o m b e n d a r t e r e c t o m y ) . : After successful PTA patients were symtomfree.. During observations p e r i o d o f 3 to 116 m o n t h s (average: 61 m) t h e r e w e r e o n l y t w o p a t i e n t s with restenosis after subclavian angioplasty. The short and lone term results of more than n 750 own and international published PTA's of neck and head arteries are presented. The results suggest t h a t P T A is an e f f e c t i v e method. On s t r i c t d e f i n i t i o n of the indication the complication r a t e is n o t l i k e l y to be h i g h e r that for operative treatment.

Although PTA of carotid artery was first reported by Mathias, et al, in 1980 along with Kerber, et al, for retrograde intraoperative angioplasty, this technique has received very little attention for the treatment of carotid stenosis. The primary concern is the fear of distal embolization from dislodging debris during angioplasty. It took a little more than a decade to overcome the initial barrier. Recently, this technique started gaining some attention and several modified techniques have been reported in literature to improve the safety for PTA of carotid artery. However, based on those reports, distal embolization has not been a major complication. Over the past eight years, we have not had any clinical complications resulting from distal embolization. Several potential complications may be encountered during PTA. Rupture of the artery or vascular wall injury may be avoided by using an optimal sized balloon rather than overdilatation, If a partial dilatation is the result of a first try due to hardening of vascular wall at the stenotic site, second dilatation is deferred at least one month later rather than using an oversized balloon to redilate the p a r t i a l l y d i l a t e d artery. The most c o ~ o n problems which we have faced over the past eight years are transient ischemia and spasm. Injection of fresh heparinized arterial blood and nitroglycerin with urokinase have helped us overcome those problems in the past. We wish to present our experiences in detail.

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Scientific Session (WFITN): Brain AVMs Moderators: E Vifiuela, Los Angeles, USA and V.V. Halbach, San Francisco, USA 02.00 pm-02.20 pm

Endovascular Treatment of Cortical AVMs A. Valavanis, Zurich, Switzerland

02.20 p m - 02.40 pm

Endovascular Treatment of Deep and Posterior Fossa AVMs L. Picard, Nancy, France

02.40 p m - 02.45 pm

Discussion

02.45 pm-03.35 pm

Scientific Papers 210-215

03.35 pm - 04.00 pm

Coffee Break

02.45 pm-03,35 pm Scientific Papers 210-215 210

Combining endovascular therapy and surgery in the management of cerebral arteriovenous malformations: Experience with 101 cases

J.E. Dion, F.V. Vifiuela, G.R. Duckwiler, N. Martin, P. Lylyk, A. Fox, D. Pelz, C.C. Drake, J. Girvin, G. Debrun, Los Angeles, USA 211

Ethibloe embolization for brain AVM

M. Negoro, T. Handa, S. Miyachi, K. Sugita, Nagoya, Japan 212 The role of a new embolization technique for the treatment of brain AVM

K. Goto, N. Ogata, S. Iwabuchi, H. Matsuno, W. Taki, H. Iwata, Fukuoka, Kyoto, Osaka, Japan 213 Changes in feeding artery pressure during embolization of arteriovenous malformation

T. Handa, M. Negoro, S. Miyachi, K. Sugita, Nagoya, Tokyo, Japan

214

Treatment of brain arteriovenous malformations (AVMs) with combined embolization and gamma knife radiosurgery

L.A. Lemme-Plaghos, C.J. Schonholz, A.B. Chinela, J.A. Guevara, J.C. Antico, H.J. Bunge, Buefios Aires, Argentina 215 GammaKnife radiosurgery in infratentorial arteriovenous malformations (AVMs)

H.J. Bunge, A.B. Chinela, J.A. Guevara, J. Antico, L. Lemme-Plaghos, Buefios Aires, Argentina

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Endovascular Treatment of Cortical AVMs A. Valavanis Neuroradiology, University Hospital of Zurich, Switzerland Correlation of multiplanar Tl-weighted MR with superselective digital subtraction angiograms in cases of so-called cortical brain AMV's allows to classify these lesions intro three types, i.e. sulcal, gyral and mixed type AVMs. Sulcal AVMs are located within a specific sulcus adapting to its contours and thus exhibitinga pyramidal shape. They obliterate and expand this sulcus and compress the adjacent gyri. Sulcal AVMs may extend in the depth of the sulcus through cortex into the subcortical white matter. The main arterial supply to sulcal AVMs is from cortical-pial arteries terminating into the AVM nidus. More than 50% of sulcal AVMs receive additional supply from dural arteries. If there is a subcortical extension, this is usually supplied by perforating arteries. Since the cortical-pial arteries represent terminal type feeders and the dural supply is usually easily accessible by the endovascular route, embolization represents a major indication for sulcal AVMs. In fact, approximately 70o70 of small and medium-sized sulcaI AVMs can be completely obliterated with the use of NBCA, without significant morbidity. Gyral AVMs are located within a specific gyrus and have a round or oval shape. They expand the gyrus and compress the adjacent sulci. Larger gyral AVMs extend from the gyra] white matter into the subcortical and periventricular white matter.

The main arterial supply is from intracortical branches of the cortical-pial arteries. Therefore, the feeding cortical-pial arteries represent transit-type feeders and participate into the supply of normal brain distal to the AVM. Deep extensions receive supply from perforating arteries. Characteristically, gyraI AVMs lack dural supply. Since the size of the majority of the intracortical feeding arteries is less than the size of the currently available microcatheters, safe embolization of gyral AVMs is only exceptionally possible. These lesions represent a major indication for microsurgical removal. Only 1 0 % - 15% of gyral AVMs can be obliterated by embolization. Mixed-type AVMs are large lesions occupying adjacent sulci and gyri and invariably extending into the periventricular white matter. They combine the angioarchitectural features of sulcal and gyral AVMs. The optimal treatment is preoperative embolization of the sulcal portions followed by microsurgical removal of the gyral portions. This classification provides new insights into the structural and vascular characteristics of so-called cortical AVMs and should be used in order to plan treatment. The embolization techniques used for each type of AVM and the results obtained in 78 cases will be detailed.

Endovascular Treatment of Deep and Posterior Fossa AVMs L. Picard Department of Diagnostic and Interventional Neuroradiology, University Hospital, Nancy, France Endovascular treatment of brain AVMs is in permanent progress since the last fifteen years. Among 401 patients with an AVM investigated by hyperselective angiography in the last ten years, 74 (18.5°70) were deep seated whereas 30 (7.5%) were in the posterior fossa. However, deep located and posterior fossa AVMs are the most difficult to treat because for anatomic and functional reasons. From a functional point of view, there is often a narrow gap between the nidus and the normal brain tissue which explains the high risk of neurological deficit after embolization. A perfect knowledge of microangiographic anatomy is essential to establish what is possible to embolize with reasonable risks. Inside the anterior choroidal artery or thalamo-perforating branches, the difference between good embolization and disastrous complications may be a matter of few millimeters. The usual multiplicity of feeding pedicles requires a wellconsidered choice in order to find the most efficient and the less dangerous one.

In the posterior fossa, technical problems increase because of difficulties to obtain a correct visualization with fluoroscopy: general anesthesia is often necessary. From a technical point of view, to obtain a permanent occlusion, we must use N. Butyl polymer like histoacryl. Association of embotization and stereotactic radiation therapy provides more and more excellent results so that we are able to widen our indications. The high haemorrhagic risk of deep brain AVMs justifies a more aggressive attitude. In the posterior fossa, cerebellar localizations must be treated. For the brain stem we must be very cautious: some AVMs can stay asymptomatic during many years so that sometimes abstention or isolated stereotactic radiation therapy can be the best solution.

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COMBINING ENDOVASCULAR THERAPY AND SURGERY IN THE MANAGEMENT OF CEREBRAL ARTERIOVENOUS MALFORMATIONS: EXPERIENCE WITH 101 CASES. JE Dion, FV Vinuela, GR Duckwiler, N Martin, P Lylyk, A Fox, D Pelz, CC Drake, J Girvin, G Debrun.

ETHIBLOC EMBOLIZATION F O R B R A IN A ~ M. N e g o r o , T . H a n d a , S. M i y a c h i , K. S u g i t a Department of Neurosurgery, Nagoya University S c h o o l of M e d i c i n e , N a g o y a , J a p a n

PURPOSE To describe the overall experience in the combined use of endovascular therapy followed by surgical removal in 101 brain artefiovenous malformations. MATERIALS AND METHODS Presentations were as follows: 53 with inlracranial hemorrhage, 35 with seizures, and the remainder asymptomatic. Using Spetzlers classification, there were 2 type I, 13 type II, 26 type Ill, 43 type IV, and 17 type V AVM's. Fifty one were in the fight hemisphere, 28 in ~he left hemisphere, 12 in the corpus callosum and 5 involved in the cerebellum. RESULTS In 50 cases, a presurgical obliteration of 50-75% of the nidus was achieved; in 31 cases, this percentage was in the order of 75-90%. In 97 of 101 cases, a complete surgical removal was achieved. The morbidity from preoperative endovascular therapy was classified as mild in 3.9%, moderate in 6.9% and severe in 2% of cases. The death rate of embolization was 0.9%. The immediate surgical morbidity was classified as mild in 5.9%, moderate in 10.8% and severe in 5.9% of cases. The overall, long term morbidity was mild in 5.9%, moderate in 6.9% and severe in 2%. Two patients died due to intractable intraoperative hemorrhage (1.98%) and 2 from postsurgical pulmonary complications (1.98%). CONCLUSION The authors have found the combination of endovascular therapy and surgical treatment of brain AVM's to result in a vast majority of cures with an acceptable morbidity and mortality rate, in properly selected patients.

Objective:Ethibloc, a derivative of corn protein, has been used for embolization of tumors in the abdomen. It immediately precipitates i n b l o o d as a c a s t and i s a b l e t o o c c l u d e t h e v e s s e l s w i t h o u t recanalization. The p u r p o s e o f t h i s s t u d y i s t o prove the efficacy and s a f e t y of E t h i b l o c in b r a i n AVM e m b o l i z a t i o n . ldethod:Embolization procedure is carried o u t in 15 p a t i e n t s harboring surgically difficult AVMs. Feeding arteries are catheterized as s e l e c t i v e as possible using a Tracker-18 catheter a nd a m i x ture of Ethibloc and Lipiodol(2:l) is injected until the eecessation of flow in the vessels. Result:Post-embolization a n g i o g r a m r e v e a l e d complete obliteration i n l , 70-900/o o b l i t e r a t i o n in 5 a nd l e s s t h a n 50% i n 4. S i x c a s e s w e r e t o t a l l y r e m o v e d by s u r g e r y f o l l o w i n g e m b o l i z a t i o n . No o p erative difficulty is experienced d u r i n g t h e r em o v a l o f AVN n i d u s . No i n t e n s e inflammatory reaction is observed around embolized vessels in surgical s p e c i m e n s . F o l l o w - u p a n g i o g r a m o f completely obliterated case failed t o s how a n y s i g n s of r e c a n a l i z a t i o n . This material is not adhesive a nd m a k e s r e p e a t e d injections possible without withdrawal of t h e c a t h e t e r . Conclusion:Ethibolc,as an e m b o l u s f o r b r a i n AVM, has following advantages. 1.easy to inject through a microcatheter 2.able to inject repeatedly without gluing 3.easy to resect surgically after embolization

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THE ROLE OF A NEW EMBOLIZATIOIN TECHNIQUE FOR THE TREATMENT OF BRAIN AVM

CHANGES IN FEEDING ARTERY PRESSURE DURING EMBOLIZATION OF ARTERIOVENOUS MALFORMATION T. Handa, M. Negoro, S. Miyachi, K. S u g i t a

K. Goto, N. Ogata, S. Iwabuchi, H. Matseno* W. Taki** H. Iwata*** * Iizuka Hospital, Fukuoka, Japan ** Kyoto University, Kyoto, *** Natl Cardiovase Ctr, Osaka,Japan

D e pa rt me nt of N e u r o s u r g e r y Nagoya U n i v e r s i t y School of Medicine

PURPOSE: Study of efficacy and complication of newly developed embolization technique in the treatment of brain AVM. METHODS: Using a newly developed plastic guide wire, a microcatheter was superselectlvely cann~ated deep into the feeding pedicles. A new embofie agent EVAL(ethylene vinyl alcohol) was injected under flow restriction generated by second balloon catheter. Most of the 32 brain AVMs embolized for the last 2 years, usning a new technique, were high flow and large AVMs. RF~ULTS: 23 cases showed more than 90% obliteration of the nidus by embolization. 21 of these were successfully removed by surgery, and 5 were submitted to gamma knife therapy. Complication was seen in 6 eases, and 2 of them were hemorrhages. There were 2 delayed bemorrheges. Most of the complications ocarred in the initial cases on which many feeding pedicles were embolized in one session. 3 of the hemorrhagic cases died. Tendency of recanalization was seen in 11 cases during surgery or on follow up angiography. Histological studies of surgical specimen showed that ilLfl~mm~tory reaction evoked by EVAL was mild. CONCLUSION: Our technique might be proved to be effective as presurgical procedure for brain AVM. In order to prevent hemorrhagic complications, the final session of embolization should be scheduled shortly before surgery.

R e c e n t l y s u p e r s e l e c t i v e e m b o l i z a t i o n of AVMs is p o s s i b l e as a r e s u l t o f t h e d e v e l o p m e n t of microc a t h e t e r s . H o w e v e r , hemorrage, r e t r o g r a d e t h r o m b o s i s and m i g r a t i o n o f embolic m a t e r i a l s i n t o v e s s e l s s u p p l y i n g norma l p a r e n c h y m a remain major c o m p l i c a t i o n s . I t is i m p e r a t i v e t o a s s e s s t h e volume of embolic m a t e r i a l t h a t i s n e c e s s a r y t o o c c l u d e t h e n i d u s and when t o t e r minate t h e p r o c e d u r e . Changes in f e e d i n g a r t e r y p r e s s u r e were measured t h r o u g h t h e T r a c k e r 18 c a t h e t e r a t multiple stages, including p re; intra; and poste m b o l i z a t i o n . The p r e s s u r e i n c r e a s e d g r a d u a l l y as a v e s s e l was e mbol i z e d and o c c l u d e d . In most c a s e s , i f embolization was s u c c e s s f u l as a s s e s e d b y c o m p l e t e obliteration, the feeding artery pressure went up a p p r o x i m a t e l y 70~ t o 804 of b r a c h i a l a r t e r i a l p r e s s u r e . We p r o p o s e t h a t t h i s p r e s s u r e e l e v a t i o n i n d i c a t e s t h a t t h e e mbol i z e d v e s s e l is n e a r c o m p l e t e o c c l u s i o n . Assessment of t h e a n g i o g r a m s i s o n l y an I n d i r e c t i n d i c a t i o n of c h a n g e s in b l o o d flow and i s most a c c u r a t e when a s s e s s i n g c o m p l e t e o b l i t e r a t i o n of a nidus. The measurement of f e e d i n g a r t e r y p r e s s u r e d u r i n g m u l t i p l e i n j e c t i o n s may be o f v a l u e in a s s e s s i n g when s u f f i c i e n t embolic m a t e r i a l ha s be e n i n j e c t e d and may c o n s e q u e n t l y d e c r e a s e t h e m o r b i d i t y and m o r t a l i t y a s s o c i a t e d w ith sophisticated embolization techniques.

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TREATMENT'OF BRAIN ARTERIOVENOUS MALFORMATIONS (ArMs) WITH COMBINED EMBOLIZATION AND GAMMAKNIFE RADIOSURGERY.

GAMMA KNIFE RADIOSURGERY IN INFRATENTORIAL ARTERIOVENOUS MALFORMATIONS (AVMs).

LA Lemme-Plaghos, CJ Schonholz, AB Chinela, JA Guevara, JC Antico and HJ Bunge.

HJ Bunge, AB Chinela, JA Guevara, J Antico, L Lemme-Plagh6s

Buenos Aires Gamma Knife Centre, Buenos Aires, Argentina.

The e f f i c a c y of Gamma Knife radiosurgical treatment in brain AVMs has already been demonstrated, though no d e f i n i te c r i t e r i a has been established f o r those lesions located in the p o s t e r i o r fossa where - even with very steep isodose gradients - the brainstem mat receive considerable single dose i r r a d i a t i o n . F i f t y cases o f i n f r a t e n t o r i a l AVMs were i r r a d i a t e d f o l l o wing the p r i n c i p l e s of s t e r e o t a c t i c radiosurgery. Ten cases were deep central while the other 40 were convexity AVMs. Three patients had undergone transarterial embolization pre viously while another one had had a partial resection. Thir ty seven patients are under current follow up, 22 o f whichhave completed the protocolized two year control angiogram which showed total o b l i t e r a t i o n in 19 cases (86.4%), part i a l obliteration in 2 (9%) and no changes in one. One pat i e n t died as compl]caZion of a rebleeding during the latency period. The single dose delivered to the periphery of the AVMs ranged from 2000 to 2500 cGy and seems to be optimal to pro duce vascular o b l i t e r a t i o n , while the dose received by the brainstem ranged from 1000 to 3000 cGy (mean 1400 CGy) with no undesired side effects detected in the patients under clinical follow up. Since our data demonstrates the succesfull results of Gamma Knife radiosurgery in i n f r a t e n t o r i a l AVMs - even the se closely located to the brainstem - we conclude that i t should be considered as an alternative to conventional sur gery and a usef u l l complementary treatment f o r p a r t i a l l y embolized AVMs in this location.

Transvascular embolization in brain'AVMs presehts as main limitation the residual clusters of angioma with non catheterizable feeders, which may be the origin o f revascularization and/or rebleedings, Complementary stereotact i c radiosurgery on these remaining nidus should promote further occlusion thus avoiding the previously described risks. Twenty-five patients of our series underwent combined therapy with superselective embolization followed by Gamma Knife Radiosurgery, 16 of which have had at least a two year follow up, latency period considered necessary to asses radiosurgical outcome. Complete occlusion was observed in 4 cases, subtotal occlusion (80% or m~)re) in 5, and partial occlusion (80% or less) in other 5. One patient died because of a rebleeding one year after treatment. In 7 cases of subtotal or partial occlusion i t was decided to wait a third year follow up angiogram expecting further occlusion due to dela#ed effects o f radiosurgery. In the other 2 cases reirradiation was performed. Deep analysis of the follow up angiograms has shown that at least a two month period should elapse between proccedures in order to avoid insufficient residual nidus i d e n t i f i cation related to inmediate post embolization hemodinamic redistribution and early repermeabilization. Delayed revas cularization was observed in three cases in which particuS late emI~olic agents had been used while minimal revascularization was observed in a case embolized with NBCA. Although our data shows the efficacy of the combined treatment, we believe that f6fither improvement in embolotherapy techniques a~d ~mbolic agents will increase the current cure rates.

Buenos Aires Gamma Knife Centre, Buenos Aires, Argentina.

S 173

Scientific Session (WFITN): Brain AVMs Moderators: C. Strother, Madison, USA and P. Lylyk, Buefios Aires, Argentina

04.00 pm-04.40 pm

Scientific Papers 216- 220

04.00 pm-04.40 pm Scientific Papers 216-220 2t6

Intravascular treatment of brain AVMs: Protocol of treatment and results for 185 patients Y.P. Gobin, A. Laurent, A. Aymard, A. Casasco, A. I. L. Bailly, B. Georges, J.J. Merland, Paris, France

217 Endovascular treatment of brain AVMs L. Guimaraens, N. Fayed, E.G. Cervigon, V. Vazques Afion, P. Zubiaur, Zaragoza, Spain 218 Embolization of eerebellar AVM M. Sonobe, S. Takahasbi, K. Sugita, Mito, Japan

219 Emergent endovascular management of CNS AVMs false aneurysm and hematomas R. Garcia Monaco, G. Rodesch, K. terBrugge, P. Lasjaunias, Paris, France 220 Angiographic obliteration of arteriovenous malformations following embolization K.J. Gibbons, L. g. Guterman, A. Ahuja, L.N. Hopkins, Buffalo, USA

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tNTRAVASCULAR TREATMENT OF BRAIN AVMS: PROTOCOL OF TREATMENT AND RESULTS FOR 185 PATIENTS

ENDOVASCULAR TREATMENT OF BRAIN AVM'S

YP Gobin, A Laurent, A Aymard, A Casasco, AL Bailly, B Georges, JJ Merland Dpt of Neurovascular Disease, Hopital Lariboisi~re, Paris, France From 1984 to 1990, 185 patients were treated by an endovascular approach. In most of the cases, AVM was judged too large or located in eloquent areas and was not accessible to direct surgery or stereotactic radiotherapy. Embolization was performed to make the AVM suitable for surgery or radiotherapy, or to eradicate it completely in the rare cases of small AVMs. Most embolizations were performed with glue. Our therapeutical protocol and results will be presented and discussed.

L. GUIMARAENSI;.N. FAYEDI; E.G. CERVIGON2; V. VAZQUEZ A~ON±; P. ZUBIAUR ± i- CLINICA QUIRON ZARAGO ZA. 2- HOSPITAL J. CANALEJO. LA CORU~A. SPAIN. PURPOSE: TO evaluate the results of the endovascu lar treatment in patients with brain AVM' S. MATERIAL AND METHODS: Between 1985-1991. 72 patients were treated among 95 patients. Treatment decisions were made by a multidisciolinary consultation (neurology, neuroradiology, neurosurgery and radiation therapy) depending upon the presentation, location, size and angioarchitecture of each lesion (68 Hemorrhage, 15 seizures, ii progressive neurological deficit and 1 exophtalmus). Superselective catheteriza tion of feeding pedicles to the AVM nidus was performed with the soft microcatheters. Frequently NBCA/PANTOPAQUE were inyected using a "sandwich" technique. RESULTS: All the patients were treated by embolization, resulting in stereotactic radiation(24), stereotactic plus surgery(l), embolization cure (2 ) or improved neurological status of a progressive deficit(27); some patients continue to be treated. There were no deaths. Disabling permanent neurological deficits occured in 4 patients. CONCLUSION: Embolization is an effective therapy in a multimodality ArM treatment center.

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EMBOLIZATION OF CEREBELLAR AVM

EMERGENT ENDOVASCULAR MANAGEMENT OF CNS AVMs FALSE ANEURYSM AND HEMATOMAS R.Garcia Monaco, G.Rodesch, K.Terbrugge, P.Lasjaunias Unlt~ de Neuroradiologie Vasculalre Diagnostique et Th~rapeutlque, HSpltal Bic~tre, Unlverslt~ Paris Sud, France

M.SONOBE, S.TAKAHASHIK.and K.SUGITA Department of neurosurgery, Mito National Hospital Interventional neurovascular surgery have developed with the aids of advanced catheter system, embolic material and neuro-imaging system. In this report, successful embolization of cerebellar AVM in three patients will be mentioned. In all cases IBCA and EVAL( a new liquid embolic material presented by Dr.Taki and et al ) was used as embolic materials. A infusion catheter( Tracker 18 ) and leak balloon catheter were used as superselective micro catheters. AVM was embolized completely in the first case, however embolization were partial in another two cases. In the follow up angiographic study, AVM was thrombosed a year after embolization in the second case. In the last case, residual AVM is not thrombosed yet and additional therapy will be n e c e s s a r y in last case. Surgical removal of cerebellar AVM is difficult occasionally because of the near portion to brain stem. By the reason that the vertebral and basilar have a few branches and the distance between arterial trunks and venous sinus, Verification and superselective catheterization of feeding artery are easier in cerebellar AVM than that of other cerebral portion. It is stressed that embolization should be tried as the initial treatment for cerebellar AVM.

False aneurysms in CNS arteriovenous malformations becomes a frequent discovery particularly during the management of acute hemorrhagic episodes. Their recognition, and rapid management has shown in our experience to benefit to the immediate outcome of the hemorrhagic episode, with improved response to medical treatment, in the literature, early rebleed does not seem to be an accepted risk in ICH from AVM% however evolution of conscience disorders, and neurological morbidity seem to be modified by emergen~ embolization of the false aneurysm. They are more frequent in children than adult since both hemorrhage and neurological morbidity are significantly higher than in adults. Illustrative pediatric and adult observations will point to the technical challenges involved: rapid catheter progression, minimal volume injection, efficient and permanent occlusion. These are easily obtained with NBCA embolization, in properly trained (and available) interventional neuroradlology team. it requires perfect knowledge of the anatomy since no functional test is reliable in most of these emergent situations. The presence of a deficit does not authorize "to be proximal" since most of them will improve in few weeks. Flow control embolization, balloon or particle embolizatlon are extremely hazardous, and for us strictly contra indicated in emergency. Similarities and differences between arterial and venous false,

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220 ANGIOGRAPHIC OBLITERATION OF ARTERIOVENOUS MALFORMATIONS FOLLOWING EMBOLIZATION K.J. Gibbons, L.R. Guterman, A. Ahuja, L,N. Nopkins State University of New York at Buffalo, Department of Neurosurgery Complete obliteration of AVMs following embollzatlon is possible in selected patients. During a 2 year period 29 patients with non-dural AVMs (average 2.5 feeders per patient) underwent 44 PVA emholizatlon procedures. Complete angiographie obliteration oceured in 8 (28%), including all 6 patients with a single feeder. Delayed angiographic and/or surgical followup is available in 6 of the 8 patients. Two underwent operative excision within 3 weeks of embollzatlon; one was avascular and one repsrfused. Two non-operated patients remain with obliterated lesions at 6 and II month followup, One case with complete obliteration after a 2 stage embolization of a large 2 feeder AVM was found at i month followup to have recruited feeders from a third arterial distribution. A lesion with 2 feeders was found to have recannallzed one feeder at 3 months. Evaluation of this subgroup in whom complete anglographic obliteration was obtained suggests the following: angiographie obliteration is routinely obtained in single feeder malformations; 50% of angiographic "cures" will rapidly recannalize or recruit new feeders; and patients with multiple feeders are more likely to recannallze. Patients with one feeder and a nidus less than i centimeter have not recannalized.

CAMPRO

__SCIENTIFIC

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Scientific Session (WFITN): Percutaneous Techniques Moderators: H. Deramond, Amiens, France and M. Leonardi, Udine, Italy 04.40 p m - 04.55 pm

Percutaneous Nucleotomy G. Belloni, Bergamo, Italy

04.55 pm-05.10 pm

Vertebroplasty H. Deramond, Amiens, France

05.10 pm-05.25 pm

Facet Block K. terBrugge, Toronto, Canada

05.30 pm-06.10 pm

Scientific Papers 221-225

06.15 pm-07.15 pm (Room A)

Business Meeting WFITN

05.30 pm-06.10 pm Scientific Papers 221-225 221 Chronic low back pain: Evaluation with zygapophysial joint arthrography, discomanometry, discography, discoCT. Therapeutic issues with perentaneous nucleotomy A. Bonaf~, G. Dubois, P. Bartoli, G. Richardi, C. Manelfe, Toulouse, France 222 Neuroradiologic treatment of lumbar and cervical herniated disc G. Vogl, Innsbruck, Austria 223 Combined high flow lumbar epidural injections of saline and dilatation in the treatment of post-surgical epidural scar. Report of 21 cases E Vanneroy, E Courtheoux, X. Cornille, J. Th~ron, Caen, France

224 Treatment of extreme lateral disk herniation with automated percntaneous nucleotomy. Review of 18 cases E Vanneroy, E Courtheoux, H. Hnet, J. Th6ron, Caen, France 225 Cervical chemonueleolysis in the treatment of cervicobrachial neuralgia due to disk herniations: A study of 200 cases D. Krause, J.L. Drape, F. Jambon, D. N. Guyen, D. Maitrot, J. Tongio, Strasbourg, France

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Percutaneous Nucleotomy G. Belloni Neuroradiologia, Ospedale Riuniti di Bergamo, Italy Percutaneous nucleotomy following ONIK's technique in recent years has been accepted as a promising alternative to traditional surgery as far as limited disk protrusions are concerned. The procedure is easily performed and the rate of complications is low; the good and fair results are exceeding the 70% in the majority of the cases. In our experience based on over 500 cases treated, we can confirm these data, but at the same time we are confronted with patients who did not improve and with surgeons who do their best in order to diminish the value of the new technique. Considering the ease of the procedure and rate of success, neuroradiologists must be aware that a new approach to patient selection is mandatory. Taking into account the natural history of back pain and the relative clinical relevance of disk protrusions documented by CT and MRI examinations, percutaneous nucleotomy should be applied in my opinion to a smaller number of patients. In order to obtain more convincing results, a personality test (i.e.M.M.P.I.) as well as positive neurophysiologicai findings are required. ONIK's technique being a purely decompressive procedure, the intradiscal pressure in the horizontal and vertical position of the patient has to be recorded before the insertion

of the probe. The value of discography has still to be established in the selection o f the patients. Neuroradiologists should also have a deeper knowledge of the mechanisms involved in the genesis of back pain, bearing in mind, for instance, O'Brian's classification which recognizes three types of pain (A, B and C) in relation to the different anatomical components involved (skin, ligaments, bone, articulations and nervous structures). These structures and the related pathologies can produce more than 800 combinations which cannot be relieved only by the aspiration of a small amount of nucleous pulposus. If our aim is to obtain a wider acceptance of the promising technique introduced by ONIK, we must promote a serious comparison with the best treatments now available. To this purpose a wide clinical trial has to start with the cooperation of neurosurgeons and orthopedists randomizing patients suffering from back pain and sciatica due to posterior and intraforaminal disk protrusions. A n experience with a limited number of cases of percutaneous nucleotomy lacking serious scientific background should be discouraged.

Vertebroplasty H. Deramond, P. Galibert 2, C. Debussche 1 1Service de Radiologie A and 2Service de Neurochirurgie A, C.H.R.U. Amiens, France Built upon the hypothesis that consolidation of fragile and painful vertebrae will stop the pain, we devised a new method of percutaneous injection of methyl-methacrylate into the vertebral body under fluorscopic control. The aim of this work is: i - to prove vertebral consolidation based upon "in vitro" experimentation 2 - to describe the technique of percutaneous vertebroplasty 3 - to report the results o f vertebroplasty in various pathologies.

The third stage consists of injection of acrylic cement. A 6cc mixture is obtained by mixing 4 volumes of methyl-methacrylate powder to 1 volume (5 cc) of liquid monomer of methylmethacrylate and adding i g o f tantalum powder. When the mixture has obtained the viscosity of tooth paste, it is injected through the needle using luer-lock 2.5 ml syringes. The injection is monitored fluoroscopicaUy: at the slightest suspicion of epidural or perivertebral overflow, the injection is stopped. The procedure is best performed under local anesthesia.

III Indications and Results I Experimentation Three thoracic blocks were sampled and 2 couples of adjacent vertebral bodies were prepared in each block. One vertebral body out of 2 was injected with 3 cc of methylmethacrylate. Each vertebral body was subjected to compression testing studying 2 variables: variation of its height as a function of the force of compression. The maximum compressive strength before vertebral crush was determined for each vertebra and compared to that of the adjacent vertebral body. An effect of consolidation was obtained by the injection of methyl-methacrylate proving the increased strength of the injected vertebrae.

II Technique A 10 gauge needle is inserted in the vertebral body lesion. A biopsy, when necessary, is then performed.

The vertebroplasty has 2 objectives: consolidation and analgesic effect. The main indications are treatment of pathologies fragilizing vertebral body with or without resulting spinal pain. We have 3 major indications: vertebral hemangiomas, osteoporotic crush fracture syndrome and malignant spinal tumors.

Fertebroplasty and VertebralHemangiomas The vertebroplasty is indicated in vertebral hemangiomas accompanied by severe spinal pain and/or aggressive radiological manifestations without spinal cord or nerve compression. Vertebroplasty was carried out in 35 patients. The results were excellent in all but 2 cases with consolidation and/or analgesic effect. The analgesic effect was permanent in all cases (up to 7 years). The radiological result was stable without modification. Two accidents were noted: intercostal neuralgias healed after local infiltration.

S 178 The vertebroplasty can be associated with other therapeutic modalities: surgery and/or embolisation but we think that radiotherapy must be avoided.

Osteoporotic Vertebral Collapse Vertebral fractures, spontaneous or due to minor trauma are the classical complications of osteoporosis. Fractures are often painful, requiring analgesia and immobilisation for some weeks. The indication for vertebroplasty is then only justified when medical treatment is not effective with persistent severe pain. A vertebroplasty was carried out in 15 patients. All suffered from persisting focal spinal pain despite analgesic drugs, calcium and immobilisation for 3 weeks to 5 months. The results were excellent in all but 1 case with a long-term follow-up in 12 patients (more than 12 months). No incident was noted.

Spinal malignant tumors

35 patients were treated. The tumors were: myelomas, nonHodgkin's lymphoma and metastases. All patients had partial vertebral collapse associated with pain resistant to all treatment (radiotherapy, chemotherapy). 15 patients have noted a significant or complete relief of spinal pain with return to activities of normal living. No complications were noted after the vertebroplasty. This method is a palliative treatment and does not stop the evolution of the spinal tumor and must be associated with other therapy. Conclusion Percutaneous vertebroplasty is an original and safe method. It stops spinal pain in lesions that fragilize the vertebral body by consolidation. Three major indications must be highlighted: vertebral hemangiomas, osteoporotic vertebral crush fracture syndrome and malignant spinal tumors.

Vertebroplasty is a palliative treatment and does not stop the evolution of the spinal tumor and must be associated with other therapy.

Facet Block K.G. terBrugge Radiology, Toronto Western Hospital, Toronto, Ontario, Canada Introduction and anatomy The posterior articulations of the lumbar spine are key elements in the production of low back pain and sciatica. The facet joints are diarthrodial, gliding joints with a synovial lining. Laxity of the joint capsule allows for considerable range of movement in different directions. Synovial villae formed from recesses at the joint margins can extend between the articulating cartilages assuming the configuration of meniscoid fringes. The innervation of the facet joints is by means of medial and lateral dorsal primary rami. The dorsal primary ramus feeds into the spinal nerve at or close to the dorsal root ganglion. The dorsal ramus supplies two successive articulations. One facet joint is therefore supplied by branches from two adjoining spinal segments. Pain related to pathological conditions involving the facet joints Facet hypertrophy, focal osteophytes, rostro-caudal subluxation of facets and expansion of the facet capsule due to joint effusion can all cause direct neural compression and radicular pain. The synovial linings and joint capsule of the facet joints are richly innervated and represent an important potential source of pain. Painful stimuli are carried via medial and lateral branches of the dorsal primary ramus into the spinal nerve at the dorsal root ganglion. This pain can be referred to the lower extremities and become indistinguishable from radicular pain caused by

other processes which produce direct neurological compression of the nerve root (disc protrusion, etc.). Facet block The purpose of percutaneous stimulation of the nerve fibres in and around the facet joint capsule is to reproduce clinical symptoms. By injecting a local anaesthetic one may transiently alleviate clinical symptoms. By doing so low back pain and sciatica caused by facet pathology is distinguished from similar syndromes caused by nerve root compression. Permanent relief of symptoms can be created through surgical facet denervation. Percutaneous facet stimulation and anaesthetic block represents a valuable diagnostic and therapeutic modality available to those neuroradiologists involved with the care for patients with back pain and sciatica.

References 1. Carrera GF (1980) Lumbar facet joint injection in low back pain and sciatica. Radiology 137:665-667 2. Sheaiy CN (1975) Percutaneous radiofrequency denervation of spinal facets. J Neurosurg 43:448-451 3. Schellinger D (1987) The facet joint disorders and their role in the production of back pain and sciatica. Radiographics 7:923-944

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221 CHRONIC LOW BACK PAIN. EVALUATION WITH ZYGOAPOPHYSIAL JOINT ARTHROGRAPHY, D I ~ T R Y , DISCOGRAPHY, DISCO CT. THERAPEUTIC ISSOES WITH PEBCUTANEOUS NUCLEOTONY. A. Bonaf~, G. Dubois, P. Bartoli, G. Richardi, C. Manelfe. NeuroradiologyDepart~ent, 3 1 0 5 9 T o u l o u s e Cgdex. 51 patients (22 F, 29 M) with chronic low back pain were evaluated under local anesthesia, with zygoapophysial joint arthrography, discomanometry, discography, disco-CT in order to i) precise the anterior, posterior or combined origin of the pain, 2) correlate the degre of internal disruption of the intervertebral discs with discomanometrie data, 3) and define a rationale for treatment. 16 patients were classified as discogenic low back pain and treated (ii cases) with percutaneous nucleotomy. 15 out of 30 patients with a combined lumbalgia were treated with percutaneous nucleotomy and posterior branches thermocoagulation. 60 % of the patients who entered the study were treated ; 68 % of them achieved a good result at a six months follow-up.

222 NEURORADIOLOGIC TREATMENT OF LUMBAR AND CERVICAL HERNIA TED DISC.

G.Vogl, Institut fiir Computertomographie, Innsbruck, Austria Our first results of CT-assisted percutaneous procedures of lumbar and cervical herniated disc, which includes protruded, extruded and sequestred disc are demonstrated. CT-controlled automated percutaneous lumbar discectorny (APLD) allows placement of the tip of the nucleotome-carmuta within the dorsal third of the disc for selective reduction of protruded nucleus pulposus. From 31 patients excellent or good results were received in 28 cases (90%), in three patients APLD was combined with low-dose chemonucleolysis, in two of this APLD was performed twice. In 20 patients extruded ore sequestred herniated disc were treated percutaneous with a new CT-assisted technique, in four patients a second procedure was necessary. Excellent or good results were received in 17 (85%) patients. Cervical herniated disc was treated CT-assisted in 13 patients (at level C4-D1), five cases with chymodiactinR and eight cases with automated percutaneous cervical discectomy APCD). Excellent or good results were received in 12 (92%) cases. In conclusion, with our new CT-assisted method, cervical and lumbar herniated disc-protruded, extruded or sequestred- can be treated in an outpatient basis. With improvement of this new technique the overall result of 89% may be increased.

223

224

COMBINED HIGH FLOW LUMBAR ~ INJECTIONS OF SALINE AND DILATATION IN THE TREATMENT OF POST-SURGICAL EPIDURAL SCAR. REPORT OF 21 CASES. F. VANNEROY, F. COURTHEOUX, X. CORNILLK, J . THERON

TREATMENT OF EXTREME LATERAL DISK HERNIATION WITH AUTOMATED PERCUTANEOUS NUCLEOTOMY REVIEW OF 18 CASES F. VANNEROY, F. COURTHEOUX, H. HUET, J . THERON

C . H . R . U . d e CAEN, Avenue d e l a CSte d e N a c r e 14033 CAEN C~dex - FRANCE

D e p a r t m e n t o f R a d i o l o g y . CHU de CAEN Av. de l a c o t e de Nacre - 14033 CAEN (FRANCE)

Epidural fibrosis is one of the major causes of recurrent pain after surgery for lumbar disk herniation. No current treatment is really effective. The autbers put forward that lysis of epidural scarring could be managed by the use of high flow epidural injections of saline combined with balloon dilatation, with a catheter inserted through the sacral hiatus. 21 patients with epidural scarring without coexistent pathologic condition(recurrent disk herniation or disk fragments incorporated in scar were ruled out by CT-diskography or magnetic resonance imaging), underwent such a procedure. Informed consent was obtained in all patients. Each session of injections was repeated monthly during six months. Criteria were : subjective pain relief, reduction in pain medication and increased daily ambulation. Good and fair results were achieved in i0 of the 21 treated patien'cs (success rate = 48 %) with a follow-up of at least five months. No complication was noted. 7 .e authors set a high value on this promising technique in patients condemned until now to persistent disabilities.

PURPOSE : We p u t forward that successful results will be o b t a i n e d in foraminal and extra-foraminal lumbar disk herniations with a u t o m a t e d p e r c u t a n e o u s n u c l e o t o m y (APN). MATERIAL AND METHOD : 18 p a t i e n t s presenting with such extreme lateral disk herniation (ELDH) were t r e a t e d by APN between F e b r u a r y 1988 and J u l y 1999 a f t e r i n f o r m e d c o n s e n t . RESULTS : Very good and good achiev-ed i n 13 p a t i e n t s (success with

at

least

compIication CONCLUSION s-a-~

a

6

months

results rate :

were 72 %)

follow-up.

No

was n o t e d . :

Our

a-rid ~ f f i c i e n t

serie for

indicates treatment

of

that APN ELDH.

is

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225 CERVICAL CHEMONUCLEOLYSISIN THE TREATMENTOF CERVICOBRACHIAL NEURALGIA DUE TO DISK MERNIATIONS : A STUDYOF 200 CASES D. KRAUSE ; J. L. DRAPE ; F. JAMBOR ; D. N'GUYEN ; D. MAITROT ; J. TONGIO UNIVERSITY HOSPITALSTRASBOURG HAUTEPIERRE / FRANCE -

Purpose : To show the value of a technique (chemonucleolysis) widely used at the lumbar level but contraindicated by the pharmaceutical firm Boots-Dacour because of the spinal cord's proximity. Materials and methods : Over the past 4 years, 200 young patients (mean age = 42 years) with cervicobrachial neuralgia resisting medical treatment were treated by an intradiscal injection of chymodiactio ; this was done under neuroleptanalgesia, following diskography. Sensory, motor, or reflex deficits had been present in 40 % of cases. The pathological levels were : C6 - C7 (126) ; C5 - C6 (60) ; C4 - C5 (7) and C7 - TI (7). Postdiskography CT scans performed half an h o u r following chemonucleolysis gave proof of the torn annulus, and the location of the free fragnents. Results : the quality of the results is evidenced by the radiculalgia's regression, which was constant and durable in 80 % of patients prior to the 8th day following therapy. Failures requiring subsequent surgery were infrequent : 14/200 (7 %). Conclusion : The authors showthe value of cervical chemonucleolysis in the treatment of cervicobrachial neuralgia due to disk herniation. This alternative to disk surgery has the added advantage of preserving the intervertebral space.

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Scientific Session (WFITN): Head and Neck Moderators: B. Kendall, London, United Kingdom and P. Svendsen, G6teborg, Sweden 08.30 a m - 0 8 . 5 0 am

Endovascular Treatment of Vascular Lesions of the Head and Neck J.J. Merland, Paris, France

08.50 a m - 10.30 am

Scientific Papers 2 2 6 - 2 3 7

10.30 a m - 11.00 am

Coffee Break

08.50 am-lO.30 am Scientific Papers 226-237 226

New liquid embolization method for AVM and vascular rich tumors. Chemical embolization method using estrogen-alcohol combined with polyvinyl acetate A. Takahashi, T. Yoshimoto, Y. Fujii, N. Boku, M. Ezura, K. Mizoi, Sendal, Japan

227 Therapeutic embolization of AVM of the head and neck - 10 year experience J. Stojanovic, K. Cavka, M. Turi6, E guperina, S. ~imuni6, Zagreb, Yugoslavia 228

229

Superselective embolization of head and neck hemangiomas and AVMs in combination with YAG laser resection B. Lane, M.P. Marks, D. Apfelberg, Stanford, USA Transvenous embolization of 7 arteriovenous fistulas J.P. Pruvo, X. Leclerc, G. Soto Ares, H. Deramond, J. Clarisse, Lille, France

230 Treatment of cavernous dural arteriovenous shunts - experiences of 32 cases treated by transvenous embolization A. Takahashi, T. Yoshimoto, Y. Fujii, N. Boku, M. Ezura, K. Mizoi, Sendal, Japan 231

Embolization of head and neck cavernous and slow flow vascular malformations by direct puncture and injection

of sodium tetradecyl sulfate and microfibrillar collagen J.E. Dion, E V. Vifiuela, G.R. Duckwiter, N. Martin, P. Lylyk, A. Fox, D. Pelz, C. C. Drake, J. Girvin, G. Debrun, Los Angeles, USA

232 Endovascular therapy of carcinomas involving the skull base and the orbit T. Okuno, Tochigi, Japan 233 Functional anatomy of the thyroid arteries in bronchoesophageal pathologic conditions: Correlation with the static vascular anatomy A. Fujimura, T. Okuno, Kawasaki/Tochigi, Japan 234 Endovascular therapy for idiopathic intractable epistaxis J.J. Vitek, Birmingham, USA 235 Embolization in nasooropharyngeal bleeding - Results of 56 p a t i e n t s R. Sieckmann, A.K. Wakhloo, R.D. Hauser, H. J. Strutz, M. Schumacher, Freiburg, Germany 236 Central venous catheters for long-term chemotherapy in E. N.T. malignant tumors: Mechanical study before and after use A.L. Bailly, O. Laccourreye, J. Debout, A. Laurent, P. Gobin, J.J. Merland, Paris, France 237 Endovascular therapy of cervical lymph node metastases T. Okuno, Tochigi, Japan

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Endovascular Treatment of Vascular Lesions of the Head and Neck J.J. Merland Department of Diagnostic and Interventional Neuroradiology, H6pital Lariboisi~re, Paris, France Vascular lesions of the head and neck include congenital and acquired lesions which are located in the cervical, maxillofacial, scalp, pharyngolaryngeal and paraspinal areas. They may be isolated or multiple. The following types of vascular lesions of the head and neck are distinguished: 1. arterial stenotic lesions of dysplastic, atheromatous or other etiology 2. aneurysms and direct AV-fistulas 3. various types of vascular malformations 4. stenotic or ectatic venous abnormalities. A large number of tools for both navigation and treatment are today available. In many cases these techniques are efficient enough to be curative by themselves. AV fistulae Historically, AV fistulae have been the first type of vascular lesions of the head and neck which have been treated and cured by endovascular techniques. These include: carotid cavernous fistulae, vertebral AVF, AVF of the scalp and rarely transverse facial AVF (which have been wrongly considered as parotid AVM's in many cases). AVF in other locations of the head and neck are usually of traumatic origin. Depending on the size and the location of the fistula various embolic materials can be used such as detachable balloons, coils, cyanoacrylate, pure ethanol for direct puncture at the site of the AVE With these techniques it is usually possible to cure these AVF's very safely. Vascular malformations and hemangiomas Vascular malformations are rare and morphologically polymorph. The endovascular treatment takes a significant and very efficient role in their management:

• Infantile hemangiomas of the capillary type rarely need an endovascular treatment. Exception is in cases with cardiac insufficiency, hemangiomas located in functional areas (larynx) and hemangiomas producing enormous masses. • So-called portwine stain angiomas do not require any endovascular treatment. • Capillary venous malformations are first treated by direct puncture and injection of the sclerosing or fibrosing agent (e.g. ethibloc, ethanol, etc.). Such treatment devascularizes and shrinks the lesion, usually after several sessions of treatment. This treatment is superior to the previously performed surgical interventions, because these lesions are slowly evolutive all along the life. Postembolization surgical removal is only needed if the lesion is large or in order to correct functional and esthetic problems. AVM's represent a classical indication for endovascular treatment. Nowadays, the decision to treat AVM's must be posed carefully, because these AVM's may induce angiogenetic activity in the surrounding tissues. For that reason, we are careful with the indication for treatment in asymptomatic and nonevolutive AVM's, and especially if the angioarchitecture is made up of small shunts with associated hypervascularity in this area. If the decision for treatment is taken, then this must be a complete and curative treatment, either with liquid embolic permanent agent, or with preoperative particle embolization followed by a large surgical excision. Cystic lymphangiomas also represent a good indication for percutaneous injection of ethibloc after cyst evacuation (a systematic analysis of the liquid content of the cyst must be undertaken). Recurrence is rare with this type of treatment. Aneurysms and venous abnormalities (stenoses and ectasias) occur more rare and may be treated by an endovascular approach.

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226

227

NEWLIQUIDEMBOLIZATIONMETHODFOR AVM AND VASCULAR RICH TUMORS - CHEMICALEMBOLIZATIONMETHOD USING ESTROGEN-ALCOHOL COMBINEDWITH POLYVINYL ACETATE-

THERAPEUTIC EMBOLIZATION OF AVM OF THE HEAD AND NECK - IO-YEAR EXPERIENCE

A Takahash#, T Yoshimoto2, Y Fujii', N Boku ~, M Ezura', K Mizoi'

~Div. of Intravascular Neurosurg., 'Dept. of Neorosurg., Kohnan Hospital, q)iv. of Neurosurg., Institute of Brain Diseases, Tohoku University, Sendal, JAPAN Since 1983, we have tried to develop new liquid embolization method which fulfills following prerequisites: liquid, easy to handle, diffuse embolizing properties, no recanalization, less tissue reactions, no systemic toxicity, easy to resect. The method is composed with estrogen-alcohol (E-A) and polyvinyl acetate (PVac). E-A, conjugated estrogen dissolved in 25% ethanol, has strong chemical embolizing property obliterating capillaries to arterioles less than 100 micron. PVac, mdiopaque ethanol soluble polymer, precipitates immediately into gel obliterating larger arteriole to AV fistula. Transfemoral superselecfive embolization was performed in 54 brain AVMs, 48 meningiomas and 12 other vascular rich tumors. In brain AVMs, 15% were embolized completely, over 90% obliteration of nidus was achieved in 50%. Total obliteration rate in AVMs exclusively supplied by perforators was over 30%. Surgical resection was undertaken without difficulties in 9 cases. Other cases were/will be treated by radiosurgery. In meningiomas and tumors, low density areas were confirmed in all cases after the embolizafion. Surgical resection in 46 cases were carried out without signif'mant blood loss. Some cases showed progressing shrinkage of tumor without resection. Histological evaluation of resected lesions revealed no foreign body reactions and stable diffuse vascular obliteration. This new liquid embolization method is considered to he useful as a definitive therapy or a surgical adjunct for AVM and vascular rich

J. Stoianovid, K. (~avka, M. Tudd, F. ~uperina, S. ~imunid The work presents important features of therapeutic embolization

performed in 46 patients with the AVM of the head and neck. Eighty six percent of the cases were very complex with respect to an irrigation and extension. Combined treatment methods with unresorptive therapeutic material were applied. Plastic surgery following the last session of therapeutic emboiization definitely removed vascular malformations of the head and neck in 52% cases. According to our experience in the treatment of complex malformations better results were achived with the IBCA material In 58% cases the AVM revescularization and/or recanalization of the AVM @ccurred after the use of other therapeutic material. Success of therapeutic embolization is attributed to direct application of unresorptive therapeutic material into the AV fistula and into the AVM nidus. Our 10-year experience however shows that the presently available therapeutic material is still unoptlmal in all respects.

tumors

228

229

SUPERSELECTIVE EMBOLIZATION OF HEAD AND NECK HEMANGIOMAS AND AVM'S IN COMBINATION WITH YAG LASER RESECTION B. Lane, M.P. Marks, D. Apfelherg Stanford University Medical Center Palo Alto Medical Foundation

TRANSVENOUS FISTULAS

EMBOLIZATION

J.P. PRUVO, H. DERAMOND,

X, LECLERC, J. CLARISSE.

Hemangiomas of the head and neck require aggressive therapy when there is progressive growth, deformity, visual obstruction, dentition problems or interference with respiration or feeding. Surgical excision alone may be incomplete and complicated by the hypervascular nature of these lesions. This study evaluated presurgical embolization of hemangiomas and other vascular lesions of the face. 26 patients (age range 9 months to 49 years, mean 14 years), were seen consecutively and included in our protocol. 22 had hemangiomas, 3 arteriovenous malformations and 1 an inflammatory vascular mass. Most were located in the face, especially in the periorbital and cheek region, and other involved sites were mouth, chin, forehead, scalp, nose and neck. Diagnostic angiography was performed followed by super selective transarterial embolization. Embolization was performed through the Tracker coaxial microcatheter system (Target Therapeutics). Embolic agents included powdered GelFoam or PVA (Ivalon), suspended in dilute contrast material. Following embolization, surgery was performed usually within 24 hours utilizing the YAG laser equipped with a sapphire contact scalpel. Eighteen patients were treated with the complete protocol of embolization followed by surgery. Total removal was accomplished in the majority with minimal blood loss, ranging from 25 - 650 ml. (mean 230 ml). There were no complications from the embolization procedure. 2 minor wound healing complications occurred post surgically. All patients had an improvement in the clinical symptoms. Six patients were treated with embolization alone, and 2 patients were not embolized at the time of angiography. Super selective embolization of head and neck hemangiomas can contribute to the management of these lesions, and can reduce complications of surgical excision.

OF

G.

7 ARTERIOVENOUS

SOTO

ARES,

4 Dural fistulas involving the t r a n v s v e r s e and sigmoXd sinuses, 2 Carodid Cavernous fistulas and i vertebral arteriovenous fistula were treated using transvenous approach. All the fistulas were symptomatic a n d the t r a n s v e n o u s e m b o l i z a t i o n w a s a l w a y s performed after an arterial embolization failure. The procedure was performed from a j u g u l a r or a f e m o r a l v e i n acces. A t r a c k e r Catheter was navigated selectiv&y to the venous portion of the fistula (transverse sinus, c a v e r n o u s sinus and v e r t e b r a l vein). At t h a t level platinium microcoils were deposited. Complete angigraphic and clinical c u r e w a s a c h i e v e d for the 7 p a t i e n t s we h a d no c o m p l i c a t i o n s w i t h t h i s t e c h n i q u e . Transvenous approach s e e m s to be a g o o d a l t e r n a t i v e m e t h o d in the t r e a t m e n t of arteriovenous Fistulas with very low t e c h n i c a l risks.

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231

TREATMENT OF CAVERNOUS DURAL ARTERIOVENOUSSHUNTS EXPERIENCES OF 32 CASES TREATED BY TRANSVENOUS EMBOLIZATION A Takahashi', T Yoshimoto2, Y Fujii1, N Boku ~, M Ezura', K Mizoi~ IDly. of Intravascular Neurosurg., ~Dept. of Neurosurg., Kohnan Hospital, ~)iv. of Neurosurg., Institute of Brain Diseases, Tohoku University, Sendal, JAPAN

EMBOLIZATION OF HEAD AND NECK CAVERNOUS AND SLOW bLOW VASCULAR MALFORMATIONS BY DIRECT PUNCTURE AND INJECrION OF SODIUM TETRADECYL

Transvenous embolization for cavernous dural artedovenons shunts (CdAVS) is getting the position of one of the most effective way of treatment. From the experiences of 32 cases, indications, timing of treatment and pitfalls of this approach will be discussed. Among 38 cases of CdAVS who were considered to be treated since 1987, 37 sides in 32 cases (5 cases had bilateral lesions) were embolized transvenously as a first step of treatment. In 90% of eases, the internal carotid system contributed to the lesion. The affected cavernous sinus was catheterized either through superior ophthalmic vein (SOV) or inferior petrosal sinus (IPS) using 2.5F teflon or Tracker-18 catheter. Then, the shunting portion inside the cavernous sinus was embollzed by copper wire, platinum coils and/or silk sutures. After 35 sessions of embolization (via SOV in 16, via IPS in 18, via SOV+IPS in one session), AV shunts were completely occluded in 76% of lesions with improvement of clinical symptoms in all cases. Only one case required transarterial embolization after transvenous therapy. Concerning complications, transient cavernous sinus syndrome was observed in 6 cases, posterior ischemic optic neuropathy due to diabetes melitus and embolic cerebral infarction in 1 case each. Transvenous embolization for CdAVS is considered to be less invasive, more definitive, less complicated way compared with conventional interventional therapy. To improve clinical outcome, development of more thrombogenic materials may have an important role.

combination of sodium tetradecyl sulfate (Sotradecol) and microfibrillar collagen (Avitene). MATERIALS AND METHODS Twelve patients were treated by this technique: 9 cavernous angiomas, 1 capillary hemangiorna, and 2 AVMs, all located in the head and neck area (10 in the face and cheek, 1 in the tip), except for one located in the lumbosacral area. Sotradecol was diluted with fullstrength non-ionic contrast material to a ratio of 1:1 to 1:3; small amounts of Avitene were added to promote more rapid thrombosis of the venous pouch when normal effluent veins were seen on the direct puncture angiogram preceding embolization. In two pre-operative cases, Avitene alone mixed with contrast material was used. RESULTS In all patients, the embolization resulted in painless immediate thrombosis of the portion of the malformation where the material was

SULFATE AND MICROFIB~ COLLAGEN. JE Dion, F V Vinuela, G R Duckwiler, N Martin, P Lylyk, A Fox, D Pelz, C C Drake, J Girvin,G Dcbmn. PURPOSE To presentour experiencewith directpuncture cmbolization of slow flow and cavernous vascularmalformations using eitheror a

injected. N o evidence of recanalizationwas observed when long term follow up was available. In one patientwith a supra-orbitalskinA V M , therewas mild softtissueextravasationwhich msuhed in a O.5-1crn superficialareaof skin necrosiswhich healed spontaneously;there were otherwiseno complications. CONCLUSION Sotradccol (aloneor mLxed with Avitene)isa safeand efficient sclerosingagent for directpuncture embolizationof slow flow or cavernous vascularmalformations. In our experience,ithas proven superiorto absoluteethanolbecause itisreadilyopacifiedwith contrast materialand causes no pain upon injection.

232

233

ENDOVASCULAR THERAPY OF CARCINOMAS INVOLVIN0 THE SKULL BASE AND THE ORBIT T. 0kunno Dept. of Endovascular Therapy, Ashikaga Red Cross Hospital, Tochigi, Japan

FUNCTIONAL ANATOMY OF THE THYROID ARTERIES IN BRONCOESOPHAGEAL PATHOLOGIC CONDITIONS: CORREL A T I O N W I T H THE STATIC V A S C U L A R A N A T O M Y A. Fujimura* and T. O k u n o * * Dept. of O t o l a r y n g o l o g y , Kawasaki Municipal Ida H o s p i t a l * and Dept. of Radiology, Ashikaga Red Cross H o s p i t a l * *

I) Purpose To demonstrate

the

principle

of

the

tumor angiogenesis

theory in practical cases and to c l a r i f y the dynamic functional microvaseular anatomy of the skull base for these therapeutic anglographic protocols. 2) Methods 30 cases of nasopharyngeal carcinomas involving the skull base and the orbit had been treated exclusively by the endovascular embolizatinn therapy. According to the pre and post therapeutic imaging in formations, suitable angiographic therapeutic protocols were analyzed. To perform the endovascular cancer therapy securely, balloon occulusion t e s t s of the ICA, cranial nerve provocation t e s t s with xylocaine infusion, and stump pressure monitoring of the cancer feeding pedicles during these emb01izat ion mere fulfilled. 3) Results Partial or complete remission of the lesion have been obtained in all cases.Transient cranial neve palsy related with the end0vascular therapy were encountered in 2 cases. 4) Conclusions Endovascular therapy is powerful both in diagnostic and in therapeutic means of skull base involving carcinomas.

An a s s e s s m e n t has been made regarding the functional anatomy of the thyroidal arteries, paying attention particularly to the l a r y n g e a l artery in total 35 sides as m a t e r i a l s , i n c l u d i n g 8 cases of l a r y n g e a l cancer, 7 c a s e s of h y p o pharyngeal cancer and 5 cases of thyroidal cancer. The results were as follows; a) The lesions in w h i c h the a r t e r y was b r a n c h e d off and e s t a b l i s h e d as the s u p e r i o r laryngeal artery (SLA) into the larynx were 25 sides (73.5%), and those w h i c h were d e p i c t e d v i a the cricothyroidal artery (CTA) w i t h o u t f o r m i n g the SLA were 9 sides (26.5%). b) It was p r e s u m e d that the C T A is the m a i n alternative pathway when the SLA is underdeveloped. If 20 sides in w h i c h the C T A w a s observed in a collateral position are put together, collaterality into the larynx was found in 14 sides (70%) and that into the c o n t r a l a t e r a l system was seen in 6 sides (30%). c) C o l l a t e r a l i t y via the g l a n d u l a r a r c a d e s of the thyroidal artery o u t s i d e the larynx w e r e o b s e r v e d in 8 sides. d) C o l l a t e r a l i t y in the larynx was seen in 9 sides as classified into 4 sides between the b i l a t e r a l superior laryngeal arteries and 5 sides between the superior and inferior laryngeal arteries.

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ENDOVASCULAR THERAPY FOR IDIOPATHIC INTRACTABLE EPISTAXIS JJ Vi tek The U n i v e r s i t y o f Alabama a t Birmingham

PATIENTS

T h i r t y p a t i e n t s w i t h i n t r a c t a b l e ~diopathic e p i s t a x i s were t r e a t e d by endovascular therapy. Embolization o f the i n t e r n a l m a x i l l a r y a r t e r y c o n t r o l l e d the e p i s t a x i s in 88% o f the p a t i e n t s and the success r a t e was increased t o 97% by a d d i t i o n a l f a c i a l a r t e r y e m b o l i z a t i o n . The o n l y complication observed was t r a n s i e n t postembolization hemiparesis which occurred in one o f the t h i r t y p a t i e n t s , I n t r a c t a b l e i d i o p a t h i c e p i s t a x i s i s defined as e p i s t a x l s of unknown e t i o l o g y which is r e f r a c t o r y to nasal packing. I t is commonly t r e a t e d by surgical i n t e r v e n t i Q n w i t h l i g a t i o n o f the terminal segments o f the i n t e r n a l m a x i l l a r y a r t e r y and ethmoidal a r t e r i e s . An a l t e r n a t i v e approach is endovascular therapy. In our o p i n i o n , embolization i s a s a f e , e f f e c t i v e procedure when c a r r i e d out by a p p r o p r i a t e l y t r a i n e d personnel. In most p a t i e n t s , i t requires o n l y n e u r o l e p t a n a l g e s i a , surgery can be avoided and the d u r a t i o n o f h o s p i t a l i z a t i o n is s i g n i f i c a n t l y shortened. We recommend t h a t embolization should be adopted as the primary t r e a t ment m o d a l i t y in i d i o p a t h i c i n t r a c t a b l e e p i s t a x i s .

EMBOLIZATION IN NASOOROPHARYNGEAL BLEEDING- Results of 56 n.s~erm*, A.K:Wakhloo*,R.D.Hauser**,H,d,Strutz**,M.Schumacher*, * Sectionof Nenroradiology,Departmentof Radiology,Universityof Freiburg ** Departmentof Otorhino~aryngology,Univeraltyof Freiburg Bleedingsof the r~asooropharyngea!region,especiallyepistaxis,rely be a He-threatening event,tn this situationembolizationof branchesof the externalcarotidarteryis an effective therapyratherthanartedalligation. In the lastfiveyearswe treated56 patients(averageage48,2,rangingfrom3 to 68 years, maleJemaleratio6:5}withnasooropha~ngealbleeding, Wefoundthe followingbleedingcauses: 21 easesof epistaxJs,idio-pathicor dueto hypertension (37,5%);11 caseswithpostoperativebleeding(1g,6%),8 out of themaftertonsillectomy; 10 tumorpatiects(17,9%)including4 withangioflbromaand 6 with malignantdisease,5 casesof posttraumaticbleeding(6,9%},5 easesof angioma(6,9%),3 out of themwith av-angiomaand 2 with venoushaemangioma,3 patientswith M. Rendu~Oslerdisease(5,4%)and one casewith a paratonsll!arabscess(1,8%). The rcajodtyof embol~ationswereperformedwith 150-.300and 300-600#mPVA- parlicles. In addRiongeitoamwas usedin 8 eases.In the venoushaemangiomaethiblocwas appliedafter directpunctureof the malformation. In all casesthe bleedingwascontrolledby ernbolization.Bfeadingsfromthe ethmoidalartedes wereoperatedupon. In 37,5%of all patientswe obser,ted mildpain,localpedemaand subfebriletemperatureafterthe embollzation.Seriouscomplicationswereseenin two patientswithsystemicarlerioscle~olic diseaseinvolvingthe carotidadedes.Theydevelopedan incompleteinfarctionwith goodremissionof the neurologicaldeficit. In 9%of all casesa secondary embolizationwasrleccessary, In epistaxisin 61%onlyonesidewas examinedwithregardto the clinicalIoealisatienof bleeding,Examinationof the opositsidewas not necessary. We suggest endovascdiarembollzationproceduresin all casesof untractablebleedingof the nasooropharyngealregionratherthansurgery.Thoughin onepatienttransophthalmicernbol~zation of a facialangiomawas successful,bleedingof the elhmoidalartedesin mostcasesstill require surgery.

236

237

CENTRAL VENOUS CATHETERS FOR LONG TERM C H E M O T H E R A P Y IN E.N.T. MALIGNANT TUMORS: MECHANICAL STUDY BEFORE AND AFTER USE

ENDOVASCULAR THERAPY OF CERVICAL LYMPH NODE MgTASTASgS T. Okunno Dept. of gndovascular Therapy, Ashikaga Red Cross Hospital, Tochigi, Japan

A L Bailty 1, O L a c c o u r r e y e 2, J Debout 3, A Laurent 1, P Gobin 1, JJ Merland 1 f LNAT, PadsVII University, Claude-Bernard Research Fund, Ladboisi~re Hospital, Pads, France 2 ENT and Cervico-Facial Surgery Department, Laennec Hospital, Paris, France 3Department of Mechanical Engineering, University of Technology Compit~gne, France To v e r i f y the i n t e g r i t y of c a t h e t e r s m e c h a n i c a l performance, while exposed to aggressive c h e m o t h e r a p y a g e n t s for several months, w e studied the mechanical characteristics of 6 different types of catheters from various manufacturers and base material (mainly polyurethan and silicon), implanted subcutaneously (subclavian, jugular or axillar vein). 2 groups have been defined: 50 implanted catheters, compared with control catheters of the same material and brand, 20 catheters from which a small part was taken as their own control. The properties studied were: the tensile strength of ruptur e , resistance to kinking, and surface aspect (light microscopy and S.E.M.) before use, and after they w e r e r e m o v e d from the patients at the end of the c h e m o t h e r a p y c o u r s e or if rupture of the c a t h e t e r occured.The chemotherapy, for E.N.T malignant epidermo'fd tumors, w a s administered c o n t i n u o u s l y , before, around or after surgery, and consisted of 6 various antimitotic drugs combined in several protocols. Mean duration was 6 months (3 months-2 years). Statistical analysis w a s performed with Deltasoft P C S M ® on IBM PC ®. T h e a l t e r a t i o n s of m e c h a n i c a l p e r f o r m a n c e s a r e described by group of catheters and in function of the chemotherapy applied and its duration.

t ) Purpose To demonstrate the p r i n c i p l e of the tumor angiogenesis theory ;n p r a c t i c a l cases and to c l a r i f y the dynamic functional microvascular anatomy of the c e r v i c a l m e t a s t a t i c lymph nodes for these therapeutic angiographic protocols. 2) Methods 35 cases of c e r v i c a l lymph node metastases from various primary o r i g i n s had been t r e a t e d e x c l u s i v e l y by the endovascular embolizatlon therapy. According to the pro and post t h e r a p e u t i c imaging informations, s u i t a b l e angiographic t he ra pe ut i c protocols were analyzed. To clarify the h i s t o p a t h o l o g i c a l e f f e c t s of endovascular cancer therapy, post - t h e r a p e u t i c specimens of c e r v i c a l m e t a s t a t i c lymph nodes a f t e r neck d i s s e c t i o n s were a l s o examined in some cases. 3) Results P a r t i a l or complete remission of the lesion have been obtained in a l l cases.No neurological d e f i c i t s r e l a t e d with the endovascular therapy were encountered. 4) Conclusions Endovascular cancer therapy under suitable anglographiC protocols is powerful both in diagnostic and in therapeutic means of cervical lymph node metastases.

S 186

Scientific Session (WFITN): Spinal-Vascular Moderators: J.J. Merland, Paris, France and P. Lasjaunias, Paris, France 11.00 a m - 11.20 am

Vascular Anatomy of the Spinal Cord A. Thron, Aachen, Germany

11.20 a m - 11.40 am

Endovascular Treatment of Spinal Cord AVMs A. Berenstein, New York, USA

11.40 a m - 12.05 pm

Scientific Papers 238-241

11.40 am-12.05 pm Scientific Papers 238-241 238 Result of endovaseular treatment with tissue adhesives in 27 patients with spinal dural arteriovenous fistula

240 Angiography in diagnostic, treatment and follow-up of the patients with spinal region tumors

13. I. Kim, I.S. Choi, A. Berenstein, Seoul, Korea/New York, USA

J. Stojanovi6, K. Cavka, A. Kamler, G. Buljat, E ~uperina, E Kne~evi6, B. Radanovid, Zagreb, Yugoslavia

239 Aneurysms of spinal arteries associated with intramedullary arteriovenous malformations: Results of AVM endovaseular treatment and hemodynamic considerations A. Biondi, .I.E. Hodes, D. Reizine, A. Aymard, J.J. Merland, Paris, France

241

Endovascular treatment of vertebral arterio-venous fistulas: 46 cases R. Beaujeux, M.C. Rich6, A. Aymard, D. Reizine, P. Gobin, A. Casasco, V. Vasquez, D. Herbreteau, A. Laurent, C. Laurian, J.J. Merland, Paris, France

S 187

Vascular Anatomy of the Spinal Cord A. Thron Department of Neuroradiology, Medical Faculty, Technical University of Aachen, Germany Demonstration of the angioarchitecture of the spinal cord in man is based on findings of in vivo angiography and of a radioanatomical study of postmortally injected specimens. In the first part of this presentation, a description of the arterial supply (superficial and intrinsic arteries) will be given. The regional variability of radicular feeders, of the longitudinal arterial trunks and of the superficial anastomotic circles and networks will be shown. These radiologieal findings correspond well to the early anatomical descriptions given by Adamkiewicz and Kadyi at the end of the last century. They constitute the basis for our understanding of spinal cord blood flow. The concept of "circulatory partial systems" (Adamkiewicz) or the "poor supply" of the upper thoracic region, leading to the hypothesis of marginal zones (Ziilch) will be critically evaluated. The intrinsic spinal arteries (central and peripheral system) and their territories of supply are demonstrated on microradiographs in different planes. Anastomoses can be shown between central arteries at the anterior median fissure (not within the spinal cord substance) and rarely between central arteries and superficial vessels. The regional variability of arterial supply conditions and of the intrinsic territories corespond to locally variable blood requirements.

The second part of the presentation deals with the less well known spinal cord veins. The intrinsic drainage pattern of the spinal cord parenchyma can be characterized as a radially symmetric, largely horizontally oriented system. Not until the level of the spinal pia mater is blood accumulated in larger longitudinal anastomoses, of which the anterior and the posterior median spinal veins are the most constant vessels with greatest caliber. Transmedullary venous anastomoses of considerable caliber, connecting the median main veins are quite common. They may be interpreted as an arrangement to equalize venous pressure. Drainage routes of the superficial system run towards the inner extradural vertebral venous plexus via the anterior and posterior radicular veins. Their number has been overestimated in the past. A topic of special interest is the reflux-impeding mechanism, existing in the dural segment of radicular veins. In agreement with Tadie et al. we have been able to demonstrate by histological serial sections and microangiograms that specific arrangements of this transdural vein passage functionally operate like a valve mechanism. A slit type in 60% and a bulging or glomus type in 35% of cases can be differentiated as main configurations.

Endovascular Treatment of Spinal Cord AVMs A. Berenstein New York University Medical Center, New York, USA The goal of endovascular treatment of spinal cord AVMs (SCAVMs) is complete occlusion of the nidus of a vascular malformation or the neovascularity of a tumor, preserving vascular supply to normal territory. To reach this goal, one should inject the embolic material as close as possible to the nidus or neovascularity, and it should be resistant to reabsorption or recanalization. In the last 20 years several embolic materials and catheter systems have been developed for various applications. SCAVMs can be divided into three groups: true SCAVMs, spinal dural arteriovenous fistulas (SDAVFs) and metameric AVMs. The incidence of spinal cord vascular malformation in relationship to the various types of space-occupying lesions ranges from 2 % - 4 % . SCAVMs are supplied by the anterior and/or posterior spinal arteries. They may be located totally in the spinal cord, partially in the spinal cord, or totally on the surface of the cord. The mean age of presentation is in the mid-twenties. However, in more than 50% of patients, the symptoms are present prior to the age of 16. The most common clinical presentation is hemorrhage, subarachnoid or in the spinal cord itself (hematomyelia). Other presenting neurologic symptoms are root or back pain (i 5070-20%), motor weakness (33%), and numbness. Impotence and bowel and bladder dysfunction are often associated. Spinal deformity, kyphosis, and scoliosis may be seen in patients with SCAVMs. Once hemorrhage occurs, the recurrence

rate within the first month is nearly 10%0 and within 1 year 40%. The mortality directly related to hemorrhage from the SCAVM is at least 17.6%. These malformations can occur at any level of the spinal cord; however, more often they appear in the cervical area (cervical enlargement) and near the conus medullaris. There are, in principle, multiple feeders to the malformation with high-flow AV shunting, via the anterior spinal and/or posterior spinal arteries. The feeding radiculomedullary arteries are enlarged in caliber and may have a tortuous course, unlike the straight course of the normal spinal arteries. Depending on the situation of the nidus, either anterior or posterior spinal arteries will dominate the supply. The size of the nidus and presence of AV fistula govern the caliber of the feeders. One may find aneurysmal dilatation (pseudoectasia) of the feeding artery at the nidus or at the draining veins, which causes widening of the spinal cord, mimicking a tumor and displacing the spinal arteries. The draining veins are usually multiple and dilated, often extending the whole length of the spinal cord. The anterior and posterior spinal veins can be easily identified in the lateral view of the angiogram. There are anastomoses between the anterior and posterior spinal veins, frequently perispinal (coronary venous plexus). In cervical AVMs, the veins may drain intracranially into the mesencephalic veins, which can cause intracranial subarachnoid hemorrhage.

S 188 The development of microsurgical techniques and precise presurgical evaluation, including high-quality spinal angiography, have improved the results of the surgical excision of the SCAVMs. However, persons with excisions of deeply situated intramedullary AVMs still have high morbidity. Endovascular embolization has become a highly competitive mode of treatment in the last 15 years. Embolization of deep seated AVMs can achieve complete cure with less morbidity than surgical excision. Preoperative embolization facilitates favorable surgical results. In some instances, partial embolization improves or stabilizes neurological deficits. The goal of embolization is complete occlusion of the nidus of the malformation and feeding arteries, preserving the vascular supply to the normal spinal cord. Historically, gelfoam pellets and silastic spheres were choices of embolic materials. The gelfoam pieces are difficult to direct precisely into the malformation, and they will be reabsorbed, dissolved in 1 - 2

weeks; thus recanalization of the occluded segment occurs in general. In the last 10 years isobutyl-2-cyanoacrylate (IBCA) and more recently n-butyl-cyanoacrylate (NBCA) has been accepted as one of the choices of embolic materials that can produce a complete cast of the nidus without recanalization. Safety of IBCA or NBCA embolization is improved with the new softer microcatheters that can be introduced even into the anterior spinal artery close to the nidus. To evaluate functional importance of a particular vessel, one performs a provocative test utilizing 50 to 75 mg of sodium amytal prior to the injection of embolic material. The test is correlated clinically and ,with SEP monitoring. When surgical excision is planned, preoperative embolization can be carried out relatively safely. Polyvinyl alcohol (PVA) foam of various sizes can be injected by flow direction. PVA is small enough to penetrate and occlude the nidus.

S 189

238

239

R E S U L T OF E N D O V A S C U L A R T R E A T M E N T WITH TISSUE A D H E S I V E S IN 27 PATIENTS WITH SPINAL DURAL A R T E R I O V E N O U S FISTULA DI Kim =, IS Choi ~, A Berenstein' ~Section of Interventional Neuroradlology, Department of Radiology, School of Medicine, New York University, New York, USA 2Department of Diagnostic Radiology, School of Medicine, Yonsei University, Seoul, Korea

ANEURYSMS OF SPINAL ARTERIES ASSOCIATED WITH INT~DULLARY ARTERIOVENOUS MALFORMATIONS : RESULTS OF AVM ENDOVASCULAR TREATMENT AND HEMODYNAMIC CONSIDERATIONS

A. Biondi, JE Hodes, D Reizine, A. Aymard, JJ M e r l a n d Department of Neuroradiology and Therapeutic Angiography, University of Paris VII, Lariboisiere Hospital, Paris

Authors review the twenty seven patients with spinal DAVFs who were managed by endovascular embolization technique with tissue adhesives. Most of the patients presented with a slowly progressive sensory and motor weakness of lower extremities and sphincter dysfunction. Patients' neurologic deficits improved following initial procedures but it was not sustained in 10 instances. Follow-up angiography revealed re-establishment of the shunt in 7 patients, was followed by repeat embolization. Endovascular technique can ultimately achieve the anatomical cure in twenty five patients, but combined surgical extirpation was needed in two patients with recanalization of fistulas. Partial but significant recovery occurred in most patients. Our experience indicates that, if it is performed properly, an embolization technique can alone achieve the permanent therapeutic goal.

Fourteen patients with i n t r a m e d u l l a r y AVMs and an associated spinal aneurysm (SA) underwent endovascular treatment with particles of their AVM. Embolization sessions ranged from one to 14 (mean five) in each patient, The purpose of this study was to evaluate the changes occurring in SA size related to modification of the endovascularly treated AVM, In our series a group of SAs decreased in size or disappeared after AVM reduction or cure and increased or reccurred after AVM recanalization. A second group of SA remained unchanged despite AVM changes (6/7 of these were in patients with metameric angiomatosis). Results in the first group lend support to the hemodynamic theory of associated aneurysm formation. On the other hand, aneurysms that remained unchanged probably are not AVM flow related and could be an expression of an extensive vascular disorder such as m e t a m e r i c angiomatosis. However, h e m o d y n a m i c and developmental factors could be concurrent,

240

241

ANGIOGRAPHY IN DIAGNOSTIC, TREATMENT AND FOLLOW

E N D O V A S C U L A R T R E A T M E N T OF V E R T E B R A L ARTERIO-VENOUS FISTULAS : 46 CASES. R Beaujeux, MC Riche, A Aymard, D Reizine, P Gobin, A

-UP OF THE PATENTS WITH SPINAL REGION TUMORS J. Stojanovid, K. C:avka, A. Kamier, G. Buljat, F. ~uperina F. Kne~evi6, B. Radanovi6 We are presenting herewith the important features of therapeutic angiography appiied in 32 patients with spinal and/or paraspJnai tumorous process of which 8 were primary malignant, 18 secondary maiignant and 6 benign. All patients were treated with the nonresorptive therapeutic material. Some were operated, irradiated and/or subjected to chemotherapy.

The success of the therapeutic emboiization is in the direct application of the nonresorptive material and/or chemoembolizing agents directly into the site of tumor so as to achieve a protracted contact of the drug with the tumorous tissue. The treatment protocol in such instances was directiy related t6 the biology of the pathological process, its hemodynamic activity, in/operability, extensiveness, dissemination and further treatment. Our method is being more and more often applied in the treatment of such tumors.

Casasco, V Vasquez, D Herbreteau, A Laurent, C Laurian, JJ Merland

Dpt of InterventionalNeuroradiology,Ladboisi~reHospital,Pads, France To investigate the efficacy of endovascular treatment of vertebral arteriovenous fistulas (AVF) we retrospectively reviewed the cases treated at our institution over the past twelve years. The clinical and angiographic features of 45 patients with 46 vertebral AVF were reviewed. Balloon embolization procedures were used in most of the patients treated. Presentation was varied: 46% bruit, vertigo 13%, neurological deficit 7%, pain in 4%. Thirty percent were a s y m p t o m a t i c and d i s c o v e r e d on routine clinical examination. The etiology was traumatic in 41% o f the patients and spontaneous in the remaining 59%. The fistula was found to be at C t - C 2 in 46%, C2-C5 in 28%, and below C5 in 26%. Embolization was performed with latex contrast filled balloons in the majority of the fistulas. Endovascular therapy results were successful in 82%, partial in 8%, and failed in t 0 % . Only three complications occurred: three clinically asymptomatic occlusions of the vertebral artenL Endovascular balloon treatment of vertebral AVFs is effective in occluding the shunt. It also avoids general anesthesia, surgical procedure, and has minimal morbidity. It is the method of choice for these lesions.

S 190

Scientific Session (WFITN): Miscellaneous Moderators: I.S. Choi, New York, USA and G. Debrun, Baltimore, USA

12.10 p m - 12.55 pm

Scientific Papers 242-246

12.55 pm

Closing Remarks

12.10 pm-12.55 pm Scientific Papers 242-246 242 Anatomic landmarks in pre-therapeutic evaluation

245

H. Alvarez, I. Iizuka, P. Lasjaunias, Paris, France

Hydrogel, potential new material for endovascular treatment of aneurysm and fistulae

B.A. Mehta, W.P. Sanders, T.H. Burke, M. Dujovny, Detroit, USA

243 Major complications in 670 interventional neuroradiological procedures

I. Nakahara, J. Pile-Spellman, L. Hacein-Bey, R.M. Crowell, D. Gress, Boston, USA 244 Spontaneous revascularization of the carotid siphon in follow-up of internal carotid occlusions

V. Vazques, J.E. Hodes, A. Aymad, Y.P. Gobin, A. Casasco, D. Reizine, J.J. Merland, Paris, France

246

Superselective intraarterial chemotherapy for treatment of malignant brain tumors - Comparative study with conventional chemotherapy

A. Hyodo, Y. Yoshi, H. Tsurushima, Y. Matsumaru, K. Tsuboi, T. Nose, Tsukuba, Japan

S 191

242

243

ANATOMIC LANDMARKS IN PRE-THERAPEUTIC EVALUATION H.Alvarez, I.Iizuka, P.Lasjaunias Unit~ de Neuroradiologie Vasculaire Diagnostique et Th~rapeutique, H~pital Bic~ire, Universit~ Paris Sud, France

MAJOR C O - - C A T I O N S IN 670 INT~VENTIONAL NEURORADIOLOGICAL PROCEDURES I. Nakahara, J. Pile-Spellman, L. Hacein-Bey, R. M. Crowell, D. Cress

Department of Radiology, Neurosurgery, and Neurology, Massachusetts General Hospital, Boston, Massachusetts, U.S.A.

Pre therapeutic angiographic analysis, among other informations, must provide technical features related to hazards of endovascular techniques. It is clearly demonstrated that embolic agents strictly located in an AVM nidus, AVF junction or a tumor bed only carry hazards related to the type of agent used and target reactivity. Sparing normal tissue with any embolic material and a non reactive target cannot give symptoms. Therefore in any location and angioarchitecture, one must determine an ideal point for a given embolic agent delivery and a security point where the embolic material can still be used safely with a similar or acceptable clinical efficiency. The capacity of pointing to these anatc~nical landmarks reflect the experience of the neuroangiographer and remove superstition and fatalism from our practice. Therefore ophtalmic, anterior spinal or anterio choroidal arteries e~bolization with liquid agents can be safe if one knows perfectly this anatc~y its varaition and traps. Thereafter only a larger amount of patient can safety benefit from endovascular techniques. Unpredicted complications in these situation always reflect either unsufficient theoritical (anatomy) training or urm~stered skills, and sometime both. The concept of "safer embolic agents" is unacceptable since safety almost exclusively leans on the specialist side in relation to its competence.

Purpose: Between July 1988 and April 1991, we have performed 670 interventional neuroradiological procedures using a variety of techniques. We report our major complications with these procedures and analyze their etiology. M a t e r i a l s and Methods: Clinical and radiological assessment was made in patients with major complications during this period. Major complications consisted of permanent major neurological deficits or life-threatening events which required emergent therapy. Results: Major complications were noted in 20 patients (3%) during this period. Death occurred in 7 patients (1%), and permanent major deficits were observed in 11 patients (2%); of this group, 3 had cranial nerve palsies and 8 had a variety of cerebral hemisphere or spinal cord dysfunctions. 2 patients had lifethreatening events which resolved without any residual deficits. 11 of these complications were attributed to technical problems including materials, catheterization, provocative testing, and radiological evaluation. Management of coagulation status (heparinization) was involved in 5 patients. Intra- or postprocedural monitoring was related to the events in 4 patients. Conclusion: We consider that meticulous ICU monitoring of neurological findings and systemic functions including cardiovascular and coagulation parameters are essential to avoid these major complications, as well as the refinement of interventional neuroradiological techniques.

244

245

Spontaneous R e v a s c u l a r i z a t i o n of t h e C a r o t i d S i p h o n in F o l l o w - u p of Internal Carotid Occlusions V Vazquez, JE Hodes, A Aymard, YP Gobin, A Casasco, D Reizine, JJ Merland. Ladboisi~re Hospital, Paris

We report the occurrence of spontaneous collateral revascularization of endovascularly o(~cluded carotid arteries. 60 patients were treated by endovascular carotid occlusion for carotid-cavernous fistulas (CCF) and carotid aneurysms between 1980 and 1989. All patients were followed with consecutive clinical and radiographic studies at 3,6, 12, and 24 months. Results: 5/60 (2 CCF, 3 aneurysms) developed progressive revascularizatien of the carotid siphon through the artery of the foramen rotund.um, vidian artery~ accessory meningeal and middle meningeal arteries coming from the external carotid artery. This revascularization completely filled the distal carotid artery anterograde, always filling the portion of the carotid artery that gave rise to the CCF or aneurysm, without recurrence of the pathology. No distal embotization occured in. follow-up and no patient,had recurrence of their presenting pathology. Carotid occlusion may be followed by spontaneous collateral revascularization of the distal carotid artery. While other authors have discussed revascularization via the ophthalmic artery, this is the first demonstration of complete revascularization of the carotid siphon.

HYDROGEL, POTENTIAL NEW MATERIAL FOR E N D O V A S C U L A R T R E A T M E N T OF A N E U R Y S M A N D FISTULAE B A M e h t a , W P S a n d e r s , T H Burke, M D u j o v n y Henry Ford Hospital, Detroit, Michigan PURPOSE: E v a l u a t i o n o f u s e of a h y d r o g e l " s t e n t " f o r t r e a t m e n t of a n e u r y s m s a n d f i s t u l a e in an a n i m a l m o d e l . MATERIALS & METHODS: Side to side aortocaval fistulae were microsurgically created in i0 rats. A l l i0 f i s t u l a e w e r e t r e a t e d b y p l a c e m e n t of a s m a l l t u b u l a r h y d r o p h i l i c s t e n t in t h e IVC or a o r t a a c r o s s t h e f i s t u l a site. The material swells with water absorption, maintaining a patent vessel lumen, w i t h c o m p l e t e f i s t u l a c l o s u r e . RESULTS: A l l I0 f i s t u l a e w e r e e f f e c t i v e l y c l o s e d a f t e r p l a c e m e n t of t h e o c c l u s i v e h y d r o p h i l i c stent. CONCLUSION: Currently endovascular treatment of cavernous carotid aneurysms and f i s t u l a e r e l i e s o n t h e p l a c e m e n t of detachable balloons within the lesion to p r e s e r v e t h e p a r e n t v e s s e l , o r s i m p l y to o c c l u d e t h e a r t e r y itself. Complication of r e - o p e n i n g o f t h e lesion, b a l l o o n m i g r a t i o n a n d t h r o m b o - e m b o l i are w e l l known. Hydrogel s t e n t s w e r e u s e d t o c l o s e A V f i s t u l a e in t h e rat model. T h e i n i t i a l s m a l l s i z e of t h e devices suggest that they may be used to t r e a t l e s i o n s s u c h as c a v e r n o u s c a r o t i d fistulae, cavernous carotid aneurysms, or s u c h l e s i o n s in o t h e r v e s s e l s t h a t l a c k l o c a l "perforating" branches which may be occluded by stent placement. F u r t h e r a n i m a l w o r k is ongoing , using larger animal models and other vessels.

S 192

246 SUPE~ELIL~TIVE INTR~RTF~IAL ~I~OTI~R~Y FOR TI~ATMF/ffOF HALI(~ANT B~IN TU~I~

-COHP~ATI~ STUDY WITH CO~ENTIONAL I~]~TF~IAL (H~O~HE~PYA.Hyedo, Y.Yeshi, H.Tstrushim. Y.~ts~ar~, K.Tsuboi. T.Nose I)~ar~ent of Neurosurgery, University of Tsukube • Tsukub~ Japan From December1985 till March 1991, 41 patients of malignant brain tumors received 55 courses of Nimustine hydrechloride (ACNU)or cisplatin administered by supraophthalmio interval carotid, middle cecebral, anterior cerebral or posterior cerebral artery infusions. Superseiective catheterizatiou was carried out under I)Shcontrol, using 2. 7-Frsnch Tracker-18 catheter through 7-French guiding catheter transfemoraly. AC~ was administered by Tracker-18 catheter at a dose of 0.7-1.0 mg/lig.In carting out the 55 superselective infusion, only two minor complicationsas a transient bemiI~aresisand a trap~ient conscioanessdisturbanceoocurrecL~ intratumoral conceqtrationof the ~ was assemedby the calculation from the distributiem of contrast mediumon DSA.In order to evaluatethe effeVcivenessof superselective intraarterial ([A) chemotherapy,we ~ a r e d the cases of maliguast gliomas which were treated by superselective Ih chemotherapy in this ~ r t wi~ those treated by cenventiom[ Ih chemotherapy esriier. To su~arise our study, the estimated intratumoral concentration of the superselective injection was 2.36 times higher than that obtained by conventional intracarotid injection; at the same t i m ~ dose of AC~ was significantly lower.Comparingsuperselective and conventional IA chemotherspyof malignant gliomB, the reduction rate of the tumor was statistically significantly higher, In conclusion, superselective Ih chemotherapyof malignant brain tu~ors is a relatively safe and effective treatment comparedwith conventioml Ih chemotherapy.

Scientific Posters

S 194

Posters ICHNR Poster 1 A SWALLOW

Poster 2 ASSESSMENT

CLINIC

-

WHY AND HOW

MALIGNANT FIBROUS HISTIOCYTOMA OF TEMPORAL BONE H. S. J h a v e r i ; P. S. R o l a n d ; C. L. W h i t e , III The University of T e x a s S o u t h w e s t e r n Medical C e n t e r at D a l l a s , T e x a s , U S A

F.R.WRIGHT The

ULSTER

HOSPITAL,Oumdomald,BELFAST.

T h i s ~S m i n u t e v i d e o p r o g r a m m e highlights the n u m b s r oF p a t i e m t s w i t h a w i d e r s m g e oF d i s o r d e r s in w h o m s d y n s m i c v i d e o f f l u o r o s c o p i c assessmemt off the

oral~

pharyngeal

and

cervical

oesophe~eel

p h a s e s oF s w a l l o w i n g is i n d i c a t e d . T h e n e e d is probably greeter them has beam reeliaad to d a t e , It h a s b e e n s h o w n t h a t et l e a s t 4 0 % o~ s t r o k e patients) in h o a p i t s l o r et h o m e ~ w i l l h a v e e s w a l l o w i n s p r o b l e m and a l m o s t h a l f off t h e s e w i l l be s i l e n t l y a s p i r a t i n g , having lost their cough reFlax.(Gordon et al ~$87) T h i s n u m b e r c o u l d be 5 C O e a c h y s s r im N o r t h e r n Ireland. (Ropulstion ~ million] There sre also many patlants with other meuralogical camditions) aemgenitsl smd acquired or w h o h a v e h a d m a j o r t h r o a t or n e c k s u r g e r y w h o will have similar swallowing diFFiculties. All these meed assessing emd ssme require training or t h e r a p y in o r d e r to r e d u c e t h e r i a k oF a s p i r a t i o n pneumonia e n d to h e l p m a n a g e t h e i r m u t r i t i c n and hydretiom. We i l l u s t r a t e bow e Swallow Assessment Clinle~ o p e r a t e d by e R a d i o l o g i s t ) a Speech Therapist and a Dietitian) can setisffy.thls need. Our videoFluoroscopic technique~ usim s a modified barium swallow, is d e m o m s t r a t e d w i t h e v a r i e t y af c a s e s ffrom the 3 0 0 + p a t i e n t s we h a v e s e e n s i n c e qS86. ReF. G o r d o m C et el: D y s p h a g i s in a c u t e stroke. BMJ ~$5:4~-4~4) 1987. O t h e r rsffersmces a r e a l s o s v s i l s b l e .

Poster 4

Poster 3 EXTERNAL AUDITORY n o r m a l a n d patl~ological K MARSOT

PURPOSE: A r a r e c a s e of m u l t i p l e cranial nerve palsies due to malignant fibrous histiocytoma (MFH) of t h e p e t r o u s p a r t of t h e t e m p o r a l b o n e extending into the cavernous sinus with angiographic, CT, a n d M R I c h a n g e s is p r e s e n t e d . METHOD: A 39 y e a r - o l d , right-handed man presented with headache for 3 months and acute diplopia. Clinical examination revealed left ptosis, 6th nerve palsy, facial weakness, h e a r i n g loss, and Horner's S y n d r o m e o n t h e left. Audiometric evaluation revealed a left-sided 40dB conductive hearing loss. T h e CT r e v e a l e d a l a r g e d e s t r u c t i v e lesion in t h e c a r o t i d c a n a l r e g i o n at t h e t i p of t h e petrous temporal bone extending into the ipsilateral cavernous sinus. Gadolinium enhanced MRI revealed a mass in the left cavernous sinus. Arteriography revealed occlusion of t h e i n t e r n a l carotid artery from the bulb to the supraclinoid portion. Exploration r e v e a l e d a f l e s h y t u m o r m e d i a l to and infiltrating the internal carotid artery, which was filled with neoplasm. RESULTS: Pathological examination disclosed a spindle cell neoplasm consistent with MFH. CONCLUSION: Differential diagnosis of a m a s s in t h e p e t r o u s a p e x of t h e t e m p o r a l b o n e s h o u l d inc l u d e u n u s u a l l e s i o n s s u c h as M F H . Radiological evidence of a r t e r i a l invesion strongly suggests malignancy.

CANAL: findings

DUPUCH , T YRIBOZ MM J VIGNAUD , B MEYER

~¢AU~TI~ C~ ~r0#"~ATI~ (Xr,~CATIOtCS ~" PAT~I~TS ~ N ~ R rm~k~TS (CI) BY COMPLEX F~TIS{ TCMOG~%~BY (Ca~)

_

FIRAT

,

P U R P O S E : To illustrate v a l u e of CT and MR in diagnosis and s p r e a d of CAE's d i s e a s e s . M A T e R I A L S AND Ag~le~O/~; = W e r e t r o s p e c t i v e l y a n a l y s e d 50 p a t i e n t s w i t h diseases of CAE explored b y high resolution CT ,and MR ( 1 5 / 50) (TI and T2 W.I.). R I I ~ U L T S : C A E ' ~ e m b r y o l o g i c a l origin ( I arch ) , limits and usual p a t h w a y s of spread( SANTORINI fissures , p e t r o t y m p a n a l scissures) e x p l a i n e d lesions uncountered in CAE and their p a t h w a y s of spread .: malignant external otitis ( 15 ) severe acute otitis ( 2 ) c h o l e s t e a t o m a s (3) glandular turnouts ( 3 ) e p i t h e l i o m a s (3) angiosarcomas (2) r h a b d o m y o s a r c o m a s (2) first branchial cyst (I) stenosis or a t r e s i a ( 3 ) .Diagnosis w a s a s s u m e d b y CT demonstrating soft tissue m a s s , zones of cortical bone e r o s i o n s ( 1 3 / 1 5 ) .Spread of the d i s e a s e w a s b e t t e r d e l i n e a t e d b y MR t h a n CT e s p e c i a l l y for skull b a s e e x t e n s i o n and cranial n e r v e i n v o l v e m e n t . T e m p o r o mandibular joint i n v o l v e m e n t w i t h extension into parotid o r / a n d masticator spaces w a s as w e l l detected b y CT than MR.UON(TLUSION : Spread of CAE's diseases into parotid gland, infra temporal fossa, skull base ,middle ear , mastoid bone explain the impact of imaging studies .If CT remains the first and best procedure for diagnosis, MR despite its cost appears a good procedure to depict exact anatomic spread guiding therapeutic procedure .

iA.n. Q~-2~ti, E. Banter, R. iaszig, Ph. Na~riclx, B. D. Bertmar, A: Galarski, Departa~mts of Diagnostic i~mifologyI am7 E.N. T, ~ c a / ~c8ooI of E~mover, F e d ~ / R e ; ~ / / c of C-atm~y liras it is o0acievable that the number and depth of the inserted electrodes (~) of CI may have some effects ca the patiests performanee and s p e e ~ t m d e r s t a ~ . Our study was desired to evaiuate the n~m~er of intra- - ~ e x t r a - - e a r ES ~ to s t ~ the discrepancy between the qpe/'ative notes and the t ~ c fin-

B~TEPJ2~ & I ~ : Of 166 patieats who underwent cochlear implantati~a usiso 22 "channel CI (~UCL~JS) at the department of E.N.T of Fedical School of B;mnover (F.R.G), 23 patients (13 male, 10 female) were z - ~ a ~ evaltmted for their atTay pesiti~l by Cn~. Different z-ddiogl~hic projecticos ~ ima~im7 te~miqu~ were first tested o~ htlm%n skull phantom with was implanted with CI free I ~ g . The ~ T (SIF~¢S) was used for (~T. U S ~ tO~OQl~d~y We c ~ t e d the n ~ _ r of int~- ~ extra-eocl~le~" ES. REVOLTS: 17 patieats I ~ ES outside the fenes~ti~,, in II patients we o~mted more extra-cochlear ~ ~y tomogra~hy than were mentioaed in ~ e oDeratiou re~orts, of ~ich 7 patients had the active ES either in the ~ c cavity or in the O/'ill-~ hole or in the ~ part of the coub]ea near the ro~m~ w ~ . Five out of 7 these patients ~ kinki~ of the array and o~e d e ~ strated c~ression of two apical ES. A ~ifferanoe of more ~ 6 ~ significant o0r~alated with disturbin~ sensations caused by CI. In 6 patients z~iographic findings w e ~ ceasisteat w~th a COmplete ~sertica. ~FmT~RY: Onr study de~x~tt~ted tlet dislocatioa of the array outside the cochlea into the t l ~ c cavity resulted in disbmb'n~ s~satio~s ~ich h M to be cont~lled by s w i t d ~ of the affected ~ . Array disl0catiou is not ~)~ and can be avoided by our new fixati(m teel~que. A direct ~stop. tomography 0cmbined with an overview in f~x~tal tl'-~m~orbit~ projectioa seems to he necess~Tf for the follow up of the CI-patiants.

S 195

Poster 5

Poster 6

PHASE Ill MULTI CENTER TRIAL OF A NON-IONIC G A D O L I N I U M C I t E L A T E [ G A D O T E R I D O L ] 1N P A T I E N T S WITH SUSPECTED HEAD AND NECK PATHOLOGY G . H . Z o a r s k i , R.B. L u f k i n , W . G . B r a d l e y , M. C a r v l i n , A.F. F l a n d e r s , D.R. G a l e , S.H. H a r m s , V . H . H a u g h t o n , S.Joy, E. K a n a l , L. R o s a , V. R u n g e , J.M. T a l b o t , W . T . Y u h . U n i v e r s i t y of C a l i f o r n i a , L o s A n g e l e s , C A 9 0 0 2 4

MAGNETIC RESONANCE IMAGING OF THE VESTIBULAR AQUEDUCT: VISIBILITY OF THE VESTIBULAR AQUEDUCT IN MENIERE'S DISEASE M.Noda,T.Maehara,Y.Katsumata,l. Shirouzu Department of Radiology,Kanto Teishin Hospital

A Phase III, multi-center open label study was performed to evaluate the safety and efficacy of a non-ionic chelate of Gadolinium. 133 patients with presumed head a n d neck pathology were examined with magnetic resonance imaging prior to and following intravenous administration of 0.1 m m o l / k g Gadolinium 1,4,7 - iris ( c a r b o x y m e t h y l ) - 10 - ( 2 ' - h y d r o x y p r o p y l ) 1,4,7,10 tetraazacyclododecane, [Gadoteridol injection]. Eight patients (6%) experienced adverse effects, all of which were graded by the investigators as mild. Changes from baseline laboratory values occurred in seven patients (5.3%). No patients demonstrate a rise in serum iron or bilirubin such as has been described following administration of gadopentetate dimeglumine. Scans were evaluated by a n u n b l i n d e d reader at the site where they were performed. In 92 patients (69%), the post-contrast MR images provided more information than the pre-contrast study. Common benefits were improved visualization (69), better definition of lesion borders (66), lesion detection (39), disease classification (23), increased number of lesions (10), and determination of recurrent tumor (4). These results demonstrate that Gadoteridol is an efficacious contrast agent for MR imaging of head and neck pathology. In addition, Gadoteridol is safe in clinical use, with a low incidence of mild adverse effects.

Poster 7 PETROUS APEX MUCOCELE: HIGH RESOLUTION CT DIAGNOSIS MEMIS, H, ALPER, A. MEMIS Dept. o f Radiology, Hospital o f Ege U n i v e r s i t y Purpose: P r i m a r y lesions of the p e t r o u s a p e x are rare. Mucocele is a destructive tumor-llke process, originating in the air cells of the p e t r o u s apex. Difficulty of e x a m i n a t i o n of t h i s region b y direct a p p r o a c h obviates the u s e of indirect e x a m i n a t i o n m e t h o d s , a m o n g w h i c h h i g h r e s o l u t i o n c o m p u t e d t o m o g r a p h y {HR-CT} is h i g h l y praised. Case Report: A twelve-year-old girl p r e s e n t e d with left VI t h nerve palsy. Routine cerebral CT revealed a destructive lesion in the left p e t r o u s a p e x w i t h o u t a p p e a r e n t c o n t r a s t e n h a n c e m e n t , C o n v e n t i o n a l c r a n i o g r a m s , h i g h r e s o l u t i o n CT a n d selective carotid arteriography were performed, A circumscribed i n t r a - o s s e o s lytic lesion with s h a r p , lobulated c o n t o u r s w a s p r e s e n t in the left p e t r o u s apex. A t t e n u a t i o n values were m e a s u r e d between +4, +11 HU. A r t e r i o g r a m s disclosed a slight i m p r e s s i o n o n t h e p e t r o u s p a r t of lpsllateral internal carotid artery. Conclusion: The r a r e case reports in radiologic literature quotes t h e radiologic findings of p e t r o n s a p e x m n c o c e l e a s nonspesffie, while postulating several speculations on the pathogenesis. However, we believe t h a t , s h a r p , l o b u l a t e d c o n t o u r s of a n eroding, n o n e n h a n c i n g m a s s lesion within t h e p e t r o u s a p e x a s d e m o n s t r a t e d b y HR-CT. a l o n g w i t h a s y m m e t r i c , single, l a r g e a i r cell a t t h e opposite p e t r o u s a p e x c o m p r i s e c h a r a c t e r i s t i c d i a g n o s t i c criteria for p e t r o u s a p e x mueocele. Review of the literature revealed similar radiologie f i n d i n g s favoring o u r belief. The radtological f i n d i n g s supports the previously postulated "pneumotising air tract obliteration" h y p o t h e s i s on the p a t h o g e n e s i s of t h i s r a r e entity.

The purpose of this paper is to evaluate the diagnostic value of Mill in Meniere's disease. It is thought that the endolymphatic duct and sac play an important role in the etiology of Meniere's desease. High-resolutional CT can demonstrate only bony capsule,but MRI detect the lymph itself in the vestibular aqueduct(VA). Methods; MR imaging was perfomed using GE SIGNA ADVANTAGE 1.5T system with 3-inch surface coil. T2-weighted (TR 2500ms/TE 80ms) spin-echo images were obtained using a slice thickness of 3nm~, a field of view of 10cm and an acquisition matrix of 256X256. To bigin with,we determined the optimal scan plane for visualization of VA by MRI, then we examined MRI on I0 normal volunteers and i0 patients with Meniere's disease for comparison of the visibility of VA. Results; I) VA was most clearly demonstrated on sagittal plane. 2) VA was visualized only in 40% of the patients with Meniere's disease in contrast to 100% of normal cases. Conclusion;Poor visibility of VA on sagittal T2WI may indicate the possibility of Meniere's disease. We suggest that MRI is the valuable diagnostic method for detecting the abnormality of the endolymphatic duct and sac.

Poster 8 HIGH RESOLUTION CT IN TEMPORAL BONE PATHOLOGIES CAUSING CRANIAL NERVE INVOLVEMENT A. MEMIS, A, MEMIS, N. MADEN, H. OZER Dept. o f Radiology, Hospital o f Ege U n i v e r s i t y purpose: In t e m p o r a l b o n e pathologies, s e m p t o m s c a n be s e e n related to involvement of some cranial nerves b e c a u s e of the close a n a t o m i c relationship. Direct irritation of t h e G a s s e r g a n g l i o n in the Meckers cavity, a n d p a r t of the a b d u c e n s nerve along the course in the Dorello's c a n a l o n t h e petroclinoid ligament, i m p r e s s i o n of the fascial nerve in the t e m p o r a l b o n e a n d invasion of a lesion to the surrounding central nervous system tissues causes these s y m p t o m s . 18 c a s e s h a v i n g t e m p o r a l b o n e l e s i o n s w i t h v a r i o u s cranial nerve involvement are described in t h i s s t u d y . Methods: H i g h r e s o l u t i o n CT a p p e a r a n c e s of 18 p a t h o l o g i c t e m p o r a l b o n e were e x a m i n e d a n d t h e r e l a t i o n of t h e involved c r a n i a l nerves with the localization of t h e lesions were d i s c u s s e d . Results: V a r i o u s p a t h o l o g i e s t h a t c a u s e d c r a n i a l n e r v e involvement w a s recognized in 18 of 165 p a t i e n t s who were studied b y high resolution temporal CT, These pathologies are s u m m a r i z e d as follows: Infections(8)- Otitis m e d i a w i t h c h r o n i c c h o l e s t e a t u m ( 4 ) , c h o l e s t e a t u m of the petrous apex(l), a c u t e otitls media(3) Tumars(7)Glomus jugulare(2), glomus tympantcum(1), m e t a s t a s i s from b r e a s t c a n c e r ( l l , mucoeele of the p e t r o u s apex{ I), e x t e r n a l e a r , r a y s q u a m o u s cell c a r c i n o m a ( l ) , n e u r i n o m a of t h e fascial nervell) Fracture{2) A n e u r y s m ( 1) Conclusion: Routine cranial CT is i n a d e q u a t e in p a t i e n t s with s y m p t o m s of c r a n i a l nerve involvement d u e to lesions limited to the t e m p o r a l b o n e only. T h u s , h i g h r e s o l u t i o n CT is a v a l u a b l e s c r e e n i n g m e t h o d in displaying t h e p a t h o l o g y a n d e v a l u a t i n g the extend of the disease to s u r r o u n d i n g tissues.

S 196

Poster 9

Poster 10

CT STUDY OF THE LARYNGOCELES M. de Juan(l), P. Coscojuela(1), E. Guardia(1) J.Burgues(2), J. Ruscalleda(1). (i) Secc.Neuroradiologia (2)Serv. Otorrinolaring. Hospital S. Pau.Universidad Autonoma de Barcelona Purpose: To study the efficacy of CT in the diagnosls of laryngoceles and their relationship with underlying neoplasies when associated. Method: We reviewed retrospectively 35 patients with 43 laryngoceles (32 males and 3 females,aged 43-79 years, mean=59 years). Patients were examined with a 3rd.generation unit (Somaton DR2),with contiguous slices, 4 mm. thick, from the floor of the month to the trachea, and contrast enhancement. Results: Of our 43 laryngoceles 34 were internal, 4 external, 5 combined and 8 patients had bilateral laryngoceles. 17 patients presented concurrently a laryngocele (i bilateral) and a tumour. In 9 of those there was a direct relationship between both. In the remaining 9 there was no r e l a t i o n s h i p (5 were ipsilateral to the tumour and 4 contralateral) o In 2 cases we document with CT the desappearance of the laryngocele after the tumour decreased in size with chemotherapy. Conclusions:CT is the method of choice for studing laryngoeeles and associated tumour if present. In our experience in half of the cases t h e m is a direc~relationship between the laryngo~ele and underlying tumour.

PREMATURE CRANIOSYNOSTOSIS: Donauer E., Faubert C., Bernardi M., Neuenfeldt D. Premature craniosynostosis is the result of a premature closure of the cranial vault sutures, which originates for unknown reasons end which may cause a restriction of the interior of the skull, what is called cramiostenosis. Concerning the pathogenesis of craniosynostosis two contrary theories exist: on the one hand the premature closure of the skull sutures cause the deformities of the neuro- and viscerocranium w i ~ consecutive deformation of the skull-base: on t ~ other hand the deformity of the skull-base is regarded as the primary malformation, which is responsable for the development of a premature fusion of the sutures and other skull anomalies. However these theories also include various therapeutical operative consequences. We have examined 52 children with craniosynostosis before and after operative treatment (cIiniasl and radioiogical foIlow up between 2-12I (months). The examinations included beside a physical and neurological examination, especially measurements of head circumference, skull index and certain of the brain skuli, which permitted a detached judgement about the postoperative skull-dimensions. 800 measurements were statistically evaluated. With a standardized questionaire, we tried furthermore to have an impression of the postoperative physical, mental social development and the cosmetic result. An operative correction of the suture-anomaly by operative resection of the sutures and by crea~ ting artificial sutures in individually fitted surgical technique affects good functional and cosmetic satisfactory results with low intraoperative risk.

Poster 11

Poster 12

CLEFT LIP SEQUENCE

PAROTID

We present our experience in patients with cleft

TUMOURS

AUTHORS : K CHABOLLE.

: IMPACT

MARSOT

OF IMAGING

DUPUCH

.PH K A T Z

; M

FIRAT

, F

palate studied with conventional roentgenological studies, conventional competed tomography (CT) and three dimensional CT reconstructions. The cleft palate

is defined by failure in 'the

closure of both palatine processes in the All gradations of cleft lip and its

midline,

consequences

occur, from a scar line at the site of closure, to a widely open cleft with secondary consequences, such as flared ale nasi and ocular hypertelorism. In most cases, post-surgical tridimensional CT studies were also

perfomad.

AUTHORS: M. de is Fuente; J. Campollo; A. Ramos; d. Ferrendo.

Hospital 12 de Octubre

Object :The p u r p o s e of this exhibit is to describe and illustrate the imaging findings of parotid gland turnouts. Materials a n d m e t h o d s : 45 p a t i e n t s e x p l o r e d e i t h e r b y US , TDM or MR. R e s u l t s :MR appeared t h e b e s t w a y for t u m o u r c a r t o g r a p h y , e t i o l o g i c a l diagnosis, I l l u s t r a t e d exemples include s e v e r a l t y p e of a d e n o m a s p l e o m o r p h a s . a d e n o l y m p h o m a s , a d e n o i d cystic c a r c i n o m a s , h e m a n g i o m a s , l y m p h o m a s , i n t r a g l a n d u l a r m e t a s t a s i s , and m a l i g n a n t t u m o u r s . Some r a r e parotid t u r n o u t s a r e s h o w e d like t e r a t o m a s . Pittfalls in diagnosis are discussed including r a r e lesions as p a r o t i d p s e u d o c y s t in AIDS , h y d a t i c c y s t , a n d p s e u d o i n f l a m m a t o r y or p a r t i c u l a r content a d e n o m a s . Conclusions: MR a p p e a r s the best exam to distinguish intrinsic f r o m extrinsic l e s i o n s , especially for large deep parotid lesions and to e v a l u a t e turnout contents. It is probably) the first procedure to do w h e n a turnout r e d u x is s u s p e c t e d .

S 197

Poster 14

Poster 13 S~BASEIk~/ASIOI~

IN NASOPI~RY~'EALCARCINOI~:

CT EVALUATION C. C.LUI,T. J.I~IANG,R. J.LEE,T .Y.LEE,C. C. TSAI,~W.M.LEUNG, ~F.J.LIN DEPT. OF DIAGNOSTIC RADIOLOGY AND %RADIATI(~ (~]OL(~°Y, CHANG GU~G MEMORIAL HOSPITAL,CHANG GUNG MEDICAL C O ~ , TAIWAN,ROC PUPA~SE: In order to understand the patterns and routes of skull base extension in T4 cases of nasophary~eal carcinoma. N~HODS: Pre-treatment CT of 45 histopathologically verified cases were reviewed. All had axial views with IV contrast enhancement(Sm slice thickness for nasopharynx and skull hase;7mm thickness for the neck portion up to C7 level),and coronal views had been attempted in all of the cases. RESULTS: (I) Incidence and location of skull base invasion:petrous pyramid(posterolateral):80%;great wing of sphenoid bone(superolateral):42%;sphenoid sinus(superior) :69%;clivus(posterior):58%;sup. orbital fissure(anterosuperior):18%;posterior cranial fossa:4%. (II) Twenty-four cases(24/45:52%) had intracranial invasion,in which 96%(23 cases) invaded the middle cranial fossa. CX~OLUSI~: (I) Pharyngobasilar fascia is a barrier to limit the extension of skull base invasion;(2) Petrous pyramid is the most c o ~ o n site of skull base invasion; (3) Coronal cut is very important in the evaluation of T staging.

Poster 15 MRI OF HARD PALATE MALIGNANT NEOPLASMS. AUTHORS: L. Lopez Ibor; J.Sada; M.de la Fuente;H.Moreno; Cl~nica La Paloma We present three cases of malignant neoplasms affecting the region of the hard palate diagnosed by MRI, the pathological diagnosis was one Carcinoma, one Lymphoma and one Leyomiosarcoma. Allthough these neoplasm have a different histological origen they shared in common the lack of syntomatology and the agressive appearence at the time of presentation with great osseus destruction and invasion of adyacent structures. MRI is of great utility in order to asses the extension of the tumor and in planning the surgical aproach.

MRI OF SALIVARY GLAND LESIONS

AUTHORS: L, Lopez Ibor; d. Sada; H. Moreno; M.de l a Fuente A.Rames. Clinica de La Paloma We present 15 cases of neoplasm affectin major and minor salivary glands studied with MRI. MRI is veru accurate in defining the anatomic bdundaries affected by tumor and can sometimes differentiate benign from malignaut lesions. We conclude that MRI is a very useful technique in the study of the salivary glands as it can help in planning the surgical apreach which can be transfacial or transoral depending on the structures affected.

S 198

Posters ESNR Poster 16

Poster 17

SINGLE SESSION NECROTIZING RADIATION DOSE DELIVERED BY GAMMA KNIFE: MRI AND CT MANIFESTATIONS OF BRAIN PARENCHYMAAFTER TREA~NT WY Guo, T Hindmarsh, M Lindqvist, K Ericson, C Lindquist, L KihlstrSm, P Mindus Departments of Neuroradiology, Neur0surgery, Psychiatry and Psychology, Karolinska Hospital and Karolinska Institute, Stockholm, Sweden. Department of Radiology, Veterans General Hospital, Taipei, Taiwan, R.O.C.

CEREBRAL MANIFESTATION OF ERDHEIM-CHESTER DISEASE WITH PROLONGED TAKE-UP OF GD-DTPA

Purpose: Using the MR Imaging and CT scan to evaluate the in vivo manifestations of the brain parenehymal changes after single session necrotizing dose radiation. Method: Nine patients with a clinical diagnosis of obsessive-compulsive disorder and intractable to all medical treatments were referred for capsulotomy using the Gamma Knife. With the guidance of stereotaxic MRI and CT scanning, a m~:imum radiation dose of 200 Gy to the target and a minimum of 160 Gy marginal dose was given to the bilateral anterior limbs of internal capsule in these nine cases. Follow up examinations with MRI and CT were performed at regular intervals between three and 24 months after treatment. The volume of radiation induced damage (RID) was measured and analyzed. Result and Conclusion: The MRI and CT manifestations of RID reflect a dynamic change. The damage reaches its maximal volume between six and nine months after radiation. In I0 of 18 lesions RID resolved and stabilized at one year after treatment. In the other lesions the damage had not yet stabilized. The radiation dose, the time-RID relationship and their imaging pattern can be used as a reference for other indications of radiosurgery with the Gamma Knife.

E r d h e i m - C h e s t e r disease (ECD) is s r a r e d i s o r d e r of

mesenehymal tissues characterized by lipid grenulomo in the long tabular bones and typical roentgenological features. A symmetrical sclerosis of the spongiosa of the metaphyses and diaphyses of the long tubular bones sparing the epiphyseal regions is pathognomonlc. Because S-100 positive foam cells were found, ECD is believed to belong to the entity of histlocytosis X. ECD manifests intraoranially in two ways: (1) infiltration of tissues of mesenchymal origin like the meninges and (2) white matter lesions predominantly located in cerebellum, ports and medulla oblongata. We observed a 62 year old male patient with ECD which manifested in lungs, pleura, long and short tubular bones, pons, cerebellum and plexus chorloldeus. The lesion in the plexus showed a prolonged uptake of Gd-DTPA over a period of at least 14 days.

Poster 19

Poster 18 GADOLINIUM - DTPA ~ ENCHANCED IMAGING IN DIABETES INSIPIDUS

C . K u j a t (2), M . H e r m e s (3), T.Scherb (2), H . H a d i d i (2), B.Junk (2), P.Benz (4), A . K r e t s c h m e r (3), J . M a r t i n (5), W.Dewes (l) F u n k t i o n s b e r e i c h K e r n s p i n t o m o g r a p h i e (1) des Instituts for N e u r o r a d l o l o g i e (2), der A b t e i l u n g fur R a d l o d i a g n o s t i k (3) und N u k l e a r m e d l z l n (4) der Radiologisehen Klinik, N e r v e n k l i n i k / Neurologle (5) der Universlteit des S a a r l a n d e s , D-6650 H o m b u r g Sear

MAGNETIC

RESONANCE

A . C . A t h a n a s s o p o u l o u I, A.D. Gouliamos l, A. Souvatzoglou 2, A, K a l o v i d o u r i s : , G r Kotoulas I, L. VIahos I, C. Papavassfliou:. Dept. of Radiology I A r e t e i o n H o s p i t a l Univer. of A t h e n s Med. School a n d E n d o c r i n o l o g y2, A1exandra Hospital, Athens, Greece. The p u r p o s e of this s t u d y is to evaluate the u s e of Gd-DTPAe n c h a n c e d MRI in the detection of pituitary diabetes i n s i p i d u s {DI) in c o m p a r i s o n with the findings of (71". 11 p a t i e n t s (5 children a n d 6 adults) with clinical d i a g n o s i s a n d l a b o r a t o r y f i n d i n g s consistent with DI were examined by MRI using a s u p e r c o n d u c t i n g G E - C G R m a g n e t o p e r a t i n g at 0.5 Tesla. MR e x a m i n a t i o n w a s performed between 2 m o n t h s a n d 2 5 y e a r s following the onset of s y m p t o m s , P o s t - t r a u m a t i c a n d p o s t - s u r g i c a l p a t i e n t s with DI were excluded from this s t u d y d u e to self-evident etiology. Absence of the posterior lobe bright signal w a s a p p a r e n t in all p a t i e n t s examined b y plain MR imaging, In 5 p a t i e n t s a s u p r a sellar m a s s w a s identified in the h y p o t h a l a m i c region. T h e s e m a s s e s were not d e m o n s t r a t e d b y CT. There w a s inhomogenious e n h a n c e m e n t in 2 c a s e s a n d r i n g e n h a n c e m e n t i n 2 c a s e s i n f u n d i b u l u m thickening w a s observed in 3 cases. Coincidence of m o r e t h a n one pathologic sites w a s evident in 3 c a s e s . In the remaining 6 patients pituitary-hypothalamic region appeared n o r m a l a n d DI w a s considered idiopatic, C o m p a r e d to CT, MR is a more sensitive m e t h o d for detection of p a t h o l o g y of t h e p o s t e r i o r p i t u i t a r y lobe a n d h y p o t h a l a m i c region. G D - D T P A - e n h a n c e d MRI c o n t r i b u t e d in t h e d i a g n o s t i c a c c u r a n c y of the s t u d y a n d especially in s e c o n d a r y DI for better diagnosis a n d patient m a n a g e m e n t .

SPONTANEOUS DISSECTION OF EXTRACRANIAL VERTEBRAL WIT~ SPINAL SAH IN A PATI~IWT WITH B ~ K ~ T ' S DISEASE S.Bahar, O . ~ 9 a n , H.G[lrvit, G.Akmmn, A . G ~ i ~ i t D e ~ t of Neurology, Ishanbul Medical Faculty, I stanbul TURKEY Brainstem ischemia is the common presentation of spontaneous vertebral artery dissections (VAD). Although less common, subarachnoid hemorrhage may well occur. Behqet's disease (BD) is known to involve vessels of all types and sizes. Arterial m ~ e s t a k i o n s are occlusions, aneurysms and pseudoaneurysms. A 40 year old man with known definite BD ~ admitted with oonfusional state which had started 4 days before admission with an acute headache and vomiting. Neurological examination revealed confusion, stiff neck, right facial weakness, left hemiparesis, dysartria and trunc~l ataxia. CSF was hemorrhagic and xanthochromic. Cranial CT scans were negative, but MRI showed a right pontine hyperintense lesion on T 2 weighted immges. Bilateral carotid angiograms were nolmml. Right vertebral angiogram showed findings oonsisherfe with a dissection at V 9 segment of the artery. At C~ level a radiculomeduIlary branch of VA with an an~al~smal dilatation in its intradural portion was notable. To our knowledge, there is no other reported case presenting with S~H secondary to extracranial VAD. We conclude that BD must be added to the list of conditions associated with spontaneous VAD.

S 199

Poster 20

Poster 21

MR-STUDY OF LEUKODYSTROPHIES

MR APPEARANCE OF SUBDURAL AND EPIDURAL E~PYENAS WITH EMPHASIS ON FINDINGSOF ENHANCEDIMAGES

C. Faubert (l),Ph. Demoerel (2), J.L. Dietemann (3), G. Wilms (2)

K.Tsuehlya and K.Makita Department of Radiology, National Defense Medical College, Saitama, Japan

Deportments of Neuroradiotogy (i) Saarland-University, Homburg-Soar, FRG, Radiology (2), Leuven University Hospitals, Belgium, Radiology (3), University Hospital, Strasbourg, France The authors report the additional information obtained by MRI as compared to CT. 14 patients were examined with 0,5 T, 1,0 T and 1,5 T MR-imagers. There were 8 adrenoleucodystrophles, 3 metachromatic leucodystrophies, and 3 globoid cell leucodystrophies. MRI is more sensitive and provides a superior neuroanatomical demarcation of the lesions involved. More specifically the sub-cortical white matter lesions, the brain stem and the cerebetlor lesions are better visualized. MRI allows an earlier diagnosis. Nevertheless the diagnosis has to b~ confirmed biochemically and histologically.

Poster 22 MR FINDINGS IN TUBERCULOUS MENINGOENCEPHAL1TIS Ph. Demaerel, G. Wilms, C. Faubert**, W. Robberecht,* H. Carton*, U. Piepgras**, A.L.Baert, Depts. Radiology and Neurology*, University Hospitals K.U. L e u v e n , B e l g i u m and Institut fiir Neuroradiologie**, Universi~tsktiniken Homburg-Saar The purpose was to compare CT and MRI as diagnostic tool in tuberculous meningoencephalitis (TBM). Five patients (3 if, 2 Q) were examined by CT and MRI (Magnetom 1.5 T). T1 weighted images before and after Gadolinium (Gd)-DTPA enhancement were obtained in all patients and T2 weighted images in four patients. Abnormalities were seen in all patients, but MRI was superior in lesion detection and delineation. CT was interpreted as being normal in 3/5 patiens. T1 weighted images after Gd-DTPA enhancement were superior to T2 weighted images. Especially brain stem and cerebellar lesions were better visualized. Meningeal hyperemia and focal tuberculomas could easily be depicted. MRI should become the radiological examination of choice in TBM. Gd-DTPA should be administrated routinely.

Purpose: This study describes the MR appearance of extraaxial empyemas placing emphasis on enhanced-MR findings. Materials & Methods: We reviewed MR findings in five patients with subdural empyeaa (SDE) and two patients with epidnral empyema (EDE). In addition to TI- and T2-weighted spin-echo images(TIWIs and T2Wls, respectively), gadopentetatedimeglumine -enhanced TIW[s were obtained except two patients with SDE. Results: Enhanced images apparently showed enhancement of the

capsule in both lesions. Additionally, in SDEs, they clearly demonstrated thickening of the neibouring dura (three patients) and coexistent brain abscess (three patients). In EDEs, part of the adjacent dora remained unenhanced showing low intensity. This facilitated discrimination between SDEs and EDEs. in both lesions, the content, which did not show enhancement, demonstrated high intensity on T2WIs and low intensity higher than that of cerebrospinal fluid on TtWls. These intensities enabled differentiation of these lesions from other extraaxial lesions. Conclusion: Enhanced MR images readily show the capsules and coexistent abnormalities whose findings are important in establishing the therapeutic procedure. Thus, MR inaging, especially enhanced study, is of great value in the diagnosis of these lesions.

Poster 23 CT AND MRI OF LHERMITTE-DUCLOS DISEASE F. J. R o m e r o , A . O r t e g a * ,B . I b a r r a , A . Vivas, P.Fernandez,C.Sanchez S e r v i c e s of N e u r o r a d i o l o g y a n d N e u r o p a t h o l o g y * Ha spltal Univer sit aria d el "Valle Hebrrn:Barcelona(Spain) Since 1920 when Lhermitte-Duclos first described a tumorlike abnormality of the c e r e b e l l u m , t h e r e h a s b e e n an i n c r e a s i n g n u m b e r o f r e p o r t s o f t h i s r a r e e n t i t y . O n l y few c a s e s w e r e reported with CT a n d two c a s e s w i t h MRI. We report three cases of Lhermitte-Duclos d i s e a s e w i t h C T a n d one w i t h M R I . A I I of t h e m w e r e woman. The C T f i n d i n g s w e r e : l ) h y p o d e n s e n o n h a n c i n g mass in the p o s t e r i o r lasso 2)supratentorial h y d r o c e p h a l u s w a s p r e s e n t in all c a s e s . M R I s h o w e d a l o w s i g n a l o n s h o r t T R / s h o r t T E and p r o m i n e n t c e r e b e l l a r f o l i a in one h e m i s p h e r e a n d v e r m i s . O n long T R / l o n g T E t h e r e was a b n o r m a l increased s i g n a l in the c e r e b e l l a r h e m i s p h e r e . The biopsy after surgical removed proved L h e r m i t t e - D u c l o s d i s e a s e in the t h r e e cases. We think the combination of h y p o d e n s e non enhancing lesion in t h e p o s t e r i o r fossa and u n i l a t e r a l h e m i s p h e r e e x p a n s i o n i n C T in a w o m a n of m i d d l e - a g e a d u l t s h o u l d r a i s e the p o s s i b i l i t y of L h e r m i t t e - D u c l o s d i s e a s e . T h e MRI f i n d i n g s m a y be m o r e s p e c i f i c .

$200

Poster 24

Poster 25

CRANIAL MRI IN PATIENTS WITH SJ~GREN'S SYNDROME D. Escudero, P. Latorre, M. Codina, A. Olive, J. Coll Services of Neurology and Rheumatology, Hospital General "Germans Trias i Pujol", Badalona, Barcelona. Service of Internal Medicine, Hospital del Mar, Barcelona.SPAIN.

WRFINDINGSOF PITUITARYADENOWASWITH INTRATUNORALHEMORRHAGE K.Tsuchiys, LWakita, and S.Furui Department of Radiology, National Defense Nedloal College, Sultana, Japan

Primary Sj~gren's Syndrome (PSS) is an autoimmune disease with multisystemic manifestations. Cnetral nervous system (CNS) involvement is not accepted by all. We present i0 patients with PSS and clinical and radiological evidence of CNS impairment. All patients fulfilled Fox's criteria for diagnosis of PSS and were evaluated at least once by the same neurologist and rheumatologist. In addition, ESR, antinuclear antibodies, anti-DNA, anti-Ro, anti-La and anti-phospholipid antibodies, rheumatoid fac tor and cerebrospinal fluid analysis, were determined. MRI was done using a 1.5 Tesla superconducting magnet,with i0 to 15 multislice 5 to i0 mm, in axial, sagittal and co ronal planes. Tl-weighted, T2-weighted and spin density images were obtained, using a two dimensional Fourier transformation, with a matrix of either 256x256 or 256x192 with a 24-cm field of view. The analysis was blind as to the clinical status of the patient. Our findings consisted of bright small lesions in the cen trum semiovale and periventricular white matter. Larger areas, including confluent lesions in the parieto-oceipital and frontal subcortical white matter~ were also obser ved. These larger lesions were also present in a neurologically asymptomatic patient. To summarize: We report the MRI characteristics of CNS ab normalities in a group of patients with PSS. While some patients showed evidence of small hyperintense lesions on T2-weighted images,other lesions were larger and confluent. Both types of lesions were present in both asymptomatic cases and in patients who presented only with psychiatric troubles.

Purpose: Intratuworal heacrrhage(ITH) is known to be frequent within pituitary adenomas. Oar purpose was to determine the spectrum of its MR findings. Netbeds: We retrospectively evaluated ~ (1.ST) and CT findings of ten patients with surgically proved pituitary ITH. Results: Clinically, pituitary apoplexy was experienced only in two cases. CT disclosed high density suggesting hemorrhage in five cases. ~R findings were classified into throe groups. ITH of three cases(group I) showed hyperintensity on TI- and/ or T2-weighted images. In five cases(group H), a fluid-fluid level was delineated within ITH. The upper part showed hyperintensity, while the lower part demonstrated isointensity or hypointensity on both sequences. In the remaining two oases (groop In), ITH showed a wixture of abnormal intensity. Conclusion: The hypvrintensity in groups I and H probably reflects the accumulation of free methenoglobin ; this was verified in two eases in group H through hemoglobin analysis of surgically obtained hematona. Hemorrhage within necrotic component is assuwed to be the causative mechanism of the fluid -fluid level in group H. In group Ill, hemorrhage of various stages may be reflected. Thus, although the MR appearance of the pituitary ITH is somewhat complicated, MR imaging depicts it sensitively and provides detailed inforsation on its contents.

Poster 26

Poster 27

MR IMAGING IN PRIMARY CEREBRAL NEUROBLASTOMA

CT AND MR IMAGING OF DEMenTIA J.Walecki, w.chmielewski, A.Szczudlik, J.Brzezi~ski Neurosurgery Clinic PASci, Section of Medical Sciences, Polish Academy of Sciences Warsaw, Poland

P. JAMBLIN ( I ) , d. COLLIGNON (1),P. FLANDROY ( I ) , J. LENELLE (2), J.P. MISSON (3), M REZNIK (4) (I) Department of Radiology, (2) Deparment of Neurosurgery, (3) Department of Paediatrics, (4) Department of Neuropathology. CHU Sart Tilman, 4000 Liege, Belgium. Primary CNS neuroblastoma is a rare supratentorial tumor of child which is not well defined c l i n i c a l l y and p a t h o l o g i c a l l y and r e l a t i v e l y unknown in MR imaging. We present two patients with s u r g i c a l l y and h i s t o l o g i c a l l y proved primary cerebral neuroblastoma. Both had CT and MR examinations. The f i r s t one is an asymptomatic 10-year-old boy presenting a 6 cm intraparenchymal tumor located in the right frontal lobe, close to the f a l x cerebri. The second one is a 34-year-old girl admitted for an inaugural seizure and showing a 4 cm right orbitofrontal mass lying on the orbital roof. On CT examinations, tumors were mildly hyperdense with hypodense areas and showed heterogeneous contrast enhancement. MR examinations revealed an intraparenchymal mass with areas of low and high signal intensity on T1-weighted images. No surrounding edema was found on T2-weighted studies. T1-weighted gadolinium studies resulted in intense heterogeneous enhancement of tumor in the f i r s t case and a moderate peripheral enhancement in the second case. Both lesions were well circumscribed and their intracerebral location and hemorrhagic loci were better specified with MR than with CT. CT and MR appearances of cerebral neuroblastoma are not specific and histological verification is required for definitive diagnosis.

CT and MRI scans have been performed in 76 patients with dementia. The images demonstrated a variety of morfological patterns, asessment of son~ of them being one of the objects of this study. The patients have been grouped in three categories: possible/probable Alzheimer's disease (AD), multi-infarct dea~ntia (MID), and mixed AD/MID, on the basis of clinically detelmlined Haci~ski ischemic score. Strong correlation has been established between the ischemic score and the severity of paraventricular and subcortical lesions found in MRI scans. The ability to distinguish between different types of dementia on the basis of CT scans was relatively low. Periventricular lesions were observed in ~ scans in almost all the patients with AD and MID although some differences have been noticed. Other lesions associated with AD and MID have been described and conpared with the clinical stage. As we observed, neuroradiological evaluation of dementia is an essential element of the final diagnosis of this severe disorder.

S 201

Poster 28

Poster 29

MR TOMOGRAPHY OF AGYRIA B.Junk (1), A.Kretschmar (2), P. Benz (2), W.Dewes (2), G.Huber (1)

NEURORADIOLOGICAL FINDINGS IN HIV~RELATED COMPLICATIONS OF THE CNS AND CONSIDERATIONS ABOUT MRI VERSUS CT U.Dietrich, R.MaleBa, K.W.Sievers, N.Brockmeyer R6ntgendiagnostisches Zentralinstitut, Universit~tsklinik Essen, Germany

Department of Neuroradiology (I) and Magnetic Resonance Section (2), Saarland-University, Homburg-Saar, FRG Agyria (lissencephaly) is a rare congenital anomaly caused by arrest of neurobtast migration between 8th and 16th week of gestation. In most cases agyria is associated with areas of puchygyrla. We report a case of a 5 month old girl admitted at hospital with severe seizures and psychomotoric retardation, somatic malformutions were not found. The characteristic MR findings are: absence of gyrl wlth smooth thickened cortex, reverse of the ratio gray/whlte matter, microcephalia, mild hypoplasia of brainstem and cerebellum. The MR images are interpreted in correlation with neuropathologicol and embryological data published in the literature.

96 patients with clinically suspected HIV-related complications of the CNS underwent CT (59 pat.) or MRI (ii pat.) or both (26 pat.). Normal findings were obtained in 23 patients and 23 pat. showed signs of atrophy. Single mass lesions were due to toxoplasmosis in 8 of 12 patients, to lymphoma (I/12), astrocytoma (I/12), and of unknown origin (2/12). Multiple mass lesions responded to toxoplasmosis t h e r ~ i e in almost all cases (11/13) with the exception of two (2/13). Non-space Occupying white matter lesions were related to viral infection (7/13), to toxoplasmosis (I/13), and remained without clinical diagnosis in 5 cases (5/13). Meningeal enhancement was an additional finding in 4 patients. Miscellaneous findings were subdural hematoma, intracerebral hemato~a, infarction, parenchymal defect, connatal abnormalities, sinusitis and Kaposi sarcoma of the skin. Comparison of the findings in 26 patients with CT and MRI revealed non-significant additional findings in 4 patients and significant additional findings in 9 patients. These additional findings and the superiority of topographic localizationand without the need of a double dose delay-technique make MRI studies superior to CT in evaluation of CNS diseases in HIV-infected patients. Therefore we recommend MRI as a primary investigation in patients with suspected cerebral complications of the HIV-infection.

Poster 30

Poster 31

CT OR MRI FOR THE WORK UP OF INTRACRANIAL MANIFESTATIONS OF AIDS? H. H e n k e s *°, R. J o c h e n s °, G. H u b e r * , W. S c h 6 r n e r °, J. A r t i g a s +, , U. P i e p g r a s * Institut f~r Neuroradiologie, Nomburg/Saar*; Institut f~r Pathologie, ArK Berlin+; Radiologische Klinik, U~RV/SC, Freie Universit~t Berlin

PSEUDOTUMOR SIGN IN GD-DTPA ENHANCED MRI OF CEREBRAL INFARCTION F. Kioumehr, M.R. Dadsetan, S.A. Rooholamini, A. Au, I. Yaghmai University of California at Los Angeles-Olive View Medical, Sylmar, California, U.S.A.

~ Of the preser~sd study was to ~ the diapncstic scope Of CT and MRI in the detection and classificatios of intracranial manifestatiQ1s of A I ~ . Patients a~d methods: In a i:~ospective study, 185 patients (18 female, 167 male, a M range 20-63 years, median 36 years) with SuS~M~ted Or intracranial manifestations of AIES u ~ e r a ~ Z correlated CT and FRI ex~minatiGns. All incllx]ed exarimaticns were ~ c¢i 3zd generation CT scanners and c~ a 0.5 T Magnetcm within a time interval of 9 days (metal). The spectrau of o~nfizm~l diagnoses was in acccrdano~ with those Of other centers. It included t ~ a m m a s i s (64 ~ts), P~L (14 pts), PEL (5pts), CNS l~m(3 pts) and other, rare etiologies. Results: to £T ~s MP~I: (~ and MRI yielded equa/ diagr~stic in~zmati~xl in 120/185 patients, including 49 rlorasl f ~ , 32 cases with brain atrophy and 32 cases with ~ d % s a ~ l lesicr~, either alc~e or o~ubined with atrq0hy. CT was s~g~r/or to ~ in 1/185 patients with multiple, partially c~icified lesions. C'£ ~ s infer/or to M~I in 64/185 cases. In 36 ¢f these, a p a r e ~ manifestation was detected by C~ whereas MRI z~=vealed rare lesions or mmlifestatior~ in different locations. A total Of 28 MRI e x a ~ r~tior~ ~ r a t i n ~ intracraxial patho]ngy went along with definitely normal CT scans. ZIo T2-WI vs Gd-Di!~ e~h. TI-WI: ~-~1%~re ~ to Gd-lYI~A e~h. TI-NI in 49/93 cases, including 13 nol~l~l findir~s, brain atrophy in 13 and p a r ~ o c ~ l or m ~ lesions in 30 cases. ~ e assessmm~ Of the underlying etiolcsy and Of the a c t ~ n ~ of lesions was ju~ded to be equal on the basis Of T2-WI ~Id Of Gd-Er/PA e~h. TI-WI in 35/93 CaSeS. In 58/93 cases both aspects coudd significar~ly be ccz~sidered ~_n a ra3re aplXOI~iate ~ y ~ ~ - D I ~ A er~L T I - ~ were included in the wc~k t%0. In conclusion, C~ r ~ a i n s the pr/rcary insging m3dality in A/DS patients with ~ e d i n ~ l manifestations of the disease. In cases without c~ncozOax~e of clinic81 syaptoms and CT find/ngs, I~ im~giro, obligatory includir~ Gd-DYPA ~ sc~r~, can offer sipnificar~ a d d i t i ~ l dia9~stic infomstlca.

Purpose: To present the patterns of MR contrast enhancement in acute and subacute cerebral infarction and to describe pseudotumor sign. The contrast enhanced MR images of 30 patients with acute and sub acute cerebral infarction brain infarct were reviewed. Ten of them were studied within the first three days. Various patterns of abnormai enhancement were observed in 27 patients. In 8 cases, diffuse enhancement resembling a tumor occurred (pseudotumor). The diffuse pattern of enhancement was observed in the posterior drculation territory. In conclusion, diffuse patterns of Gd-DTPA enhancement can occur in cerebral and cerebellar infarct and knowledge of this finding may aid in differential diagnosis from tumor and infarct.

S 202

Poster 32 ~!

IN E~-hEE~Sm4- M ~ I A

Poster 33 - ~4@N_"SIS C~= 11 ~EIES.

V.C. She.h.S.B. Basal, *P. Phadke, *8. Shah, ~M. Doctor~ O.J. Tavri, P. Rao, A. K~hli Breach Car~y Kiz~pital ~ Re=~_arch Centre, B ~ y ~ I~dia 8Jjarat Cer~er & F.'~-~earch Institute. Ah~edabad,

Eleven F~ti~-~ts w i t h studied with ~I.

India

~_~_=.~=+~qd c e r e b r a l m a l a r i a ~ r e All. ~ t i ~ - ~ t s ~ r e s t u d i e d c~

Siesens Mz~netc~ ~percc~ductir~ Magnets operating at I.OTESLA and 0.5TECq~A. Both T1 ~ d T2 weighted spine~ho imagee- ~-~_-reobtained. In 9 patient=_., Ti weighted images revealed petechia! discrete ~ r a ventricular ard rarely cortical hyger inten=Je fcci which r-e~ined b/per inteT_~e on T2 ~ i g h t e d i~ge-~, cor~_istent with vetechial t~e~rrb~ges. In ~ne patier~t, a fcca! diffuse ~/per intensity in tke cerebral ~ i s p h e r e , consistA3t with cerebritis, which di=_appeared totally, was seen. In one pati~Tt~ similar ck~rrL~- ~ r e =_eer, in t~he cerebellL~m. T£e di~appear~7ce of the lesi~.s was fc~r~ cc~sistent with clinical improvement. Tke ro!e and die~no~ti~ efficacy of MRI in cerebral malaria is discussed°

NONSPECIFIC MENINGEAL ENHANCEMENT OF GADOLINIUMDTPA D.Papadoulis (4), B.Junk (2), P.Benz (4), A.Kretschmer (3), W.Dewes (1) Funktlonsbereich Kernspintomographie (1) des Instituts for Neurorodiologie (2), der Abteilung for Radiodiagnostik (3) und Nuklearmedlzin (4) der Radlologischen Klinik der Unlversltat des Saarlandes, D-6650 Homburg-Scar 11 patients with a strong meningeal enhancement o f Gadolinium-DTPA visualized by MR tomography are reported. This intensive perfuslon was not or only alluslvely seen in CT scans performed at the same time. These changes were caused by inflammation, radiation therapy or chemotherapy and are interpreted as nonspeciflc meningeal reactions. The evaluation of those nonspeclfic reactions is important especially to differentiate them from malignant meningeal infiltrations in patients with malignant diseases.

Poster 34

Poster 35

CT AND MR TOMOGRAPHY OF TUBEROUS SCLEROSIS H.Hadidi (2), A.Kretschmer (3), P.Benz (4), G.Huber (2), G.Brill (1), W.Dewes (1) Funktionsberelch Kernsplntomographie (1) des lnstituts fur Neuroradiologie (2), der Abteilung fur Radlodiagnostik (3) und Nuklearmedizin (4) der Radiologisehen Klinik der UniversitOt des Saarlandes, D-6650 Homburg-Saar

MIDDLE FOSSA ARACHNOID CYST WITH SUBDURAL HEMATOMA AND SEQUELAE OF TEMPORAL LOBE HERNIATION: CT AND MR STUDIES. J.M. Pumar, PI. Alvarez, P. Martinez, P. Rivas, A. Pardo Hospital General de Galicia~ S a n t i a g o de Compostela. Espafia.

Tuberous sclerosis is a more common disease (prevalence: 1: 10000) than normally suggested. 11 patients (10 children, 1 22-years-old woman) with tuberous sclerosis are reported. All children were epileptic, only 8 children had skin [eesions (white spots, adenome sebaceum), 4 children had rhabdomyoma of the heath 4 children had astracytoma o f the retina and only in 4 children the entire triad o f tuberous sclerosis was seen. The young woman with a hemorrhagic angiolipama of the kidney had no other symptoms of tuberous sclerosis. All patients were examined by CT and MRT, and both CT and MRT were pathologic in all patients. 4 different types of leasions were seen in MRT. For human genetics reasons, and to discover the underlying disease all children with epileptic disorders and also patients with partially expressed symptoms of the triad should be examined by MRT.

It h a s been i n c r e a s i n g l y r e c o g n i z e d t h a t p a t i e n t s with a r a c h n o i d c y s t o f t h e middle f o s s a a p p e a r m o r e s u s c e p t i b l e to t h e d e v e l o p m e n t of s u b d u r a l hematomas. One p a t i e n t with a h i s t o r y of p r e v i o u s h e a d i n j u r y p r e s e n t e d with a n i s o d e n s e s u b d u r a l hematoma with e x t e n s i o n into a p r e e x i s t i n g middle f o s s a a r a c h n o i d cyst. Plain s k u l l r a d i o g r a p h s s h o w e d t h i n n i n g o f t h e a n t e r i o r wall of t h e s p h e n o i i d . CT d e m o s t r a t e d a l a r g e mass

effect,

and

MR

evaluation

confirmed

a

large

s u b d u r a l hematoma with a r i g h t middle f o s s a a r a c h n o i d c y s t . At craniotomy a l a r g e chronic s u b d u r a l hematoma e x t e n d i n g from t h e f r o n t a l to t h e occipital pole overlaying the arachnoid c y s t was found. After evacuating the hematoma, CT and MR examination demostrated infartion in the distribution of the posterior cerebral artery, p r o d u c e d b y temporal lobe herniation

$203

Poster 36

Poster 37

SPONTANEOUS TENSION PNEUMOCEPHALUSSEVENTY YEAR8 AFTER HEADINJURY.CASEREPORT d.d.TeruelI,d.C.VilanovaI,E. BaYs2, I.LlodoI,M.D.FiguerasI , and D. Dal HoyoI Departmentsof IRadiologyand 2Neurosurgery. Hospitalde Oirona"Or.d~sep Irueta",Oirona,Spain A 76-Year-old femalewas admittedat our hospitalwith o historyof holocranealheadacheover a two-month period.8he had sufferedwlth a rhinorrhos, but this had been misdiagnosedas nasal mucosity.There was a remoteeventof severecraneafacialinjury seventyyears ago. On plain skull radiography, e large rounded intrecranial air collection communicating with the ventricular cavity was noted. Emergency CT showed a large intracrenial, subarschnoid and intraventricularpneumasephelus.Frontalpneumecephaluscontainedan air-fluidleveland was causingmass effect. Acoronal Ol performed with the head in hyperextension showeda

narrow passageof sir through to a bony defect right of the orlsta gelli. Due to the obvious diagnosis it was unnecosary to carry out the introduction of subarashnoid contrast.Surgical exploration confirmed the diagnosis and the patient was discharged on the 7th postoparstive day complstly essymptomatic. Tension p~mocaphalus rosyappear as a rare complicationin cases of traumatic, infectious,neoplasicor su~jicaldisease.We have not

CT IN CEREBRALASPERGILLOSIS A.Vivas,F.Romero,A.Ortega*,B.Ibarra,A.Rovira, R.Puy S e r v i c e s of N e u r o r a d i o l o g y and N e u r o p a t h o l o g y * H o s p i t a l G e n e r a l U n i v e r s i t a r i o del "Valle H e b r o n " B a r c e l o n a (Spain). Six cases of c e r e b r a l a s p e r g i l l o s i s w e r e s t u d i e d by CT.AII of t h e m w e r e i m m u n o s u p r e s s e d p a t i e n t s (three liver transplantation,one acute lymphoblastic leukaemia,one Behcet disease,one associated a high dose steroid).Neurological findings were non-specific. The p r i m a r y focus of i n f e c t i o n s was in the lung in four c a s e s a n d in the knee in the o t h e r one. The CT f i n d i n g s w e r e a b s c e s s e s w i t h a v a r i a b l e d e g r e e o f ring o r n o d u l a r e n h a n c e m e n t , l n f a r c t i o n s and h a e m o r r h a g e s . T h e spread into the s u b a r a c h n o i d space may result in meningitis and meningoencephalitis. Necropsy showed the correlation with r a d i o l o g l e a l f i n d i n g s in t h r e e c a s e s . T h e d i a g n o s i s was s t a b l i s e d b y b i o p s y in the o t h e r three. We t h i n k that c u l t u r e s are r a r e l y o b t a i n e d the t r e a t m e n t s h o u l d be s t a r t e d o n n e u r o r a d i o l o g y a n d c l i n i c a l s u s p i c i o n alone.

found any other report about spontaneoustension pneumocophalusafter having sustainedan injury over such e long period of time.

Poster 38 ATYPICAL ASPECTS

CAVERNOUS M.R.

Poster 39 ANGIOMAS.

NEURORADIOLOGICAL

N. FAYED; L. GUIMARAENS. C L I N I C A Q U I R O N ZARAGOZA. SPAIN. PURPOSE: The present study is b a s e d on the n e u r o r a d i o l o g i c a l e v a l u a t i o n of two cases studied with MR, one of w h i c h suggested m a l i g n a n t g l i o m a or m e t a s t a s e s , and the o t h e r g i a n t aneurysm. METHODS: In b o t h cases, the s y m p t o m a t o l o g y was acute, with moderate neurological sequelas which were the c o n s e q u e n c e of a h e m o r r a g i c episode. The s t u d i e s w e r e c a r r i e d out supraconductor G.E. O,5T. and the s e q u e n c e s S.E. TI a n d T2 w e r e used. RESULTS: One of the cases suggested malignant glioma or m e t a s t a s e s b e c a u s e of the g r e a t e d e m a and m a s s effect. The o t h e r case s u g g e s t e d a g i a n t a n e u r y s m w h i c h was partially thrombosed. In one case s u r g e r y and in the o t h e r angiography demonstrated the p r e s e n c e of c a v e r n o u s angiomas. CONCLUSION: Although MR shows up the t y p i c a l signs w h i c h c h a r a c t e r i z e the p r e s e n c e of m e t a h e m o g l o b i n , calcifications and m u r a l fibrosis or h e m o s i d e r i n deposited in the gliosis zones, there are c a v e r n o m a s which p r e s e n t a t y p i c a l signs in M R and w h i c h m a y lead to errors of d i a g n o s i s .

INTRAVENTRICULAR HEMORRHAGE E.Donauer (1), C.Faubert (2/3) Departments of Neurosurgery (1), Neuroradiology (2) and Diagnostic Radiology (3), Saarland-Universlty, Homburg-Saar, FRG At the hyperacute stage (4 6 HRS) CT should be performed. At a later stage MRI permits a more precise staging and localization. Of 200 consecutively treated patients we have selected those with subarachnoid hemorrhage 71 (which include 58 cases of a proven aneurysm) and 21 angiomas. Ventricular hematoma without intracerebral hematoma or subarachnoid bleeding is highly suspect of angiomo. In our experience it is important to apply a panangiography in all cases of intraventricular hemorrhage as soon as possible in order to detect cases of aneurysms or angiomatose malformations in which case the neurosurgeon can intervene. The retrospective study does indicate that the both angiomo and aneurysms with intraventrlcular hemorrhage, rebieeding is by far the highest single risk factor lifethreotening complications. The MRI evolution specific to IVH is discussed. The contribution of CT, DSA and MRI for the optimal management as a function of time is analysed.

$204

Poster 40

Poster 41

2D-FT LOW-FIELD MR ANGIOGP3tPHY OF INTRACRANIAL VASCULAR PATHOLOGIES. M.Gallucci, A.Bozzao, P.Pavone, P.Di Renzi, F.Caramia, A.Cifani, Z.Aprile, R.Passariello Dept. of Radiology, University of L'Aquila Italy

INTRACRANIAL MYCOTIC ANEURYSM IN CHILDREN: REPORT OF A CASE C.Faubert (1/2), E.Donauer (3) Departmentsof Neuroradiology (1), Diagnostic Radiology (2) and Neurosurgery (3), Saarland-University, Homburg-Saar, FRG

Two-dimensional Fourier transform (2D-FT) time-of-flight low field (0.2 T) MR angiography was performed in I0 healthy volunteers and in 30 patients with suspected intracranial vascular pathologies. In all patients conventional MRI had been previously performed. Our case material consisted of 8 patients who had previously undergone surgery (3 aneurisms and 5 AVMs) and 22 non-operated patients, out of these, 9 had artero-venous malformations (AVM), 7 aneurysms and 6 patients had sinus venous involvement by meningiomas. Five more cases of suspected sin~s involvement by meningicmas were also evaluated. In 31 cases comparative angiography was avaJ!able. All studies were performed with a standard head coil. A series of Z5 to 64 axial and/or sagittal images were obuair~ed. Low field MR angicgraphy was judged highly informative in evaluating dimensions and morphology of AVMs and in studying venous drainage. However, as previously described, MRA underesBimated the number of feeding vessels, six out of 7 aneurysms w e r e e q u a l l y depicted beth by angiography and MRA. The last one was not visualized by M RA because of its small dimensions. Four out of 6 sinuses involvements were evidenciated by MRA: the others, consisting in microinvasions, were clearly depicted only by conventional angiography. In our experience low-field MRA offers the same possibilities and has the same limitations of the high field one in evaluating intracranial pathologies.

Although aneurysms during childhood are unusual, mycotic aneurysms are responsible for 10% of the aneurysms encountered. A 6 year old gypsy girl was admitted with acute aphasia and right hemiparesis. Preoperative CT showed a hematoma of the left putamen. The preoperative conventional anglography showed an aneurysm of a distal branch of the medial cerebral artery. The aneurysm was clipped, and after serological and bacterial samples were taken ontlblotherapy was administered. Postoperative CT and a control DSA showed that the aneurysm was completely excluded. The angiogram was normal. There were no more neurological deficits after 2 months. 6 months after the first bleeding she had a spontaneous intracerebral bleeding with intraventricular inbleeding. The child was in coma. The angiogram (DSA) showed an aneurysm of the perlcallosal artery. The child died shortly after. The aneurysm belonged to the cryptic mycotic type. Although the aneurysms are usually fuslform a saccular form does not exclude the diagnosis. It is generally accepted in the literature that these patients should only be operated upon when the aneurysm(s) persist or after antibiotherapy or associated with o hematoma, abscess or in the case of a single peripheral aneurysms. When not operated upon control serial anglographles should be performed.

Poster 42

Poster 43

CAROTID ARTERY ANGIOGRAPHY: STENOSIS AUTOMATIC QUANTIFICATION.

C O N V E N T I O N A L (C) VS DIGITAL M Y E L O G R A P H Y A PROSPECTIVE C O M P A R A T I V E S T U D Y

J.M. Pumar, M. Alvarez, F. Hermida, J. Pereira y J. Vidal Hospital General de Galicia. Santiago de Compostela Esp~Sa.

C.Faubert (1), T.Scherb (2), E.Donauer (3), B.Kramann (I), U.Plepgras (2) Departments of Diagnostic Radiology (1), Neuroradiology (2) and Neurosurgery (3), Saarland-University, Homburg-Saar, FRG

In spite of the deveolo~xnent of non-invasive methods in the diagnosis of carotid arteriosclerosis, such as duplex-doppler, arteriography proves to be the method with more diacritic precision in the carotid stenosis valuation. By means of applying special programs in digital arteriography of supraortic trunks, we try to calculate stenosis degree and its repercussion in cerebral flow. We have carried out d±g±tal angiography of supraortic trunks in 40 patients with carotid stenosis. We have got color-flow arteriography images and curves of stenosis automatic quantification. By means of applying these programs in angiography, we have known, exactly, the geometric and densitometric stenosis percentage, as well as its hemodynamic repercussion which will helps us diagnosing these patients therapetutics.

(D):

Aim: (1) compare the diagnostic information (2) compare the relative reproductlbillty of anatomical structures. Material: Prospective study, 76 patients, av.age: 51,5 years old, 4 standard projections/patient x2 (identical conditions), Siregraph (Siemens) and Digiscan VAII (Siemens), evaluation by 4 experienced neuroradiologists in 2 sessions, Responder Operating Curve (ROC) analysis. Results: Sensitivity (C/D) 85,9%/87,4%, specificity (C/D) 64,43%/62,1%. Superiority of the digital technique for the cervicothoracic (N=I 1) and thoracolumbar (N=25). More specifically the postprocessed optimized (reconstruction filters, algorithms) digital films were statistically superior for spatial resolution of the nerve roots C7, C8, L1, L2, thecaI sac conus medullaris. Identical performance (ROC analysis) of both techniques for the other regions. Digital postprocessing did not improve the diagnostic information or reproduction of anatomical structures in cases when there was insufficient intrathecal contrast agents. Main advantage of the digital technique lies in the integration in a "PACS" system.

S 205

Poster 44

Poster 45

MR OF RADIATION INDUCEDMYELOPATHY J. Collignon, P. Flandroy, D. Martin, M. Delacollette, G. Dooms, G. Moonen, A. Stevenaert. CHU Sart Tilman, 4000 Liege, Belgium.

THREE TYPES OF SYRINGOMYELIA: COMPARISON OF EXPERIMENTAL AND CLINICAL RESULTS E.Donauer (l), C.Faubert (2/3)

Radiation myelopathy is a rare serious complication of radiotherapy. In spite o f many cases described in the l i t e r a t u r e , this lesion is rarely imaged by radiological and pathological studies. We describe a 62-year-old man who presented a "Brown Sequard Plus" syndrome two years after radiation therapy of a mediastinal tumor. The t o t a l dose delivered was 4500 C Grays in 10 fractions over 3 weeks. Subsequent X-rays and CT findings revealed a collapse o f the T8 vertebra with the presence of gaz during extension of the spine confirming the absence of metastatic invading and the vertebral necrosis. MR imaging was performed with a 1.5 T Unit. Precontrast T1-weighted images demonstrated a collapse and a hypointensity of the T8 vertebral body. The spinal cord was normal. On T2-weighted images, the cord showed a mild hypersignal in TS. Postcontrast T1weighted sequences revealed a hypointense ovoid intramedullary lesion with a peripheral enhanced rim. Moreover the specific c r i t e r i a = spinal cord included in the radiation f i e l d , neurological lesion corresponding to e x p o s e d medullary segments, metastasis or other medullary lesions ruled out, we suggest the radiation induced aseptic necrosis of a vertebra as a fourth argument to label the spinal cord lesion as radiation induced.

Poster 46 MRI IN SPINAL LUMBOSACRAL DYSRAPHISM Ph. Demaerel, G. Wilms, C. Raaijmakers, C. Verpoorten*, P. Casaer*, C. Plats**, A.LBaert Depts. Radiology, Paediatrics* and Neurology**, University Hospitals K.U. Leuven, Belgium The purpose of this study was to evaluate the contribution of MR/in lumbosacral dysrap.hi~. Thirty patients (13 O, 17 9) with a clinical spina bifida aperta (n=l 4) or occulta (n=16) were examined by MR/at 1.5 T. Alt patients underwent sagittal T1 weighted images and additional T2 weighted images were obtained in nine patients. Surgical correlation was obtained in nine patients. Eight examinations were performed after an operation for spinal dysraphism. A tethered spinal cord was the commonest finding, but an intraspinal lipoma was easily visualized too. Although the contribution of MRI was of great value, it was not always easy to depict details. Visualization of individual nerve roots, small fibrous connections and the exact configuration of the neural placode remained difficult. Nevertheless, MRI is the preoperative examination of choice in spinal dysraphism. Sonography remains important as screening and intraoperative imaging procedure.

Departments of Neurosurgery (1), Neuroradiology (2) and Diagnostic Radiology (3), Saariand-University, Homburg-Saar, FRG The findings of our own experimental studies on cots are surprisingly similar to those from MR in humans. We could differentiate three types of the so-called hydro- or syringomyelia. 1. The so-called hydromyelia, or syringobulbia, corresponds to experimental closure of the foramina Luschkae with cotton swabs, with continous dilation of the cavity along the total

spinal cord canal expecially into the cervico-medullary transition.

2. The hydromyelia is known from very deep-sitting tonsils of the cerebellum (Arnold-Chlari II) with a narrow central canal in crania-cervical transition and the balloon-like dilation of the syrinx under the narrow-ness corresponds to our experimental type of well-known kaolin hydrocephalus with a broad kaolin cuff in the subarachnoid space in the crania-cervical

region. 3. In hydromyelia as seen in Arnold-Chiari I or in patients withscars in crania-cervical transition with a narrow canal in the region of the first body of the cerebral spina a more slightly dilation of the central canal is observed by mild injection of kaolin in the cisterna magna. In all cases of dysraphic or experimentally induced syringomyella the cavities are distended along the central canal dorsally in the white matter of the dorsal column.

The cavities usually reach the total lenth of the spinal cord.

Poster 47 -

AN MR CLASSIFICATION

ITS THS~A~EI/[IC IMPACT.

V.C. Shah, S.B. Desai~ 0.3. ~K.E. Turel

Tavri,

P.

Ram,

A. K~hli~

MRI Centre, Breach Candy Hospital & P~--.~,-ch Centre, 60, B. Desai Road~ Bo~y~ India 1~Bc~oay Hospital & Rc-.~rch Centre~ Bombay ,India 21 patients with cranio-vertebral ano~slies e r e evaluated with MRI. All patients were studied on S i e i ~ Magnetem Superccr~k~ting Magret operating at 1.0 Tesla. Both T1 and T2 weighted =_4iin-echo images were obtained. All the patients were stLdied in neutral , flexion ~ d extension positions. A g r ~ of i0 patients were t~=ed as ~ontrols for the assessment of fc~-amen megrm~,, cer-1ical _~oire ~ cord and Lrair~tem diameters. The d i f f e r an~nalies were grouped tesed or, MR classification. The MR classification was devised b a ~ d on reducible vs. irreducible A.A.D., Mobile vs. fixed A.A.D., "Odontoid invagination"~ associated cord atrophy, associated other cord lesicr,s e t c , which is presented in this paper. The surgical a~,rc~zkes weFe determined on M R classification which ~=- fci~d to ~ v e positive and negative progr~istic predictive val~e.

S 206

Poster 49

Poster 48 ~'RI MYELITIS - EVALUATION OF 9 Ca%S£~B *S.B. Besai, V.C. Shah, O.J. Teezri~ P. Rex3, A. Koh!i Breech ~ _Wme~_~i~l & R--'-....-z,-'~:h C ~ t ~ , I~, India *Jaslc&; Hospital & FL~=_~archCentre, B~,bay~ India

VALUE OF COMPUTED TOMOGRAPHY IN THE WI-IIPLASH INJURY OF THE CERVICAL SPINE K. Cawka, J. Papa, Z. Doko, V. Nankovid, J. Stojanuvid Tree groups of patients having whiplash injuries of the cervical spine were studied using computerized tomography. The first

Nine patients with e~ute to suba~ute cord symptoms were sttdiEd with MRI. Fc~r underwent concurrent brain MRI stLdies for signs ~rd ~4~P~o~ of ~ e n d i ~ leJlms. All ~e s.-tLdied on 1.0 TESLA Siemens I~%£~OM st~ercorrJ~ztirg ~eQret. TI and T2 weighted images wee.-e c~tair~d. In f~-,, Gadc,linite, enhanced MRI's were obtained. Ti weigheJed i~e~es revealed a lor~ mixed signal inter~ity, primarily hypointen~Je lesion, with cord swelling, extending for longer length tb~i~~clinical level, which appreared ~heterc~=~neouslyhyperintenee on T2 weighted imeges. The zone of tre~sitic~ was wide ard ill defined. No as~_omiatedpseLdosyrinx was seen iv, these patients. Except in cre~ Gedolinium enhm~ced MRI'e s-k~3~d no enhancE,~ent o f c o r d le~ions. I n f e w , brain ~FtI ~ h o ~ d N r a ventricular deep white matter indi~_crete grey-white ~ t t e r h~erintenee !eaior~_. Fol!ow~p MRIe revealed disappearar~e ~f the~e les_icr~_ in five, who shc~ed clinical imprc~ement. In two, ~ho developed permanent neurological dE~ficit~ cord i~r~=mia ~-.d/~r m;~l~alacia were se~n. In two, who r~d Ece-d decc~preesion, t#e lesions and Signs totali,/ di_=appeared. Analysis and possible differer~tiaticr,of ~r yelitis frc~, cord ne~pla~=~ besed ~ MR ~indings i s pre~_~=~ted.

group comprised 62 patients with acute whiplash injuries examined within five days from trauma. The same group of patients was reexamined three months after the injury. The third group of 60 patients had chronic whiplash injuries. Measurements were performed in 30 male and 28 emale patients having acute injuries, and in 35 males and 25 females with chronic injuries, the age range being 18 to 70 yeaJs. Parameters measured in this study included sagitta] and transverse diameters of the spinal canal, retropharingea[ space d ameters and absorbance values of the paravertebra] musculature. The aim of this study was to examine the value of CT and CT myelography in the whiplash injuries as well as in

he analysis

of the pathomorphological changes occurring in the brains of these patients. The obtained results prove there is no staUstically significant difference in the measured parameters among female and male patients. On the other hand, a correlation between the patients' age and the spinal canal diameters has been established. In conclusion, it should be stressed that CT is a diagnostic method allowing a follow-up of pathological change~ from their onset till the formation of chronic lesions.

Poster 50

Poster 51

CHANGES OF THE SPINAL CANAL AND DURAL SAC ON THE CERVICAL MYELOGRAMS. THE POSSIBILITIES OF THE COMPUTER QUANTIFICATION

T H E S A L I N E P U S H T E C H N I Q U E IN THE E V A L U A T I O N OF M Y E L O G R A P H I C BLOCK: A N A L Y S I S OF 150 CASES W P Sanders, BA Mehta, E M spickler, R Silbergleit H e n r y F o r d Hospital, Detroit, Michigan, U S A

J.

Mihale,

O. B a r t k o ,

P. TurG~ni

1st Department of Neurology, Bratislava, Czechoslovakia

Comenius U n i v e r s i t y ,

A r e v i e w o f the measurements c o n c e r n i n g t h e quest i o n o f the d e v e l o p i n g bone s p i n a l c a n a l , i t s antero-posterior d i a m e t e r , the a n t e r o - p o s t e r i o r d i a m e t e r o f the d u r a l sac and t h e p l a n e of the dur a l sac , which were done p r e c i s e l y by means o f computer i n the d e t e r m i n e d p o i n t s and the lim~±ed areas. There is a convincing explanation for all the 26 persons with the normal spinal canal that the antero-posterior diameter of the dural sac decreased in retroflex[on in low cervical segments when compared with the neutral position. The results were found in retroflex[on also in the patients with the congenital stenosis of the spinal canal. By comparing an antero-posterior diameter of the dural sac in neutral position in the group of normal persons and in the group with the congenital stenosis, we have found out a significant diminution of the antero-posterior diameter of the dural sac in the latter group. Comparison of antero-posterior diameters of the dural sac in retroflection in the group of patients with the congenital stenosis of the spinal canal and in normal persons showed significant differences. In the group of normal subjects the plane of the dural sac decreased significantly in retroflex[on too. The reduction was more pronounced in patients with the congenital stenosis of the spinal canal.

W h i l e m o s t a u t h o r s b e l i e v e MRI is t h e p r i m e tool for the e v a l u a t i o n of spinal c o r d / c a u d a e q u i n a compression, t h e r e w i l l a l w a y s be p a t i e n t s r e q u i r i n g m y e l o g r a p h y for diagnosis. W h i l e some a d v o c a t e CI-02 puncture, w e p u s h c o n t r a s t a b o v e the b l o c k w i t h s a l i n e v i a l u m b a r puncture. We r e t r o s p e c t i v e l y r e v i e w e d 150 c o n s e c u t i v e c a s e s of n o n - s p o n d y l o t i c b l o c k in w h i c h t h e u p p e r level of t h e b l o c k s w e r e i d e n t i f i e d u s i n g t h e p u s h technique. In 147 of 150 o a s e s , ~ m y e i o g r a p h y c l e a r l y r e v e a l e d the u p p e r level of t h e block. Unsuspected m u l t i p l e b l o c k s w e r e all c o r r e c t l y i d e n t i f i e d in 8%. The only complication was a c c e l e r a t i o n of p r e - e x i s t i n g q u a d r i p a r e s i s , r e q u i r i n g u r g e n t d e c o m p r e s s i o n , w i t h full r e t u r n of function. Only 3 cases were u n s u c c e s s f u l , 2 due to p a i n d u r i n g injection, a n d 1 in w h i c h c o n t r a s t was n o t v i s i b l e a b o v e the block. All 3 h a d d i a g n o s t i c p o s t m y e l o g r a m CT scans. We c o n c l u d e that m y e l o g r a p h y via l u m b a r p u n c t u r e is quick, safe and e f f e c t i v e for p a t i e n t s w i t h s u s p e c t e d spinal canal compression, and m a y b e u t i l i z e d in cases w h e n M R I is not a v a i l a b l e or is contraindicated.

S 207

Poster 52 Title Authors

:

Institution :

Poster 53 Tuberculous Radiculomyelitis : Evaluation of myelography and CT myelogruphy. R.V. phac~e A.KoNi, V.K. Jain, R.B. Gu]raI, R.K. Gupta. Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, INDIA.

Tuberculous radiculomyelitis is still o n e of the important causes of paraplegia in some of the developing countries. Acid-fast bacilli can only rarely be isolated from the CSF and the diagnosis usually rests on clinical history and manifestations, laboratory findings in CSF and myelographic findings. Few descriptive reports are available on the myelographic appearance with water soluble contrast media in tuberculous radiculomyelitis. A retrospective review of 20 myelograms and ten CT myelograms in 13 patients with tuberculous radiculomyelitis was done with a view to describe in detail the radiographic features. Conventional myelographic findings included block (7/13), irregular subarachnoid space (9/13), filling defects (8/13), sluggish contrast flow (2/13), root thickening (3/13), and atrophic cord (2/1.3). CT myelogroohy peculiarly showed reduced contrast density in portions of the contra~t ring around the cord in affected region (6/7) and in addition demonstrated s e p t a and adhesions. Intravenous contrast CT was not found to be useful (2/2). Follow, up studies showed partial resolution (2/5), deterioration (i/5) and status quo of radiological findings (2/5). Conventional myelography q~peared to be the most important diagnostic tool for investigation and follow up in tuberc~ous t~diculomyelitis.

THE V A L U E O F F U N C T I O N A L C O M P U T E R - T O M O G R A P H Y O F THE C E R V I C A L SPINE IN E V A L U A T I O N OF W H I P - L A S H I N J U R I E S

Weinbergstr.

J. HAYEK(1), J. DVORAK(2) 160,Z~rich(1), K l i n i k e c h u l t h e s e

The method of functional CT deals with the measurement of the rotation of the cervical vertebrae in the axial plane after maximal possible forced rotation of the head to each side. Comparing the resulting values for each functional segment, the grade of hyper- or hypo- mobility to one side may be determined. The measuring technique uses the transversal foramina as landmarks, which consistently perform the rotation. For the rotation of the head,the landmarks are the occipital protuberantia and the nasal septum/vomer. In the normal condition the rotation values decrease subsequently from CO to C7. In whip-lash injuries,the main lesion is one of soft tissues ,among which the alar ligaments are important. Their vulnerability is also due to their lack of elastic fibres,which makes them more exposed to tears rather than stretching. Since they inhibit the rotation , a unilateral lesion to them would result in hypermobility between C0 and C2 to one side. This condition was studied by DVORAK on cadavers by experimentally severing the unilateral alar ligament and measuring the resulting difference of the rotation compared to the original intact situation. He found significant difference, which established later the basis for clinical application b y u s i n g the functional CT and developing accurate measuring methods (J.HAYEK). Our experience with some 400 cases in the last five years concludes that values till 5 ° difference in the segemntal rotation between left and right side, are normal;values up to i0 ~ are suggestive and those above I0 ° are conclusive of instability between cO and C2.

Poster 54

Poster 55

UNUSUALRADIOLOOICALFEATURESOF A DORSALDISK HERNIATION. CASEREPORT. d.d. Teruel 1, d.C. Vilaneva 1, X. 8erres 1, d. Barcelo I , A. Devalos2 and L.~nde5 Departments of 1 Radiology, 2Neurology and 3Neurosurgery, Hospital de Oirona "Dr. dmmp Truete", Oirona, Spain

MR OF LUMBAR SYNOVIAL CYSTS R Silbergleit, D J Q u i n t , SS Gebarski, EM Spickler, SC Patel Henry Ford Hospital, Detroit, MI

A 30-year-old moo had a sudden middle back pain when he was carrying a heavy weight. On neurelogicalexamination there was 8 mild paraparesis. Initial MRI on 12-weighted sequences showed signal increase in T6-7 level of the dorsal cord which was diagnosed as a ischaomic or dsmyelination disease.Itwas also noteda T6-7 thoracicdisk drop-out signal but thiswas misinterpreted.A new MRI examination performed six months later showed a thorscic disc herniation with spinal cord compression at the same level.

In order to establish e surgical appreach, a postmyetogrephic CT was performed; but failedto demonstrate an intraspinalmass. Afterwards, a new CT exam placing the patient in lateraldoc~Ibitusp~ition showed surprisingly that a partially calcified nucleus pulposus hod moved into

a centralpesterior location in touch with the spinal cord. The review of the previous C] scan donewith the patient in supine deoubitus position evidencedthe nucleus pulposus ocoupying.an anterior location between descendent aorta and vena cave, therefore proving the p(mterior disk displacement when functional manoeuvreswhere done. W e present the radiologicalfeaturesof this unusual disk herniation

(2)

Synovial cysts arising from the facet joints are rare causes of extradural masses. Almost all c a s e s a r e in t h e l o w e r l u m b a r spine. Post myelographic CT usually shows a typical posterolateral mass adjacent to a facet joint. The MR appearance is often more subtle. MR examintions of four surgically proven lumbar synovial cysts are presented with myelographio, CT, a n d p a t h o l o g i c correlation. Enhancement after Gadolinium-DTPA administration is identified in t w o c a s e s a n d hemorrhage i n t o t h e c y s t is demonstrated in o n e c a s e .

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Poster 56

Poster 57

THE BLOOD CIRCULATION ANALYSIS OF INTRASPINAL CANAL REGION USING DYNAMIC CT

MRI OF EPIDL~AL

SPINAL HEMATOMAS

AUTHORS: L. Lopez Ibor; M. de la Fuente; d.G. Martin

HID. MIZUNO 1, HIT. MIZUNO 1, TS. WATABE 1 , AT. HESHIKI 1, and CH. NAGASHIMA 2 Depertment of radiology I and neurosurgery2, Saitama Medical School, JAPAN To evaluate the blood circulation of intraspinal canal region, dynamic CT was appIied in 28 subjects including 4 normal volunteers. All subjects with hand bolus injection of contrast material were studied on Somatom DRH 2 ( Siemens ) for 5 rain. Scanning were performed every 10 seconds for 2 rain and a half minute for 3 rain. CT images, time-density curve, histogram, and circle histogram were reviewed. In normal volunteers, CT images, Time-density curve and histogram showed no significant changes during 5 min in spinal cord and adjacent organs. However, circle histogram, which hylightes the defined density levels within the localized circle, demonstrated intraspinal canal blood circulation with time-dependency between 40 to 80 HU range. Compressive ischemic spinal cord disorders due to OPLL and anterior vertebral dislocation showed severe epidural blood pooling and delayed blood circulation in the spinal cord between the above ranges. These abnormalities were completely improved by the simple laminectomy. In the patient with anterior spinal artery syndrome, no hylighted zones were visualized in the spinal cord between 30 to 80 HU ranges. In conclusion, dynamic CT using circle histogram is one of the useful method in the evaluation of intraspinal canal blood circulation.

Poster 58 Radionuclide Cisternography u s i n g S P E C T a n d 3DRendering H. Henkes*, G. Huber*, J. Hierholzer° , C. ~ujat*, T. Scherb*, W. ~ + , U. Pie;gras* Institut f~r N e u r c ~ o l 0 g i e , H ~ / S a a r * ; Radiologiscbe Elinik, UKRV/SC, Freie Universit~t Berlin°; Fa. P~DISOFT, Witten+ Radicr~/clide cisternography entails iruection of an appropriate radicp~ceutical into the subarachnoid space and imaging of the intracranial distribution. Main indications for this invasive ~tion are (1) the work up of hydrocephalus, (2) the search for C~F leakB, (3) to test, whether intracl~anialcystic lesions are ccrm~/hicatir~ cr not with the adjacent subarac~id space. ~he criteria for judgement of the ~ages are related to the distribution of the tracer 48 h after injection. The findings can be s u ~ z e d as (a) normal or (b) slow flow, (c) ventricular filling, (d) ~ t y flow, {e) block at any level, (f) as!mmstzy of distributionand (g) pcollng. A standard study includes anterior, poeterior and both lateral vie%~ 4-6, 24 and 48 hours after injection. The puzpoee of the pmesented study is to evaluate the feasibilityand diagnostic value of SPEC~ and subeequent 3D surface rendering in addition to ccr~m~ntional rectilineer CSF imaging. Patients and Met/~ode: cisternograph~has ~ perfoned in eight pati~ts (Indications: Hydrocephalus (4 pati~ts), pres~ CSF leak (3 patients), cystic intracranlal lesion (I patient). Four to six, 24 and 48 hctu~s after suboccipital injection of 55 ~ q Illln-DTPA or I U R ~ injectionof 260 ~ q 99~c-DTPA, conversionaland SPECr images were o b ~ , using a rc~atlng gam~ cairn with a ~APcolli~ator (AP~ 409~, ~ e c t e d to a APEX 415-computer. Via a t ~ hold-cross~ algorit/Tn, voltm~ric image generatlcm ~as done in an ,,increasing angle and fixed slicing depth" mode. Results: Oc~pared ~ith planar im~gee, SPEOT scans are superior (i) in the delineation of basal cisterns, especially in early scans; this is helpfull in patients with pooling due to CSF leak and in cystic lesicns nea~ the skull base. (2) In patients with hydrocephalus, ventricular activity is better to be di~erer/ciatedfrcrac c ~ t y flow by SPECT scatns. (3) 3D surface rendez/r~ ~ feasible in e ~ t i c ~ i s 6 ar~ 24 hrs after tracer application. (4) Planar ~ are advantageous in emmn~nations 48 hrs after tracer appicatlon, ~ h ~ SPECT scans are degraded by a low count rate. Ct~clusicnt SPECT imaging is a ~orthfull adjunct to planar cist~hy. 3D surface rendering from SPECT data is easily feasible, and givee high quality images. ~he esti~ntion of its diagnostic %~aluerequires further investigation.

Rodriguez; C.Perez Cuadrado. A. Ramos.

C l f n i c s La Paloma During t h e period from November 86 t o December 90 we have s t u d i e d w i t h MRI f o u r cases o f e p i d u r a l hematomas. One o f t h e p a t i e n t s was a c h i l d 4 years o l d who s u f f e r e d a closed trauma w i t h o u t evidence o f f r a c t u r e or v e r t e b r a l l u x a t i o n . I n the o t h e r t h r e e cases no e t h i o l o g i c f a c t o r could be found. The MRI appearance i s v a r i a b l e depending on t h e contents and e v o l u t i o n o f t h e blood (deoxyhemoglebin, methemoglobin, hemosiderin). The d e f f e r e n t i a l diagnosis i n c l u d e s e p i d u r a l m e t a s t a s i s , acute and chronic aracnoi~ d i t i s ( t u b e r c u l o s i s HIV, c y s t i c e r c o s i s ) and neoplasm such as chordomas

Poster 59 SONOGRAPHY

of

the

E. S t e i n e r , N. G r i t z m a n n Dep. of Radiology, Univ.

BRACHIAL

PLEXUS

of Vienna

Purpose: T h e p u r p o s e o f t h i s s t u d y is t o d e m o n s t r a t e the capabilities of high resolution sonography in evaluating the normal anatomy and pathologic conditions concerning the brachial plexus. Methods: 50 h e a l t h y v o l u n t e e r s a n d 22 p a t i e n t s w i t h partial or complete paralysis of the braohial plexus were examined on a digital sonography s y s t e m b y u s i n g 5 M H z to 1 0 M H z s e c t o r a n d l i n e a r probes. Results: The superficial part of the supraclavicular brachial plexus could be identified in a l l c a s e s . T h e f a s z i c l e s a p p e a r e d as p a r a l l e l o r i e n ted low echogenic bands between the anterior a n d t h e m e d i u s s c a l e n u s m u s c l e . O f 12 p a t i e n t s with traumatic rupture of the brachial plexus areas of marked attenuation and shadowing were observed in ii c a s e s . A d i s c o n t i n u i t y of the nerves themselves, however, could not be demonstrated. In 3 patients after neck dissection two hematomas and one lymphnode metastases compressing the nerves were shown. One patient with neurofibromatosis showed a 7cm large tumor. In 6 patients that had had radiation therapy, stab or compression injuries of the nerves no abnormalities could be found, Conclusion: The superficial p a r t o f t h e b r a c h i a l p l e x u s is reliably demonstrated by high resolution sonography. Some of the pathologic conditions affecting the nerves can be demonstrated.

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P o s t e r 60

P o s t e r 61

DIAGNOSTIC VALUE OF ULTRASOUND (US) IN EVALUATION OF PERIPHERAL NERVES (PN) AND THEIR LESIONS S.A.A.Qaiyumi, H.Milbradb S.Hussein, K.Weissenborn, B.Frank, H.Prokop, M.Galanski Departments of Diagnostic Radiology I, Neuroradiology, Neurology and Neurosurgery, Medical School of Hannover, FRG

TRACTION ~ E S O F T H E B R A C H I A L P L E X U S : RADIOGRAPHIC DIAGNOSIS BY ENHANCED COMPUTH3 TOMOGRAPHY (CT) AND MAG~TIC~I~AGING (MR) U.BI~ Department of Diagnostic Radiology, University of Freiburg, Freiburg, FRG

Thus far, imaging of PN has been rather limited. Our study was designed to evaluate the diagnostic value of US in PN of the lower and upper extremities. Material and Methods: We examined 25 healthy volunteers and 47 patients with various pathology to evaluate imaging features of normal and pathological conditions. We used Sonoline AC/SL1 US-machines (Siemens) and 7,5 MHz and 5 MHz transducers. Results: PN are hyperechoic bands with parallel internal structures and an echogenicity that is strongly dependent on the tilt angle of the transducer. All major PN could be demonstrated with exception of sural and peroneal nerves. Neuromas (n=12) were almost round, homogeneous echofree or hypoechoic with dorsal enhancement. Schwannomas (n=5) were often oval, homogeneous and hypoechoic. Neurofibromas (n=4) were oval or round, homogeneous and hyperechoic. Neurofibrosarcomas (n=2) were irregular, hypoechoic and inhomogeneous. Focal morphological changes could be found in following cases: carpal tunnel syndrome (n=10), ulnar sulcus syndrome (n=4), lipomatosis (n=2) and amputation of radial nerve (n=1). Compression of the nerves by surrounding masses were seen in Y cases. Summary: In summary US proved to be an easy, non-invasive and effective method to examine PN and their lesions.

P o s t e r 62 INFLUENCE OF INTRATHECALLY USED CONTRAST DYE (IOTROLAN) ON CEREBRAL CORTICAL ACTIVITIES. EEG FREQUENCY ANALYSIS. Y. URAKAMI.,H.SUMIE.,N.CRO.,K.YAGUCHI.,S.OKADA., Y. KURU. The potential neurotoxicity of lotrolan in cervical myelography was investigated in 30 patients using three criteria;clinical symptoms, EEG recordings with frequency analysis and CT scans of the brain. The CT observation informed how penetrated for the contrast dye into subarachnoid spaces. Clinical symptoms developed in two patients;one patient,whose EEG showed diffuse slowing after injection,complained for hallucinations 24hrs later, and the other,whose EEG showed abnormality (5-6Hz small spike and wave) after injection, had headache with severe EEG abnormality (HVS burst) 96hrs later. Two patients showed EEG abnormality (e.g.l.theta train in 0 area, 2.56Hz small spike and wave) without clinical symptoms. These abnormalities diminished within a week. In spite of fluctuations in vigilance,there was increased delta,theta and decreased alpha activities by quantitative EEG methods. We conclude that quantitative EEG methods are very important in the evaluation of the neurotoxity of contrast dye to CNS, especially among patients with parenchyma contamination,and that EEG recordings obtained 3-4hrs after injection can be used to predict adverse effects which likely to occur more than 24hrs later.

The exact radiographic localization of supraganglionic lesions of the brachial plexus provides important information for the prognosis and clinical management of these injuries. We report the results of enhanced CT-scanning and MR of the cervical spine in i0 patients with surgically proven root avulsions caused by traction injuries. All lesions were correctly diagnosed by enhanced CT-scanning (2 n~ slice thick-ness). The techniques used i n M R (0.23 T unit) were conventional sequences and RARE imaging: 90 % of the neural lesions were identified. RARE imaging, a fast imaging method, is an ideal method and prcmises to be most useful and sufficient for establishing the c o r r e c t d i a g n o s i s in t h e s e cases.

P o s t e r 63 EFFICACYANDCLI~C~ S h r ~ OFGADO~gn)OL (PROHANCE, SQUIBB DIAGNOSTICS) AS A NEW NEUROLOGIC NON-IONIC MR CONTRAST AGENT M.A. Mikhacl Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois PURPOSE: Four hundred eleven patients with suspected intracranial or spinal disease were included in multicenter study to evaluate the clinical safety and efficacy of a new neurologie nonionic MR contrast agent, Gadoteridol (Prohance, Squibb Diagnostics). MR scans were obtained for every case before and after intravenous injection of 0.1 mmol/kg of Gadoteridol. This presentation, summarizes our experience of 32 cases studied in our institution (16 Brain and t6 Spinal cases). METHODS: Patient monitoring included history, physical examination, vital signs, complete blood and serum assays, and urinalysis within 24 hours before and after intravenous contrast administration. RESULTS: Nonblinded image evaluation has shown that post-contrast studies provided more diagnostic information in 75% (12 cases) of brain lesions and 78% (13 cases) of spinal cases; showing the activity of inflammatory changes, the extent of invasive tumors, active and nonactive multiple sclerosis plaques, and the acute from old infarction. Enhanced MR studies could easily detect small and large pituitary tumors and acoustic neuromas. They showed brain and spinal metastatic lesions even when nonenhanced T2-weighted scans were negative. No serious adverse reactions were recorded. Only transient metallic taste was noticed in one case, and stinging at the site of injection in two persons. CONCLUSION: The use of Gadoteridol injection, as a nonionic MR contrast agent, is demonstrated to be safe and provides essential diagnostic information in neurologic diseases, which cannot be obtained from nonenhanced MR studies. Such information can change the diagnosis and subsequently the treatment of these patients.

S 210

Poster 64 CAVERNOUS SINUS : MR ASSESSEMENT A N A T O M I C AND M I C R O S C O P I C C O R R E L A T I O N S J.P. PRUVO, N. MARTIN~ X. LECLERC~ I. KRIVOSIC, J.P. FRANCKE.

WITH

To better define the MR a n a t o m y of the cavernous sinus, the autors correlate normal MR Studies with anatomic and histologic sections of the Cavernous Sinus. MR Scans were performed in 60 patients using 0,5 T and 1,5 T Magnet Units

(GE). Images were obtained using pre and post-contrast T1 w e i g h t e d SE Sequences, w h i c h were correlated with images a c q u i t e d with pre and p o s t - c o n t r a s t fast imaging techniques. These images were compared with similar anatomic sections obtained from 20 frozen cadavers and with macroscopic and histologic sections obtained from ]00 cadaver specimens of the p a r a s e l l a r region. These correlations show that MR a c c u r a t e l y d e m o n s t r a t e s the n e r v o u s (III, Vl, VI) and dural structures of the lateral wall of the Cavernous S~nus, w h e r e a s fastimaging sequences finely depict the venous spaces of the Cavernous Sinus.

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Posters WFITN Poster 65

Poster 66

VASCULAR ARCHITECTURE OF CEREBRAL ARTERIOVENOUS MALFORMATIONS W. Miiller-Forell, A. Valavanis Dept. of Neuroradiology, University Hospital of

EVALUATION AND ENDOVASCULAR TREATMENT OF INTRANIDUS ANEURYSMS IN CEREBRAL AVMs. MP Marks, B Lane, GK S t e i n b e r g Stanford U n i v e r s i t y Medical C e n t e r

~.urich

Cerebral arteriovenous m a l f o r m a t i o n s (AVM's) are the most frequent specifity of cerebral m a l f o r m a tions, as w e l l as the m o s t f r e q u e n t c a u s e of intracerebral h e m o r r h a g e . W i t h r e g a r d to indication and therapeutic decisions recent knowledge of m i c r o n e u r o s u r g e r y and neuroradiology lead to the necessity of precise morphological and haemodynamical diagnostic m a n a g e m e n t of the AVM's. MRI and superselective neuroangiographic investigations of 228 p a t i e n t s w i t h c e r e b r a l AVM's were analysed with regard to topography, morphology, v a s c u l a r a r c h i t e c t u r e and s i g n s of increased bleeding risk. MRI proved to be highly efficient in defining topography of the l e s i o n s c o n c e r n i n g sulcal, gyral or central localisation of the nidus. Additionally it p r o v e d to be m o r e s e n s i t i v e in detecting A V M - i n d u c e d p a r e n c h y m a l c h a n g e s , e s p e cially h e m o r r h a g e s , w h i c h w e r e s e e n in 55% of all patients (versus 39% with clinically known hemorrhage). S u p e r s e l e c i t v e n e u r o a n g i o g r a p h y e n a b l e s complete e n d o v a s c u l a r m a p p i n g of the AVM's and gives n e w i n s i g h t into the v e n o u s d r a i n a g e p a t terns, e s p e c i a l l y its u n e x p e c t e d h i g h i n c i d e n c e of associated venous changes as stenosis or combinations w i t h v a r i c e s . At least t h i s f i n d i n g seems to be an i n d i c a t o r of i n c r e a s e d b l e e d i n g risk. Correlation of MRI and n e u r o a n g i o g r a p h y of each i n d i v i d u a l c a s e f o r m s the b a s i s for any therapeutic decision and treatment planning.

Previous work h a s s u g g e s t e d t h a t i n t r a n i d u s a n e u r y s m s in cerebral AVMs correlates strongly w i t h a history of h e m o r r h a g e . This s t u d y evaluated t h e p r e s e n c e of i n t r a n i d u s a n e u r y s m s a n d their e n d o v a s c u l a r therapy. 125 p a t i e n t s with intracranial AVMs were s t u d i e d with bip l a n e angiography. 79 of 125 (63.2%) h a d history of h e m o r r h a g e . 15 p a t i e n t s (12%) d e m o n s t r a t e d i n t r a n i d u s a n e u r y s m s ; 5 were suitable c a n d i d a t e s for e n d o v a s c u l a r therapy. Embolization w a s performed b y super-selective catheterization with either flow directed or guide-wire directed catheters, utilizing liquid a d h e s i v e (N-butyl cyanoacrylate) or PVA particles. A statistically higher incidence of h e m o r r h a g e w a s f o u n d in t h e p a t i e n t s with i n t r a n i d u s a n e u r y s m s (p < .001). 15 of 15 (100%) with i n t r a n i d u s a n e u r y s m s h a d a history of bleeding. 64 of 110 (58.2%) w i t h o u t i n t r a n i d u s a n e u r y s m s h a d a history of bleeding. A total of 19 i n t r a n i d u s a n e u r y s m s were s e e n in t h e 15 patients. A n e u r y s m s ranged in size from 0.2 c m to 1.3 c m ( m e a n 0.8 cm). The 5 p a t i e n t s embolized h a d total of 7 i n t r a n i d u s a n e u r y s m s . Embolizatlon t h r o m b o s e d all 7 a n e u r y s m s . Patients were followed-up p o s t embolization for 1-22 m o n t h s ( m e a n 9). 2 h a d radiosurgery a n d 3 h a d conventional microsurgery. O n e p a t i e n t h a d repeat h e m o r r h a g e . I n t r a n i d u s a n e u r y s m s correlate strongly with h e m o r r h a g e . E n d o v a s c u l a r t h e r a p y is a n effective modality for achieving t h r o m b o s i s of t h e s e a n e u r y s m s . Since radiosurgery h a s a long latency period between t r e a t m e n t a n d AVM obliteration, embolization m a y help to r e d u c e r e c u r r e n t h e m o r r h a g e in this time period.

Poster 67

Poster 68

ENDOVASCULAR TREATMENT OF INTRACRANIAL DIRECT ARTERIOVENOUS FISTULAE, Lylyk P, March AD, Kohan GA, 6iacobbe HL. Institute de investigaciones Neuro16gicas Raul Carrea, Bs. As., Argentina.

INTRACRANEAL ARTERIOVENOUS MALFORMATION EMBOLIZATION: REVIEW OF 36 CASES.

Six cases of intracerebral direct arteriovenous fistulae (DAVF) treated by endovascular tecniques are presented, Four cases ocurred in infants whereas the rest were adults. All cases had giant venous variees. Infant cases showed development retardment, chronic brain hypoxia and venous engorgement which ameliorated after fistula occlussion. One of the adult cases was diagnosed after brain hemorrhage, although a giant temporal venous varix was present. All procedures were carried out under neurological and/or neurophisiological monitoring and occlusion tests were done before permanent occlusion. Arterial hypotension was induced during the procedures and in the Following 72 hours, Embolic agent, included balloons, microcoils, IBCA and Guglielmi detachable coils, DAVFs exhibit high flow, venous hypertension and giant venous varices. When shunt volume is excessively high. chronic brain hypoxia and related neurological lesions may develop, lhis being probably the cause of infant presentations. Hemorrhage as a presenting sign is rare but possible so treatment must no be delayed once diagnosis has been made. Endovascular techniques are parlicu]ar useful due to their ability to achieve occlusion at the site of the fistula and observe lhe inmediate hemodynamic consequences of the abrupt change of flow determined by shunt interruption. Occlusion tests under neurological and neurophysiological monitoring are mandatory in this sense.

AUTHORS:L. Lopez I b o r ; C. D i a z . Clfnica

M. de l a Fuente;

B.Anciones;

La Z a r z u e l a .

36 p a t i e n t s w i t h an a r t e r i o v e n o u s m a l f o r m a t i o n were t r e a t e d by means o f an s u p r a s e l e c t i v e i n t r a c r a neal embolization, using polimerized Glue-material or Ivalon-particles (5 c a s e s ) . Localization of arteriovenous-malformation was as follows: 28 h e m i s p h e r i c a l , a f f e c t i n one o r more l o b e s (frontal, parietal, t e m p o r a l and o c c i p i t a l ) , either cortical or subcortical. 2 deep, a f f e c t i n g t h e basal ganglia. 4 i n p o s t e r i o r f e s a e : 1 i n brainstem 1 i n s u p e r i o r v e r m i s , 2 i n v e r m i s and c e r e b e l l u m . 2 a f f e c t i n g e. c a l l o s u m and G a l e n o - V . Results about treatment with endovascular embolization, either alone, or in combination with radiosurgery or surgery are discussed.

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Poster 69

Poster 70

M R I IN D I F F E R E N T I A T I N G E M B O L I Z A T I O N A G E N T F R O M B L O O D CLOT IN C E R E B R A L A R T E R I O V E N O U S M A L F O R M A T I O N S (AVMs) F O L L O W I N G E N D O V A S C U L A R SURGERY L.Prayer, D.Wimberger, R.Stiglbauer, J.Kramer, B.Richling, G.Bavinszki, Th. Czech, E.Schindler and H.Imhof; MR-Institute and Departments of Radiology and Neurosurgery, University of Vienna

~ D D V A ~ U L ~ TREATM~T OF c m m u u ARTmlOVBOUS MALFORMATIONS -CmPARISON BroWSER PREOPEraTIVE BALLI]Oi~~CLtISI~ OF FEEDING ARTERIES AND EMI~]LI~TIONS OF NIDUS L Sugimt0 ~~, A. Hy0d0*~, Y.Mats~am *~, T. Ymhizawa '), T. En0mt0 '>, Y. Y0shii~,T.N0se I~ , W.Takiz~, ~ lwata3> Department of Near0surgery, University of Tsukuba, Tsukuba, Japan*~ Department of Neuresurge~, University of Kyoto, Kyot~, Japanz~ Depar~cment of Surgical l~esear~, National Cardio Vascular ~nter,

After superselective endovascular surgery of cerebral AVMs only t e r r i t o r i e ~ filled with embolizatlon agent are o c c l u d e d definitely; merely thrombosed vessels, however, could recanalize. The purpose of this study was to determine the capacity of MRI in the a s s e s s m e n t of posttherapeutically not p e r f u s e d A V M t e r i t o r r i e s . In 35 patients with cerebral AVMs 64 MR examinations (1.5 tesla; T1- and T2-weighted SE sequences (TR/TE: 700/15-22; 2000-2500/15/80-90); two planes; 3-5mm slices; 0-50% interslice distance) were performed after embolization with n-butyl-2-cyanoacrylate ("histoacryl")-lipiodol. Assessment was made regarding e m b o l i z e d and thrombosed nidus territories. A f t e r endovascular surgery, in 9 out of 35 patients A V M n i d i w e r e not p e r f u s e d ; in 5 of t h e m complete embolization was ascertained, whereas in 4 both embolized and t h r o m b o s e d zones were found. In the remaining 26 patients, embolized and thrombosed nidus parts as well as still perfused territories were seen. In follow-up examinations, recanalization of thrombosed vessels was proved in 6 patients. In M R examinations following endovascular surgery, characteristic signal patterns of embolization agent as well as of blood clot could be recognized. Methemoglobin could not be d i f f e r e n t i a t e d from histoacryl-lipicdol, whereas deoxyhemoglobin and hemosiderin were easily distinguished. Hence, time interval between therapy and M R e x a m i n a t i o n has to be considered in order to differentiate between embolized and therefore definitely o c c l u d e d regions and merely thrombosed A V M nidus territories which could be recanalized.

Poster 71 PERCUTANEOUS EMBOLIZATION WITH FLOWER PLATINUM COILS IN 4 BASILARARTERY TIP ANEURYSMS. A.M.Goulao, J.M. Cannas, G.J. Branco Department of Neuroradiology - Egas Moniz Hospital Lisboa - Portugal PURPOSE: Obliteration with flower coils of aneurysms of difficult or dangerous surgical approach. MATERIALS AND METHODS: 4 patients with medium-sizebasilar tip aneurysms, aged between 33 and 40, were treated with one or several flower coils. In one of them 2 Hilal coils have also been inserted. RESULTS: In all cases we achieved thrombosis of the dome of the aneurysms: In two there was complete and in one near complete obliteration. The last case with only seventy percent occlusion is scheduled for reembolization. Two of the patients have a follow - up of i year. No permanent complications arised related to the procedure, and the patients are clinically in good condition. One patient had a transient vasospasm with cortical blindness lasting 6 hours. CONCLUSION: By this preliminary experience of ours we a&~t that thrombosis in these aneurysms may be achieved by a favourable spatial distribution of the coil's spires inside the lumen. Also the presence of Polyester fibers in these coils may be important.

Suite, &panS> Twenty patients underwent endovamcular treatment for cerebral arteriovenous malformation Oil). In initial ten patients, preoperative occlusion of feeding arteries were performed using detachable balloon catheter. In the next ten patients, embelizatioes of nidus of the AW were performed using liquid ethylene vinyl alcohol co-pely~erer polyvinyl alcohol particles through Traeker~18 catheter or leak balloon catheter.We compared the effects and the problems between preoperative hal loon occlusion of feeding arteries and e~bo]ization of nidus. Both bailcon occlusion and embo|izatien were performed after provocative test.There was no complication assooiated with balloon occlusion, but there were a major and four minor neurological deficits among twenty one procedures of embolization.Though the balloon occlusions were efficient, some of them were not so effentive because of the incomplete flow reduction of the AVM.The effect of embol ization was mere prominent than that of balloon occlusion. In one case the AVM

was disappeared completely only by embolisation. In conclusion, preoperative balloon occlusion is relatively safe and this method is effective in some cases.Bowever, it is incomplete in some ether canes.On the other hand, embolization is more effective for the treatment of the A~, but i t should be performed very carefully in order not to cause any complications.

Poster 72 INTI~V~CULAR SURGERY OF INTRACRANIAL USING NEWLY DE--LOPED ELECTRICALLY NO-COLLAR BALLOON S.Usami, K.Oguchi, S.Matsui I Dept.of Pharmacology and Neurosurgery School of Medicine,Showa University

AI~RYSM DETACHABLE

~,

Various types of detachable balloons(DBs) for the intracranial aneurysm(AN) have been studied. However, few of them are electrically detachable. We have develolmmd a no-collar DB which preserves the parent artery, gives ideal A N e m b o l i z a t i o n , aund c a n I>~ d e t a c h e d electrically without leaving any collars. Methods: Based on the angiographical studies in 107 patients, we determined that an ideal DB w a s 1.4mmm i n di~umeter a n d 4 . 0 ~ m long, made of silicone supplied from Dow corning JAPAN. Using this no-collar DB with an electrical detaching system, we treated i0 d i f f i c u l t and inoperable cases. Results: We successfully treated 7 cases. In two unsuccessful c a s e s , /iN r u p t u r e c o u l d n o t l~m prevented l~mcause i n o n e c a s e , t h e a c c e s s to t h e fiN w a s e x t r e m e l y difficult due to the previous surgery the patient had; in another case, treat~nt of vasospasm induced too much blood flow increse. One last case died of recurrence of AN rupture 6 months later because of imcomplete embolization. Conclusion: We confirmed that this novel DB with an electrical detaching system we developed has several advantages over the conventional DB.

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Poster 73

Poster 74

ENDOVASCULAR TREATMENT OF TRAUMATIC ANEURYSM OF CERVICAL CAROTID ARTERY FY Tsai, CJ Meoii, KM Aifieri, J Baker. University of Missouri-Kansas City, School of Medicine Truman Medical Center

INTRACAVERNOUS CAROTID ARTERY BALLOON OCCLUSION FOR GIANT ANEURYSMS V Vasquez, A Aymarcl,A Laurent, A Redondo, M Khayata, R Beaujeux, JJ Merland Dptof lntsrventiona!Neumradiology,Ladboisl6reHospital, Pads,France

Carotid artery injury may be a part of, or independent to, closed and/or penetrating t r a u m a to the head and neck. The injury may lead to occlusion of the artery, bleeding, aneurysm, fistula or stenosis. Traumatic aneurysm of the cervical carotid artery is probably the most difficult situation to be encountered among the varieties of carotid artery injury. Due to nature of the site of this traumatic aneurysm, it is not accessible by direct surgical approach. Endovascular therapy is probably a choice for this entity. Traumatic aneurysm may enlarge in size and it may not be formed until sometime later. It may become a source of thrombus formation leading to stroke or bleeding from rupture of an aneurysm. Detachable balloon embolization is the primary choice. However, miorocoil may be needed to replace the usage of a detachable balloon due to the size and thrombus in the aneurysm. We wish to present our experience in detail.

Poster 75 EMBOLIZATION OF A GIANT CORTICAL TRALrMATIC CEREBRAL PSEUDO ANEUHYSM IN A CHILD WITH NBCA - CASE REPORT ILL Piske (i); E de Olivelra (2); LA Carone (2) l-Med Imagem - Hospital Beneficencla Portuguesa - Sao Paulo SP - Brazil 2-1nstituto Neurol6gico de Sao Paulo - Sao Paulo SP Brazil Traumatic cerebral pseudoaneurysm is a rare entity, spe cially if giant, distal and occuring in children. Its tre atment is quite controversial. In this paper we present the successful treatment of a giant traumatic pseudoaneurysm of a distal branch of the posterior cerebral artery in a 10 month old child by endo vascular approach. Through a superselective catheterization the posterior temporal artery was occluded just proximal to the aneurysm with n-butyl 2 cyanoacrylate (NBCA). Although the method proved to be quite satisfactory we could not find a similar case reported in the literature. Indication, risks and technical aspects of the proced~ re are presented and discussed.

We evaluated the results of carotid occlusion in the treatment of intracavernous carotid giant aneurysms before and after the institution of cerebral blood flow monitoring CBFM). Retrospective review of all patients undergoing carotid occlusion revealed 32 patients with intracavernous carotid artery giant aneurysms. Group A t980-1987 (before CBFM) and Group B 1987-1990 (with CBFM) were identified. Clinical and angiographic features were reviewed prior to and after treatment. Endovascular treatment included test occlusion under neuroleptic analgesia with clinical and angiographic assessment of collateral circulation (Group A) and additionally in Group B, CBFM and transcranial doppler prior to definitive closure. Current criteria for successful test occlusion include perfect clinical tolerance, a minimal decrease in hemispheric CBF, and complete angiographicalty demonstrated collateral circulation. Group A complications: 1 permanent and 4 transient neurologic complications. Since, five patients did not meet our criteria and required an EC-IC bypass before successful occlusion. Mean follow up was 4.7 years. 32 patients treated were cured of their aneurysm with symptom resolution (except two with persistent oculomotor nerve deficits) Balloon occlusion for ICC-GA is effective and reliable form of treatment. With CBFM, the dsk of neurologic deficit is diminished. If test occlusion is not tolerated, an EC/IC bypass is indicated.

Poster 76 LONG TERM FOLLOW-UP OF PATIENTS WITH INTERNAL CAR(YI~ ARTERY ANEURYSMS USING MRI M.A. Mildaael Evanston Hospital-McGaw Medical Center of Northwestern University Evanston, Illinois PURPOSE: To evaluate the value of MR imaging in long term follow-up of patients with cranial aneurysms following gradual surgical occlusion of the common carotid artery in the neck. MATERIALANDMETHODS: Seventeen patients with large aneurysms (more than 5 mm) arising from the carotid siphon and cerebral branches, diagnosed by MR and proven by angiography, are included in the present study. The patients underwent surgical gradual occlusion of the common carotid artery with an adjustable clamp in the neck. as a treatment for their intracranial aneurysms. Accurate follow-up was possible in 16 of these patients. CT scans and angiograms were obtained on all patients and MR was obtained on 6 of these patients before surgery. Follow-up MR scans were obtained on all patients with variable time intervals varying from a few months to 3 years. RESULTS: MR studies were done using spin-echo technique to obtain axial, sagittal and coronal slices for the head with thin slices through the region of the sellar/parasellar areas (3 nnn thick and no gaps). The aneurysms (greater than 5am) were visualized in all cases. Morphological changes in the size of the aneurysms were followed-up by the subsequent studies. Aneurysm size, mural thrombus, turbulent blood flow and surrounding brain changes were clearly seen. Most aneurisms became partially thrombosed, though some were still totally patent years after carotidligation. CONCLUSION: We believe common carotid ligation is a safe and effective treatment for selected internal carotid artery aneurysms when their size is more than 5 ram, and when the age of the patient is not optimal for more aggressive treatment. We present evidence that MR is an excellent means to assess these patients postoperatively and for long-term follow-up without the invasive angiogram.

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Poster 77

Poster 78

ENDOVASCULAR TREATMENT OF INTRACRANIAL ANEURYSMS IJSING 6UGLIELMI DETACHABLE COILS: EARLY EXPERIENCE. Lylyk P, March AD, Suglielmi G, Vifiuela F, Kohan 6A, 6iacobbe HL, Institute de Investigaciones Neurol6gicas RaOl Carrea, Bs.As.,Argentina

CLINICAL EVALUATION OF PREOPERATIVE EMBOLISATION OF MENINGIOMAS

Electrolitically detachable platinum coils represent a valuable alternative for the endovascular treatment of intracranial aneurysms, During the past year, endovascular ociussion using this new technique was attempted in 9 patients. All patients were adults, nine of them with the aneurysm as single lesion and one associated with an AVM. Seven of the aneurysms were giant, one medium-sized and one small, Five aneurysms belonged to the anterior circulation and four were posterior, SAH was the initial sympton in six cases, whereas symptoms deriving from mass effect were prim~ily observed in lhe remaining cases, Arterial vasospasm was present during treatment in two cases, Outcome included6 complete occlusions,Isubtotalocclusionsand failure to reach the aneurysm in 2 cases. Detachable coils seem particularly well adapted for the treatment of intracranial aneuryams, overcoming manyofthe problems associated with other methods, Nevertheless, tortuous vessels and the presence of" vasospasm remain a problem.

18 vascularised lesions out of 95 operated intracranial meningiomas were embolised with PVA particles using microcatheter technique. Average period elapsed until surgery was ll days. Evaluation was carried out on the basis of comparison of pro- and postembolisation anglo pictures and CT scans, as well as on the analysis of surgical reports, of anaesthesia charts assessing amount of transfused blood, and of histopathological examination. Angiographic criteria of consideration were: !./ filling of tumour feeders, 2./ signs of circulatory disturbances (arterial spasm, decreased flow velocity) 3./ change in tumour staining. On postembolisation CT scans a survey was undertaken for alterations in enhancement and possible signs of tumour necrosis. CT was usually performed prior to operation. In cases of external carotid supply, when potential of embolisation could be expected as most promising, anglo and CT findings squared well with clinical observations both in good and less successful cases. When internal carotid feeding associated with multicompartmental tumours was present extent of embolisation was limited, and assessment of efficacy proved controversial.

Poster 80

Poster 79 ENDOVASCULAR ~ B O L I Z A T I O N OF THE H E A D A N D NECK: EXPERIENCE IN 30 PATIENTS

l.Szikora, F.L~nyi, Gy.Oe~k National Institute of Neurosurgery, Hungary

OUR

F.Briganti,G.LaTessa,A.Manto,F.Caranci,F.Smaltlno,R.Elefante. Istltuto di Scienze Radiolegiche II Cattedra. Cattedra di Neuroradiologia. Universlta' degli Studi di Napoll. Ii Facolta' dl Mediclna e Chirurgla. Purpose of Study We have reviewed 30 patients with intracranial and extracranlal lesions supplied by the external carotid artery treted by embollzation during last 3 years. Method Selective angiography and embolization was performed in 29 cases with femoral approach and one case (carotid-cavernous fistulas) by surgical exposure of the superior oftelmic vein.Ne~roleptic analgesia was used in all cases.Preoperative embolizatien was performed in t w e n t y one cases (twelve angiofibrema six meningiomas,two paraganglioma,one dural fistula) with particulate agents such as polyvlnil elcaohol (RVA). A variety of embolic agents w a s used to embolize the other lesions, depending on location and flow characteristics: Isobatyl-2-cyanoacr~late (IBCA) was used to embolize one dural fistula.Miorecoils were u s e d in one carotid-cavernous fistula, PVA and microcoils in two facial ArM and three dural arteriovenous flstulas. In one facial ArM PVA was used and the recurrence of malformation was observed at six month. Results and Conclusion In preoperative embolization we had a good devascularizatlon of the lesions and no complications d u r i n g the procedure.This is due to the superselective c a t h e t e r i z a t i o n and embolizatioa to prevent the passage of particulate agents in the normal anastomoses between external and internal carotid artery. N e w microooils with or without a particulate or liquid agent are a safe method of endovascular treatment.

ENDOVASCULAR TREATMENT OF EXTRACRANIAL VERTEBRAL ARTERI0VENOUS FISTULAS. D.L. Fiore, P.Roseano*, K.Pardatseher**, A. Rotilio °, G.F. Buia °° Department of Neuroradiology, Department of Radiology*, Department of Neurosurgery °, Department of Cardiology °° Padova. Neuroradiology** - Catanzaro. Vertebral fistulas are sustained by anomalous comunications between vertebral artery and neck veins. Mostly of the vertebral fistulas are traumatic; the others can be congenital or spontaneous. Generally fistulas are asyntomatic and are associated with other vascular anomalies; spontaneous fistulas associated with vessel wall alterations like aneurysms and pseudoaneurysms linked with Fibromuscular Dysplasia (FMD) or Neurofibromatosis, start with unexpectedly clinical symptoms. At the moment vertebral fistulas are effectively managed by endovascular detachable balloon therapy. One congenital and one spontaneous fistulas are with the complete reduction of the initial symptomatology are the two cases reported by the Authors. Casel: Young female affected by isthmian eoarctation of aorta (previously surgically treated) associated with right vertebral artery fibrodysplasia. Case 2: Child patient with congenital right cervical bruit Both cases were successfully trated by endovascular occlusive procedure with Hieshima Balloons filled with non ionic contrast agent (IOPAMIRO).

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Poster 81

Poster 82

EMBOLIZATION IN HIGH-FLOW ARTERIOVENOUS MALFORMATIONS OF THE FACE Komiyama M, Yasui T, Yagura H, Fu Y, Nagata Y, Tasura K Department of Neurosurgery, Baba Memorial Hospital, Sakai, Osaka Japan Five patients with arteriovenous malformations of the face (4 men and 1 woman with an age of 11-38) were treated by selective embolization through the feeding pedlcles with polyvinyl alcohol (PVA) particles. The lesions were located at the cheek and the upper lip (2 cases), at the ear (2 cases), and at the hemi-face (i case). Immediate gross angiographical obliteration was obtained in 4 cases with marked reduction of the arteriovenous shunt in the fifth. Clinical symptoms including bleeding, swelling, pulsations, bruit and disfigurement improved in all the patients followed up for a period of 6-21 months with a mean of 12 months. There were no procedure-related complications except for local pain, swelling, and low-grade fever which usually lasted 3-7 days. PVA particle embolization, without surgical resection, though palliative could be useful in selected cases. Its advantages include: selective access to the lesion sparing the normal tissue; easy repeatability; performance under local anesthesia permitting continuous neurological monitoring; provocation test using xylocain for possible cranial nerve damage; preoperative reduction in size and vascularity. The classification and diagnosis of congenital vascular malformations is briefly reviewed and treatment discussed.

OCCLUSION OF IPSILATERAL OCCIPITAL ARTERY FOR IDIOPATHIC TINNITUS

Poster 83

Poster 84

PREOPERATIVE EMBOLIZATION OF INTRACRANIAL MENINGIOMAS: ANGIOGRAPHIC AND SURGICAL CORRELATIONS

THE VALL~ OF PREOPERATIVE EMBOLIZATION OF PARAGANGLIfAMAS P.C.Shetty, D.Reddy, M.W.Burke, G.E.Guy, D.Kastan, R.Sharma, T.H. Burke Henry Ford Hospital, Detroit, USA

G.E. Klein, J. Lammer, F. Waltner, egger, F. FlGckiger, M. Mokry

BA Mehta, WP Sanders, TH Burke Henry Ford Hospital, Detroit, M i c h i g a n U.S.A. Purpose: We describe 5 cases of idiopathic tinnitus, in w h i c h high resolution CT, MRI and superselective angiography revealed no anatomic or pathologic finding to account for t h e tinnitus. Methods: 5 adult tinnitus patients u n d e r w e n t superselective angiography of internal carotid, vertebral and individual branches of ipsilateral external carotid arteries. If no lesion was found, the ipsilateral occipital artery was occluded using suture material and/or platinum coils, being careful to bridge that portion of the occipital artery that u s u a l l y gives rise to branches to the middle ear. Results: There were 4 complete successes, and one patient with moderate reduction in tinnitus. There was only one complication, a questionable allergic reaction consisting only of hives, becoming visible 48 hours a f t e r embolization. Conclusion: Coil/suture occlusion of the ipsilateral occipital artery may be effective in treating tinnitus in those patients w i t h o u t an identifiable structural cause.

K.A. Haus-

Purpose: Preoperative embolization of intracranial meningiomas should facilitate their total resection. The aim of this study was to evaluate the efficacy of embolization in tumors with external CAS only and those tumors with external and internal CAS. Methods: In 90 patients a preoperative embolization was performed. After CT and/or MR examinations embolization was performed in the same session as the diagnostic angiography. We routinely used 3 French Microcatheters with steerable guidewires for superselective angiography and embolization. As embolic agent, polyvinyl alcohol foam (PVA) particles were used. Results: Marked hemorrhage during surgery occured only in one of 47 patients with only external CAS. In five of 43 patients with internal and external CAS significant intraoperative bleeding occured, 4 of them had predominantly internal CAS. Conclusion: The use of Microcatheter in combination with DSA enables an effective and safe embolization. The preoperative embolization appeared to be very useful in all patients especially in large tumors with predominant external CAS and in skullbase meningiomas.

The application of the reconstructive vascular surgical procedures to the treatment of carotid paraganglic~as has made resection the method of choice and has produced an excellent cure rate. However, it has not removed some of the technical problems presented by excesilary vascular, adherent or bulbky lesions. Large hypervascular ttmors adherent to the external or internal carotid arteries render their dissection difficult and risky. we present our technique of embolization, surgical resection with follow-up of seven carotid body t~mors. We conclude that preoperative reduction of the vascularity of these tumors renders surgical resection sinloler and safer by reducing the blood supply and bulk of the tumor.

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Poster 85

Poster 86

Abstract withdrawn

PERCUTANEOUS EMBOLIZATION OF C A P I L L A R O VENOUS MALFORMATIONS D Herbreteau, R Hassani, A Casasco, F Lemarchand, MD 8rette, O Enjolras, MC Riche, JJ Msrland Dpt ol Interventional Neuroradiology, Ladboisi~re Hospital, Pads, France

Caplllaro-Venous Malformations (CVM) are mature superficial venous outpouchings that are hemodynamically inert. We have evaluated an alternative approach to extensive surgical resection, which involves shrinking the CVM by injecting a sclerosing agent. We review our 9 year experience with 200 patients treated by percutaneous embolization with Ethibloc* introduced under fluoroscopic control into different pouches, 90% wereyounger than forty, and 66% were female. Clinically, they presented with progressively enlarging subcutaneous masses. In all patients treated, we were able to achieve a good diminution in the size of the CVM, which by itself is sufficient in 75% of the patients. The remainder also underwent surgery for functionnal or cosmetic purposes only. When surgery is required, Ethibloc" avoids the risk of extensive blood loss from disseminated intra-vascutar coagulation. Recurrences due due to the natural evolution of the disease are not uncommon and usually simply require another treatment session. Minor complications wet encountered in 6% of the cases. Patients with CVM have now a new outlook. Ethibloc* is safe, effective, free of scars, may be repeated, and avoids extensive surgery.

Poster 87

Poster 88

PREOPERATIVE EMBOLISATION IN GLOMUS TEMPORALE TUMORS. 1 2 1 1 P. Piazza . L. Moschini , F. Cusmano , R. Menozzi , 2 2 1 L. Caberni , G. Belloni , P. Bassi . i) Istituto di Scienze Radiologiche, Parma (Italia).

ENDOVASCULAR TREATMENT O F SPINAL ARTERIOVENOUS MALFORMATIONS: REVIEW OF OUR 7YEAR EXPERIENCE S. A g g a r w a l , R. W i t l i n s k y , W. M o n t a n e r a , K.G. Terbrugge Dept. o f R ~ d i o l o g y , T h e T o r o n t o H o s p i t a l - W e s t e r n D i v i s i o n , 399 B a t h u r s t S t r e e t , T o r o n t o , O n t a r i o , C a n a d a M5T 2S8

2) Servizio di Neuroradiologia,

Bergamo

(Italia).

The purpose of this paper is to present our experience with embolisation(PE) in 125 patients, between 17

preoperative

and 68 years of age, affected by a glomus temporale tumor (GTE). According to the classification of Fisch-Valavanis we have preoperatively embolised 3 type A, 18 type B, 64 tZ pe C and 40 type D GTE. In the early period 45 patients underwent PE with a 4 or 5 F angiographic catheter, using pa~ ticles of lyophilized dura and a traditional angiographic equipment. The last 80 patients underwent selective transfemoral intraarterial digital subtraction angiography (DSA) and PE was performed with microparticles of PVA ranRing in size between 150-250 micron, injected through a microcatheter; 7 patients underwent also permanent ballon occlusion (PBO) of the internal carotid artery (ICA), which was extensively involved by the tumor. In all the cases a good reduction of intraoperative blood loss was achieved through PE of external carotid artery branches and PBO of the ICA allowed a safe removal of the tumor; some better results have been observed after introduction of microcathe tar and PVA. Complications related to the procedure were ob served in 4 early patients and were characterized by two ca ses of transient facial nerve paresis, one left sided hemiparesis, which was cQmpletely resolved in one month, and one episod of transient dysphasia. In conclusion we can state that PE of the external carotid artery using microcatheters PVA and DSA equipment and PBO of the ICA are safe and usefull procedures in the global management of GTE.

O v e r the past 7 years, we h a v e performed 16 endovascular therapeutic procedures on 8 patients (5 males & 3 females, a g e d 21-64 years) with spinal arteriovenous malformations (AVMs). 6 patients had d u r a l w h i l e 2 h a d i n t r a m e d u l l a r y AVMs. A t i s s u e a d h e s i v e (NBCA) w a s u t i l i s e d f o r e m b o l i s a t i o n in all p a t i e n t s . H o w e v e r , a d d i t i o n a l u s e h a d to b e m a d e o f PVA p a r t i c l e s in 3 p a t i e n t s w h e n t h e c a t h e t e r t i p p l a c e m e n t w a s u n s a t i s f a c t o r y to p e r m i t NBCA's u s e . R e s u l t s of t h e e m b o l i s a t i o n w e r e c o n s i d e r e d f a i r to e x c e l l e n t in 7 p a t i e n t s ; it w a s u n s u c c e s s f u l in one, S u r g e r y w a s n e c e s s i t a t e d in t h i s p a t i e n t , a n d a l s o in 2 others who demonstrated either less-thans a t i s f a c t o r y o c c l u s i o n of t h e n i d u s (1 p a t i e n t ) o r b e c a u s e of t h e AVM's r e c u r r e n c e a f t e r i n i t i a l g o o d o c c l u s i o n (1 p a t i e n t ) . A r e v i e w o f o u r e x p e r i e n c e will be presented,

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Poster 89

Poster 90

FLOW CONTROLLEDEMBOLISATION WITH STRONGLYDILUTED EMBOLIC MIXTURES (HISTOACRYL-LIPIODOL, ETHIBLOC-LIPIODOL) IN THE DURAL AND EXTRADURALVASCULARSUPPLY

G R A N U L O M E T R I C ANALYSIS OF SPHERICAL AND N O N - S P H E R I C A L E M B O L I Z A T I O N PARTICLES R Beaujeux, A Laurent, L Domas, M Wassef, JJ Medand

LNAT, ParisVIIUniversity,Claude-BernardResearchFund,Pads,France A. M i r o n o v Neuroradiology, KantonsspitaI, CH-5001 Aarau

Objective: Current available endovascular treatment in the dural end extradural vascular t e r r i t o r i e s are w e l l - e s t a b i lished procedures. Flow controlled embolisation using strongly d i l u t e d solutions of Histoacryl&Lipiodol or Ethibloc&Lipiodol is a technique that can be useful in a l l s i tuations where selective i n j e c t i o n cannot be achieved so f a r d i s t a l as required, but where the proximal part of the feeding vessel must be preserved. Methods: A t o t a l of 94 dural and extradural vessels in 71 patients were catheterized as s e l e c t i v e l y as possible using a Tracker-18. Then either an i n t e r m i t t e n t or a continuous i n j e c t i o n was made using a mixture of Ethibloc/Lipiodol in a r a t i o of I : I to 1:4, or of H i s t o a c r i l / L i p i o d o l in a r a t i o of I : I to 1:6. No aggravating complications of embolisation occured. Conclusion: By the use of these c a r e f u l l y prepared embolic solutions we were able to r e l i a b l y predict the s i t e of vascular occlusion (proximal versus d i s t a l ) . There is a l i near prolongation of the process of the polymerisation/ p r e c i p i t a t i o n time. Therefor, the embolisation is basical l y a controlled mechanical occlusion. The risk of occluding normal microbranches is s i g n i f i c a n t l y reduced i f not e n t i r e l y eliminated. By c a r e f u l l y planning the embolisation one can r e l i a b l y d e l i v e r a embolic solution d i s t a l l y to cause necrosis or proximally to occlude the feeders to a vascular lesion or tumor.

We have carried out the granulometric analysis of different embolization materials by the mean of two methods : optical microscopy and semi-automatical shape measurement. We have measured the size of particles according to two dimensions and determined an index adapted to the embolization particles. We have studied following particles : - non spherical : dura-mater, gelfoam, PVDF, polyvinyf alcohol - spherical : polystyrene, dextran, silicone, acrylic beads The a. m. particles have been obtained by different fabrication methods which will influence the granulometric distribution. The granulometry of the non-spherical particles (obtained by mechanical fragmentation) is wider than advertised on the commercial leaflet and frequently tends to concentrate on the minimal dimension. On the opposite the spherical particles are wetl calibrated, and especially the acrylic beads which we have been able to divide into very narrow granulometdc peaks.

Poster 91

Poster 92

PERCUTANEAOUS VERTEBROPLASTY WITH METHYL METHACRYLATE RESULTS IN 60 CONSECUTIVE PATIENTS

INTERVENTIONAL NEURORADIOLOGY IN THE SUBARACHN01D SPACE: CYST PUNCTURE AND DRAINAGE M. J. Kuhn, T. P e nc e k S o u t h e r n I l l i n o i s U n i v e r s i t y School of Medicine, Springfield, Illinois, USA

G. FOA TORRES, Y. BASCOULERGUE, F. TURJMAN, J.C LAHAROTrE, P.TOURNUT, J. DUQUESNEL HOPITAL NEUROLOGIQUE LYON Purpose : To report our clinicalexperience of percutaneous vertebroplasty. Methods: From 1985 to 1991 we performed 80 percutaneous vertebroplasty in 60 patients. Diagnosis included painful metastases of vertebral angiomas in 17 and osteoporotic vertebral crush fracture syndrome in 20. Under neuroleptanalgesia, we realised the puncture with a 18 Gauge needle (18 G-3,5), and the injection of 2-4 cc of methyl methacrylate in the vertebral body under fluoroscopic guidance. Patients underwent follow-up CT Scan 24 hours after the procedure. Results : Pain was relieved in 48 patients and a functionnal improvement was noted in 25 patients. In 3 patients the procedure was complicated by the migration of the methyl methacrylate in the spinal canal with clinical symptoms of spinal cord compression in one patient. Conclusion : This technique is safe and e f f e c t i v e in a wild variety of diagnosi~

P e rc ut a ne ous needle p u n c t u r e of i n t r a - s p i n a l and i n t r a - c r a n i a l cysts v i a a CI-C2 approach and s u b s e q u e n t p l a c e m e n t of p i g t a i l c a t he t e rs for d r a i n a g e and antibiotic administration was developed as a n e w interventional neuroradiology technique to determine its safety and efficacy. Cyst puncture is achieved by means of needle puncture into the subarachnoid space at CI-C2, Wires are then passed through the needle and pigtail catheters are passed over them into the cysts. It often becomes expedient to pass two catheters, one entering the subarachnoid space from the right and the other from the left,for the purpose of antibiotic administration to infected cysts, Cyst puncture was accomplished successfully on e l e ve n separate occasions for l o n g - t e r m d r a i n a g e and antibiotic a dmi ni s t ra t i on, No difficulty has been e n c o u n t e r e d d r a i n i n g cysts in t he c e r v i c a l s p i n a l c a na l and the p r e - p o n t i n e space. There has been no evidence of h e m o r r h a g e , n e r v e damage or infection related to t hi s procedure, even w h e n the pa t i e nt ha s left the hos pi t a l w i t h a tube in place. Long-term dra i na ge for up to 9 m o n t h s has been accomplished in a p a t i e n t w i t h bra i ns t om compression who was not a s u r g i c a l candidate. The percutaneous p l a c e m e n t of a c a t he t e r t h r o u g h a C1-C2 approach for d r a i n a g e and direct antibiotic a d m i n i s t r a t i o n of cysts appears to be safe and c l i n i c a l l y efficacious,

S 218

Poster 93

Poster 94

C.T GUIDED ASPIRATION BIOPSY OF INTRACRANIAL

THE EFFECT OF LIDOCAINE AS A PROVOCATIVE TEST DRUG: AN EXPERIMENTAL STUDY T. Terada, K. Nakai, M. Nakai, Y. Nakamura, Y. Kinoshita, T. Nishiguchi, T. Itakura, S. Hayashi, N. Komai Department of Neurological Surgery, Wakayama Medical College, Wakayama. J a p a n

LESIONS RESULTS IN 114 CONSECUTIVE PATIENTS F. TURJMAN, G. GERVESY, G. FOA TORRES, Y. BASCOULERGUE, J.C LAHAROTTE, P. TOURNUT, A. JOUVET, J. DUQUESNEL HOPITAL NEUROLOGIQUE LYON Purpose : To assess the effectiveness and safety of CT guided needle aspiration biopsy of the intracranial lesions. Methods : From 1985 to 1991 a total of 114 consecutive patients underwent biopsy with CT guidance of intracranial lesions. (G.E 9 800). The biopsy was performed with a 16 or 14 Gauge needle. A consultation between the neurosurgeon and the neuroradiologist is essential in selecting the target and the shortest and safest route through normal brain. Results : In 70 of 79 patients with suspicion of tumor, the biopsy confirmed this diagnosis (success rate 87 %) : high grade gliomas constituted the most commonlesion (29). Bacterial abcesses were diagnosed in 31 patients. Complications occured in 3 patients within a 30 days period of following (hemiparesis in one case, majoration of the deficit in 2 cases). Conclusion : CT guided biopsy is a safe and e f f e c t i v e way to obtain brain tissue specimens

for Idstopathological diagnosis.

Poster 96

Poster 95 EXPERIMENTAL INTERVENTIONAL BLOOD-BRAIN D I S R U P T I O N (BBBO) IN L E W I S RATS

BARRIER

K.Heimberger(1), N . P f a f f l m e y e r ( 2 ) , H.Lassmann(3), K.Rbssler(4) Doris. of Radiologyl, Neurology2, Neurosurgery4 and lhst', of N e u r o l o g y 3 , U n i v e r s i t y C l i n i c s , W~hringer GOrtel 18, A-I090 VIENNA, AUSTRIA S h o r t time e f f e c t s of t e m p o r a r y o s m o t i c B B B D were s t u d i e d e x p e r i m e n t a l l y in 12 a d u l t L e w i s rats. s a c r i f i c e d I and 24 hours a f t e r infusion of 2 5 % mannitol and p e r o x i d a s e tracer into the unilateral internal c a r o t i d artery. N e u r o p a t h o logically, a patchy d i s t r i b u t i o n of fracer and a u t o l o g o u s serum p r o t e i n l e a k a g e was found in the ipsilateral b r a i n h e m i s p h e r e f o l l o w i n g the

distribution of the anterior and middle cerebral arteries. W i t h i n a r e a s o f BBBO

vascular signs

of brain

edema were p r e s e n t

tier of the n e u r o p i l ,

associated

with

vacuola-

w i t h the

a p p e a r a n c e o f d a r k n e u r o n c h a n g e s . 24 h o u r s a f t e r BBBD t h e i n f i l t r a t i o n o f serum p r o t e i n s w i t h i n t h e C N S - t i s s u e was s i m i l a r to that found a £ t e r one h o u r . In a d d i t i o n , we f o u n d some neurons with eosinophilic condensed cytoplasm and n u c l e i c d i s s o l u t i o n . In c o n t r a s t t o t h e s e experimental results, N e u w e l t , C r o s s e n et a l . 1990, r e p o r t on t h e t a c k o f , n e u r o p s y c h o l o g i c a l d e f e c t s i n ( t h r o u g h one t o seven y e a r s ) m u l tiple times B B B O - t r e a t e d brain t u m o u r p a t i e n t s . In o u r p a t i e n t s w i t h 40 BBBDs, we e x p e r i e n c e d s h o r t time neurologic deficit r e l a t e d to transient edema i n 45% o f p r o c e d u r e s , and one ersistent d y s p h a s i a due t o c a t h e t e r m a n i p u l a ion. Other reversible complications were related to chemotherapy. Scrutinizin@ t h e ~g:~ d i s c r e p a n c y o f e x p e r i m e n t a l and c l i n i c a l results, t h e L e w i s Rat Model seems t o be o f l i m i ted importance for clinical valuation o f BBBD.

~

Lidocaine has been employed as a provocative test drug in endovascular surgery in spite of its incomplete informations as to the effect in the central nervous system, because amobarbital, a commonly used d r u g for provocative test, occasionally shows false negative. Present s t u d y tried to elucidate the effect of tidocaine in the r a t visual system u s i n g electrophysiology. Under urethane anesthesia, rats ( S p r a g u e - D a w l y ) were injected with various doses of lidocaine (0.0001 to 0.0025mg/kg) t h r o u g h the catheter in the left internal carotid artery. Electrophysiological activity was recorded either over the parietal cortex (ECoG) or in the lateral geniculate body (LGN). The ECoG was significantly suppressed b y the injection of lidocaine over the doses of 0 . 0 0 2 5 m g / k g . Whereas the response spikes in the LGN evoked b y the stimulation of optic chiasm were suppressed immediately by the injection of 0.0001mg/kg. These suppressions in both ECoG over the cortex and evoked responses in the LGN recovered in 15minutes under doses examined in this study. It is concluded t h a t lidocaine first affected on the neural conduction r a t h e r t h a n the neuronal activity inself even in the central nervous system a n d is useful as a provacative test d r u g in combination w i t h amobarbital.

HISTOPATHOLOGICAL STUDY OF ARTERIOVENOUS MALFORMATIONS EMBOLIZED WITH N-BUTYL 2-CYANOACRYLATE: CLINICAL AND EXPERIMENTAL ANALYSIS Y Niimi, M Tamaki, *T Terada, **K Hashimoto, **H Tabata, ***S Tsuruoka and K Nirakawa Dept. of Neurosurgery and *Pathology, Tokyo Medical and Dental University, Dept. of Neurosurgery, **Tsuchiura Kyodo Hospital and ***Toride Kyodo Hospital To evaluate the histopathological changes of brain AVMs embolized with n-butyl 2-cyanoacrylate(NBCA), authors examined seven brain AVMs excised 2-3 weeks after NBCA embolization. We also embolized 8 renal and I0 femoral arteries of rabbits and rats with NBCA and examined them 1 and 14 days later. The clinical specimens commonly showed followings: i) The proximal portion of the nidus densely packed with NBCA showed homogeneous hyalinization and thinning of the vascular wall with perivascular edema, and intramural granulation associated with infiltration of eosinophils, foreign body giant cells and small round cells. 2) The distal portion was either partially or not filled with NBCA. This portion demonstrated diffuse subintimal infiltration of polymorphonuclear leukocytes. Animal specimens 14 days after embolization showed changes i) in common, mainly in muscular arteries. However, distal arteries showed prominent granulomatous vasculitis. These changes were not observed one day after emholization. Changes I) closely resembles acute radiation induced vasculitis. This could be attributed to the heat of polymerization or the degradation products of NBCA. Changes 2) is probably secondary to marked slowness of the blood flow inside the nidus. The prominent granulomatous vasculitis in the animal specimens is similar to the findings in allergic vasculitis, which could be an etiology.

S 219

Poster 97

Poster 98

A N G I O G R A P H Y C O L O R - F L O W IMAGING O F C E R E B R A L MAV'S J.M. Pumar, M. Alvarez, J. Lade, A. Casti~eira, E. Otero, M. Li~ares. Hospital General de Galicia. Santiago de Compostela, Espafia.

COLOUH-FLOW ANGIOGRAPHY IN VALUATION OF CEREBRAL ANEURYSMS

The therapeutics used in ar teriovenous malformations treatment (MAV'S), depends on the localization and its vascular characteristics, which can be determined b y applying colour-flow techniques in the cerebral angiography. We have studied 15 patients with cerebral arteriovenous malformation by using digital cerebral panangiography. Afterwards, w e processed the images by means of pseudo-colour techniques. The pseudocolour range assigns a different colour to every single pixel of the image~ at any moment of the sequence, depending on contrast maximum concentration. I n 8 of t h e 15 c a s e s , t h e c o l o u r - f l o w t e c h n i q u e s gives us additional information (compared to c o n v e n t i o n a l a n g i o g r a p h y ) . I t allows u s to d e m o n s t r a t e more precisely the arterial contribution, flow a n d venous d r a i n a j e s a s well a s t h e e x i s t e n c e o r n o e x i s t e n c e of a n g i o m a t o u s c h a n g e s . We t h i n k c o l o u r - f l o w cerebral angiography can be v e r y useful in t h e planning and checking of the therapeutics in arteriovenous malformations.

J.M. Pumar, M. Alvarez, P. Rivas, .4. Pardo, J. VIDAL, J.

Feijoo. Hospital General Espafia.

de

Galicia.

Santiago

de

Compostela.

The new interventional neurovascular techniques for aneurysms treatment (by using detachable balloons, coils} have a very important handicap. It's the calculation of embolization material to fill the aneurysms, attending to the existence or no-existence of thrombus. B y means of the application of the colourflow technique in the cerebral angiography, w e try to demonstrate the thrombus existence, as well as the existence of free lumen and the circulation in the aneurysm. This will allow us to calculate the amount of embolization material w e have to use. W e have studied 20 patients with cerebral aneurysm by using digital cerebral panangiography. W e carried out series in different projections. Afterwards, w e processed the image by using pseudo-colour techniques. The pseudo-colour range assigns a d i f f e r e n t c o l o u r to e v e r y s i n g l e pixel of t h e i m a g e , a t a n y m o m e n t of t h e s e q u e n c e , d e p e n d i n g of c o n t r a s t maximum c o n c e n t r a t i o n . T h e o b t e n t i o n of c o l o u r - f l o w i m a g e s in c e r e b r a l a n g i o g r a p h y h a s a l l o w e d u s to c h e c k t h e e x i s t e n c e of a n e u r y s m s w i t h t h r o m b u s in 12 c a s e s , a s well a s to d e t e r m i n e t h e c h a r a c t e r i s t i c s of t h e c i r c u l a t i o n i n t h e a n e u r y s m s . We t h i n k t h i s t e c h n i q u e c a n be v e r y u s e f u l in p r e - t h e r a p e u t i e v a l u a t i o n of c e r e b r a l a n e u r y s m s .

Poster 100

Poster 99 PROBL]~ OF I N T E R I A L F I B R I N O L Y S I S

PRE-THERAPEUTIC

IN ACUTE CAROTID

OCCLUSION - PATUOLOGICALEVALUATION

OF TIlROMBOI~IBOLIC OCCLUSION N Kuwayama, S Endo, R lwai, and A Takaku Department of Neurosurgery, Toyama Medical & Pharmaceutical University Some p r o b l e m s a r e o f f e r e d a b o u t t h e i n t r a a r t e r i a l fibrinolysis in acute c a r o t i d o c c l u s i o n from the pathological findings of resected atherosclerotic p l a q u e s d e r i v e d from p a t i e n t s with severe carotid stenosis or o c c l u s i o n . Carotid endarterectomy was performed in t h i r t y p a t i e n t s with s e v e r e s t e n o s i s or acute o c c l u s i o n of the o r i g i n of i n t e r n a l carotid artery. P a t h o l o g i c a l f i n d i n g s o f r e s e c t e d p l a q u e s were c l a s s i f i e d i n t o t h r e e t y p e s ; 1. a l a r g e a t h e r o s c l e r o t i c plaque with or without u l c e r a t i o n in cases with s e v e r e stenosls, 2. p l a q u e h e m o r r h a g e c o n n e c t e d w i t h c l o t occupying the intravaseular lumen in cases with p s e u d o o c c l u s i o n , 3. p l a q u e and b l o o d c l o t o c c u p y i n g t h e whole intravascular lumen in cases with acute oceulusion. Local intraarteria! fibrinolysis was performed in four patients with acute carotid occlusion in i t s origin. R e c a n a l i z a t i o n was n o t a c h i e v e d in t h r e e and o c c l u s i o n o f m i d d l e c e r e b r a l a r t e r y was c o m p l i c a t e d i n one. In conclusion, the pathological examination a c c o u n t e d f o r t h e d i f f i c u l t y i n c l o t - l y s i s and d a n g e r s f embolism t o d i s t a l b r a n c h e s . Some c o n s i d e r a t i o n is needed to r e s o l v e these problems.

THE VALUEOF NEUROPYSIOLOGICALMONITORING IN INTERVENTIONAL PROCEDURE Y gonishi, M Hara and 1 S a i t o Department of Neurosurgery, kyorin University School of Medicine, Tokyo, Japan The p e r i o p e r a t i v e observation of neurological changes is of great importance for softy i n t e r v e n t i o n a l procedures. In t h i s regard, we have devised a neurophysiological monitoring system composed of brainstem auditory evoked p o t e n t i a l s (BAEP). somatosensory evoked p o t e n t i a l (SEP). transcranual Doppler sonography (TCD) and EEG-CSA. This system was used in angiop l a s t y for vasospasm (8 cases), treatment of aneurysm (ANM- 14 c a s e s ) , e m b o l i z a t i o n of arteriovenous malformation (AVM- 6 cases), and i n t r a a r t e r i a l chemotherapy for brain tumors (BT- 13 eases). In occlusion t e s t of the i n t e r n a l c a r o t i d a r t e r y (ICA) in ANM cases, theflow r a t e in the middle cerebral a r t e r y (MCA) was f i r s t measured by TCD, and followed by s i n g l e photon emmission CT for c e r e b r a l blood flow shudy. The occlusion t e s t was again performed with the detachable balloons i t s e l f monitoring by EEGCSA, and t h e r e a f t e r the balloon ~as detached. In d e t e c t i o n of vasospasm, TCD ~as continuously monitored everyday a f t e r e l i p p i n g of aneurysm, and angioplasty ~as indicated in cases shewing v e l o c i t y e f the MCA g r e a t e r than lOO c s / s e c on TED and c a r r i e d out to obtain slum v e t o c i t y under lOO c a / s e e on TCD. in cases of AVM, s i c r o c a t h e t e r mas i n s e r t e d into the feeding a r e t r i e s and Amytal t e s t was performed under SEP and EEG-CSA monitoring. Rmbelization was c a r r i e d out if the testwas negative, in case of i n t r a - a r t e r i a I chemotherapy for BT, TCD monitoring e a s i l y detected narrowing of the iCA causes by mechanical vasospasm due to the c a t h e t e r . Monitoring mas possible in a l l cases. Our neurophysiological monitoringis easy and useful for s a f e l y procedures and i t s value and n e c e s s i t y ~ i l l be emphasized in t h i s report.

S 220

Poster 101

Poster 102

DEVELOPMENT OF THE CATHETER FOR ANGIOPLASTY AND OCCLUSION OF CAROTID ARTERIES

ENDOVASCULAR TREATMENT OF SUBCLAVIAN ARTERIO-VENOUS FISTULAS D Herbreteau, A Aymard, M Khayata, D Reizine, MC Riche, JM Cormier, JJ Merland Dpt of lnterven|ionalNeuroradiology,Lariboisi~reHospital,Paris,France

Atsushi Inugami, Toshihide Ogawa, Fumio Shishido, Hideaki Fujita, Eku Shimosegawa, Hiroshi Ito, Matsutaro Murakami, Iwao Kanno, Kazuo Uemura, Department of Radiology and Nuclear Medicine, Research Institute for Brain and Blood Vessels-Akita, Akita, JAPAN Development of a specially designed angioplasty ant temporary occlusion balloon catheter for the carotid arteries. The catheter will 1) not scatter micro embori or thrombi in the distal area accompany with angioplasty, 2) enable to washout the micro embori or thrombi, 3) enable to perfuse the intracranial area, and 4) enable to direct using guide wire. < D e s i g n > Four lumens and 7 or 6F diameter are necessary to satisfy the above conditions. The catheter has end hole, temporary occlusion balloon (polyurethane), side hole for washout, plasty balloon (a kind of polyester) and polyurethane shaft. A 0.028 inch guide wire, enable to use. We tried angioplasty and balloon Matas test using this specially designed catheter, and confirmed usefulness of the catheter.

We evaluated patients undergoing endovascular treatment of subclavian arteriovenous fistulas. Since 1984 we have treated six patients with subclavian arterio-venous fistulas (AVF). They were all of iatrogenic origin (5 venous punctures and one pacemaker insertion) Clinically there were two patients with cardiac insufficiency, three with bruit, and one with upper extremity venous hypertension. Angiographically, four were located on the thyrocervicat trunk and two on the internal mammary artery. All were treated by endovascular occlusion with a detachable balloon with full resolution of their symptoms. One recurrence secondary to premature balloon deflation required retreatment with subsequent cure. There were no complications of treatment, Endovascular balloon occlusion of subclavian AVFs is a simple, effective, and safe method which eliminates the need for surgery. This should be the method of choice for these lesions.

Poster 103

Poster 104

SYNTHESIS, EXPERIMENTAL STUDIES, AND CLINICAL ASSESSMENT OF BIOCOMPATIBLE NEW EMBOLIZATION MICROSPHERES A Laurent1, R Beaujeux 1, M Wassef 1, JJ Merland1, E Boschetti 2, M Brouard2, G Leconte2 tLNAT, ParisVllUnivers~r/,Claude-BernardResearchFund,Pads,France 2 IBF,Villeneuvela Garenne,France

BIODEGRADABLE STARCH t~ICROSPHEFIES FOR CAROTID EMBOLIZATION: A NEW AN!MAL MODEL FOR ANALYSIS OF BRAIN DAMAGE O Lacoourreye, A Laurent, M Potivka,G Pigr~aud,JJ Mertand LNAT Paris Vl{ Unive.'slty,Ctau~e-BemardReset.febFur>~,Hopttal LafibolSi~te, Paris,France

The material improvements of a new type of acrylic microspheres were : 1) adaptation of the synthesis techniques to obtain a complete range of diameters; 2) adaptation of the microsphere surface as to boost the cellular adhesion ; 3) division into different calibers to obtain very narrow peaks of granulometry (+ 50, _+ 100 It) ; 4) polymer coloration. Animal biocompatibility evaluation has been evaluated on Sprague Dowley rats. Host response, endothelial react!on were not unusual, compared with other materials. These microspheres have been tested on 89 patients : 19 tumors, 11 facial AVM, 34 spinal cord AVM, 19 cerebral AVM, 6 miscellaneous. For all of them the embolization was feasable and easy without any aggregation problem either in the catheters or in the vascular network. No complication occured, related to the particles. For 22 patients (from the previous group) we compared the efficiency of two types of microspheres (narrow peak distribution (-+ 50 p.) and wide peak distribution (+ 300 p.)) according to angiographic devascularisation, surgical benefit and histological consequences. Microspheres of the first group allowed the targetting of the embotization, on the opposite, microspheres of the second group allowed only a proximal embolization without necrosis (p < .05, Chi 2). These microspheres present many advantages and ~ltow accurate targetting of the embolization.

Various materials are utilized ".o peffornl intra-cerebrat and cervical emboiization in case of head and neck :Minors and malformations. This preliminary p,'ospective study was designed to analyse if biodegradabie sta:ch microspheres cou!d be safe!y utilized in such cases. A new e,rteria! emboliza!ion procedure, with respect of the intem~l carotid artery, is described in order ',o a!!ow for cerebral embolization in an awakened animal Twenty awakened Sprague Dawiey r~.ts rec$ivec; various amounts of biodegradable starch microsphe~es a; the level of the brain. They were sacrificed at various d~!ays, an~.t histopatbo~ogicatstudy cf brains was pe~om'~e~. Analysis of of results suo~lests that such microspheres behave as non degradab!e micmsphores in tl'e brain.

S 221

Poster 106

Poster 105 REQUIREMENTS FOR THE USE OF ETHIBLOC~m IN INTERVENTIONAL N E U R O R A D I O L O G Y

F. Brassel, H. B e c k e t Neuroradiologie~ Medizinische Hannover, Germany

Hochschule

E t h i b l o c ~ is a h i g h l y v i s c o u s e m h o l i c m a t e rial c o n t a i n i n g corn protein (Zein) a n d contrast media in a 38.3 Vol.% ethanol solution. F o r m o r e t h a n 10 y e a r s it h a s b e e n s u c c e s s f u l l y u s e d to o c c l u d e renal arteries and pancreatic d u c t s . H o w e v e r , t h e h i g h v i s c o s i t y of E t h i b l o c R itself precludes its use in microcatheters with interventional neuroradiology. Ethibloc ~ must therefore b e m i x e d in a s o l u t i o n w i t h 3 0 5 0 % of an o i l - b a s e d c o n t r a s t m a t e r i a l . Optimal s u s p e n s i o n is a c h i e v e d by r e p e a t e d a l t e r n a t i n g injections between two syringes connected by a Polyamid 3-way stopcock. The product should then appear homogenous and have a milky to creamy consistancy. To prevent rapid fractionation into Ethib l o c R a n d oil layers, h e a t i n g of t h e s u s p e n s i o n should be avoided and it m u s t be u s e d i m m e d i ately. A s standard luer lock adapters become b r i t t l e in contact with the Ethibloc R suspension, t h e y must be replaced with pediatric Polyamid Touhy Borst Adapters. In o r d e r t o p r e vent premature p r e c i p i t a t i o n of the Ethibloc R s u s p e n s i o n in t h e m i c r o c a t h e t e r , it i s i n j e c t e d using the sandwich technique with a 20% glucose solution. Multiple embolizations using the same catheter are then possible. We studied the characteristics of t h e E t h i bloc R embolization via microcatheters in vitro, in a v - m a l ~ o r m a t i o n s a n d in t u m o r s . W e a l s o d e m o n s t r a t e d p e r m a n e n t o c c l u s i o n of v a s c u l a r t e r ritories.

H/:EMOCOMPATIBILITY OF ARTERIAL CATHETERS EVALUATION ON HUMAN ARTERIAL BLOOD IN ANGIOGRAPHIC CONDITIONS AL Bailly1, A Laurent 1, J Dufaux 2, R EIoy3, JP Lamoureux1, JJ Merland1 1LNAT,PadsVUUniversity,Claude-BernardResearchFund,Pads,France 2LBHPCNRS343, PafisVl[University,Pads,France 31NSERMU37.Lyon-Bron,France To evaluate the thrombogenicity of angiographic catheters we developed two in vivo human arterial blood models. Six different types of 5F catheters: 2 polyethylene (PE), 2 polyamid (PA), 1 polyurethan (PU), and 1 polytetrafluoroethylene (PTFE), and two different types of 3F catheters: 1 with hyd'rophilic coating and 1 PE, were tested in angiographic conditions. Immediately after femoral artery puncture, the test catheter was introduced and a standardized flow rate was obtained. Blood flow rate was measured up to 10 minutes or until catheter thrombosis occured. Three tests were done for each material. Among the 5F catheters, three significantly (p<0.0001) different groups were found- group A : PEn ° 2 - group B : PU, PAn ° 2, PEN ° 1, and PTFE - group C : PA n°l. Group A showed no thrombosis at 10 min, group B showed thrombosis between 7 and 10 min, and group C showed thrombosis before 5 min. The two 3F catheters thrombosed in t0 mn, with no significant difference. For all catheters, no correlation was found between thrombogenicity and the base material. The thrombogenicity seems to result from a combination of base material, technological additives, specific additives (antioxidants, plastifiers, colorants, radioopacifiers and chemical stabilizers), method of extrusion and final sterilization process.

Poster 107

Poster 108

NONINVASIVE A S S E S S M E N T OF A CAROTID-SUBCLAVIAN STEAL SYNDROME TREATED BY PTA

NONINVASIVE HEMODYNAMIC MONITORING DURING NEURORADIOLOGICAL INTERVENTIONS BY TRANSCRANIAL DOPPLER SONOGRAPHY F. Ries, L. Solymosl* Departments of Neurology and *Neuroradlology University of Bonn. FRG

F. Pales,L. Solymosi*, J. Klar Departments of Neurology and *Neuroradiology University of Bonn, F R G Subclavian steal syndrome generally is characterized by a vertebro-vertebral collateral flow. Diagnosis a n d asscssmcnt of h e m o d y n a m l c changes is done reliably by noninvasivc cxtraa n d transcranial Doppler sonography. Clinical s y m p t o m s normafiy arc mild, leading to only rare indications for surgical intervention.

A 67y. old female patient presented with lefthemispheric s y m p t o m s including sensomotor TIA, mixed a p h a s i a a n d mental confusion. Extracranial Doppler sonography demonstrated a hlgh-grade proximal subclavian stenosis, combined to a hypoplastic right vertebral artery. Conventional handheld TCD exam as well as 3-D "trans-scan" mapping (EME/FRG) surprisingly showed a carotid-basflar collateral supply, mainly fed by the left posterior communicating artery. This steal m e c h a n i s m led to substantial as well as hemodynamic lesions in the MCA territory, as s h o w n by CT scan, MRI and Xenon-CT. Considering recurrent neurological deficits, indication for a surgical intervention w a s given. Transluminal angioplasty of the subclavian stenosis w a s done during a continuous monito~ng of the ipsflateral vertebral artery respectively the basflar artery by m e a n s of handheld TCD. Immediatly following the angioplasty, flow direction in the basflar artery changed to a to-andfro pattern, in presence of a n evidently patent proximal subclavlan artery, as s h o w n by angiography. On day 1, increased flow velocities in the left vertebral artery a s well as in the basflar artery were found in Doppler examinations. The basflar artery n o w w a s showing a n antegrade flow direction. During follow-up for more t h a n one year, the flow direction stayed antegrade in the basllar 'artery, while neurological s y m p t o m s nearly disappeared.

Transcranial Doppler sonography (TCD) As a highly reliably tool in a s s e s s i n g hemodynamic p a r a m e t e r s of the b a s a l cerebral arteries. Complementary to initial diagnosis by extra- a n d transcranial Doppler devices, we u s e d TCD monitoring with a continuous registration of absolute blood flow velocities during embolizations of AVMs as well as in I~A. AVMs includes 7 AV angiomata, 4 giant a n c u r y s m s , 6 carotid-cavernous fistula. A preintervenflonal Doppler exam w a s followed by intrainterventional monitoring, t h u s allowing an immediate a s s e s s m e n t of hemodynamic, eventually critical changes in the vascular territory to be touched by embolization. Iatrogenic ICA occlusion in case of giant a n e u r y s m s were detected immediatly, including the development of collateral pathways. In CCS-fistula, progressive hemodynamic changes were followed for several m o n t h s . Patients collective undergoing angioplastic procedures mainly include subclavian steal syndrome (n=15), combined angioplasty and endarterectomy in a traumatic ICA dissection (n=l} and drug-induced lysis in basflar thrombosis (n=5). According to the vascular territory, monitoring w a s done in the ipsflateral vertebral artery, the basllar artery or the lpsflateral MCA. All patients were followed u p directly postinterventionally a s well as after several m o n t h s . Main advantages of TCD monitoring include an immediate a s s e s s m e n t of hemodynamlc insufficiencies of blood s u p p l y in angioplastic procedures, detection of latrogenic vascular obstructions in embolization, noninvasive follow-up with description of new collateral pathways after embollzation as well a s early detection of reoceluslon, dissection or t h r o m b o s i s after angioplasty.

S 222

Poster 110

Poster 109 MRI APPEARANCEOF CERVICAL DISKS FOLLOWING CHEMONUCLEOLYSIS : A PROSPECTIVESTUDY J.L. DRAPE; D. KRAUSE; D, N'GUYEN~ P. LEGUENNEC; D. MAITROT; J. TONGIO UNIVERSITY HOSPITALSTRASBOURG - HAUTEPIERRE

Purpose : The MR1 follow-up of cervical chemonucleolysis for cervicobrachial neuralgia treatment.

disks following resisting medical

~aterials and methods : systematic MRI study of the cervical spine in 15 patients with disk herniations at C5 - C6 (6) or C6 - C7 (9), before and after chemonueleolysis (follow-up interval ranged from 6 weeks to 3 months). Sequences used : TI, T2. Gadolinium with sagittal sections. This f i r s t series of 15 patients was compared with another group of 15 patients with a longer MRI follow-up period (2 - 3 years after therapy), Results : This prospective s~u~y investigated : the morphology and signal of the treated disk. as well as the corresponding vertebral endplates and spinal cord segment. Conclusion : Despite the contraindications given by the pharmaceutical firm Boots-Dacour, cervical chemonucleolysis has proven its efficacy (authors' experience : 200 patients over 4 years). The aim of this prospective study is to demonstrate the innocvousness of the method with respect to the treated disk (which remains in place), and to neighboring structures, particularly the spinal cord.

ASSESSMI~NT OF T~{E EXPE~I~CE WITH BASILAR ARTerY THROMBOLYSIS WITHIN THE WFITN R. C. Dawson Department of Radiology, Vanderbilt University, Nashville, USA One of the goals of the World Federation of Therapeu~tic and Interventional Neuroradiology must be the establishment of a central data bank for diseases and therapies in which the individual ex6~rience is disparate and episodic. We destributed a questionnaire regarding the treatment of basilar artery thrcmbosis to WFITN members to assess the efficacy of this form of data aquisition as well as to evaluate the various protocols thus far attempted to treat this rare but usually devastating disease. Of 103 members, in 20 countries, surveyed 60 percent of 76 patients. Experience with basilar artery thrombolysis is restricted as only 8.7 percent of WFTIN members report having attempted this somewhat revolutionary therapy. Nonetheless successful outcomes, described as improvea~nt since presentation or mild to moderate residual neurological deficit, have been achieved in over 50 percent of patients. The various protocols, including dosage, time tables, and methods of administration of treated thrc~f0olytic agent and hep~rin are s ~ r i l y reported.

Membership List American Society of Head and Neck Radiology Abrahams, James J. M.D. (AM) Department of Diagnostic Radiology Yale University School of Medicine 333 Cedar Street (Office) New Haven, CT 06510 (203)785-5102

Awwad, Eric E., M.D. (AM) Radiology University Hospital 1325 S Grand (Office) St Louis, MO 63104 (314)577-8025:

Adapon, Benjamin D., M.D. (Ofelia) (AS) Makati Medical Center 2Amorsolo Street (Office) Makati Metro Manila, Philippines

Babbel, Robert Welker, M.D. (AM) Department of Radilogy University of Utah Medical Center 50 North Medical Drive (Office) Salt Lake City, UT 84132 (801)581-2414

Ahn, Hyo S., M.D. (Soon Ho) (AM) Department of Radiology John Hopkins Hospital 3 Norwick Circle (Home) Timonium, MD 21093 (301)955-2789: Akiya, Frederick I., M.D. (AM) 1009 Quincy, NE (Home) Albuquerque, NM 87110 (505)262-0728 Alenghat, Joseph, M.D. (Liz) (AM) Department of Radiology Mercy Hospital & Medical Center Stevenson Expressway (Office) at King Drive Chicago, IL 60616 (312) 567-2433: Andrews, Jerry, M.D. (Cecilia) (AM) Kettering Memorial Hospital 3535 Southern Blvd (Office) Kettering, OH 45429 (513)296-7227: Aravapalli, Sambasiva Rao, M.D. (AM) Dept of Radiology SUNY Health Science Center 4865 Westfield Drive (Home) Manlius, NY 13104 (315)464-7437: Ascherl Jr., George E, M.D. (Susan Emily) (AM) Department of Radiology Bay Medical Ctr t900 Columbus Ave (Office) Bay City, MI 48708 (517)894-3080: Augustyn, Gary Thomas, M.D. (AM) Dept of Radiology Catherine McAuley Health Center P.O. Box 992 (Office) Ann Arbor, MI 48106 (313)572-230t:

Badami II, John P., M.D. (Maria) (AM) Department of Radiology Sequoia Hospital District Whipple and Alameda (Office) Redwood City, CA 94062 (415)367-5536: Baker, Richard A., M.D. (Ann) (AM) Lahey Clinic Foundation 41 Mall Rd (Office) Box 541 Burlington, MA 01803 (617)244-4042: Ball Jr., James B., M.D. (Carol) (AM) Florida Hospital 208 Wildcreek Ct (Home) Longwood, FL 32779 (407)897-1944: Ball, Marshall, M.D. (Laura) (AM) Dept of Radiology Bowman Gray School of Medicine 300 S Hawthorne Rd (Office) Winston-Salem, NC 27103 (919)748-4435: Bankoff, Mark, M.D. (Ann) (AM) Department of Radiology New England Medical Center 750 Washington St (Office) PO BOX 180 Boston, MA 02111 (617)956-0043:

Bell, Kenneth, M.D. (Anne) (AM) Ochsner Ctinic Radiology 1514 Jefferson Hwy (Office) New Orleans, LA 70121 (504) 838-3489: Benitez-Lopez, Wanda I., M.D. (AM) University of Arkansas for Med. Sciences 7 Allison Court (Home) Searcy, AR 72143 (501)686-6032: Benson, Manfred T., M.D. (AM) William Beaumont Hospital 3601 West Thirteen Mile Road (Office) Royal Oak, MI 48072 (313)551-6068 Bergeron, R. Thomas, M.D. (Dottie) (AM) Dept of Radiology Long Island College Hospital 340 Henry St (Office) Brooklyn, NY 11201 (718)780-1793: BeviUe, Lee Walker, M.D. (AM) Holloman AFB NM 8 33rd Med Group (Office) 1281 Municipal #0 Alamogordo, NM 88310 Bhimani, Sultan M., M.D. (AM) Department of Radiology Hurley Medical Center One Hurley Plaza (Office) Flint, MI 48503 (313)258-9210 Bilaniuk, Larissa T., M.D. (Oleksa-Myron) (AM) Dept of Radiology Hospital University of Penn 3400 Spruce St G t (Office) Philadelphia, PA 19104 Bisker, Jeffrey S., M.D. (AM) 33 Boundbrook Ct. (Home) E. Amherst, NY 14051 (716)636-1679

Becker, Terry, M.D. (AM) USC Suite 103 (Office) 48 N E1 Molino Ave Pasadena, CA 91101 (818)795-4381:

Btackwell, Randall D., M.D. (Shirin) (AM) The Methodist Hospital 52 Crestwood Circle (Home) Sugafland, TX 77478 (713)790-2001:

Belkin, Rod, M.D. (AM) Radiology L340 Vancouver Radiologists P.S. 3305 Main St #201 (Office) Vancouver, WA 98663 (206)694-2565:

Blas, Lou, M.D. (AM) Radiology Dept St Joseph's Ragional Medical Ctr Box 816 (Office) Lewiston, ID 83501 (209)799-5335:

S 224 Bloch, Solomon, M.D. (Joyce) (AM) Spring Branch Memorial Hospital 422 E Gaywood (Home) Houston, TX 77079 (713)467-6555: Bloom, David, M.D. (Phyllis) (AM) Medical Diagnostic Inc 591 Chestnut Hill Ave (Home) Brookline, MA 02146 (617)270-9560: Bolender, Nicole F., M.D. (AM) 8616 NE 23rd P1. (Office) Bellevue, WA 98004 Bonstelle, Charles, M.D. (Sandy) (AM) Good Samaritan Med Ctr I 111 E McDowetl Rd (Office) Phoenix, AZ 85062-2989 (602)239-4600: Braun, Ira E, M.D. (Lyn) (AM) Dept of Radiology Baptist Hospital of Miami 8900 Norht Kendall Drive (Office) Miami, FL 33176-2197 (305)596-1960:6696

Byrd, Sharon E., M.D. (AM) Children's Memorial Hospital 5510 N Sheridan Rd (Home) Apt 12A Chicago, IL 60640 (312)880-3565:

Citrin, Charles, M.D. (Donna) (AM) The Neurology Ctr Suite #1765 (Office) 5454 Wisconsin Ave NW Chevy Chase, MD 20815 (301)652-3410:

CaiUe, Jean-Marie, M.D. (Suzanne) (AS) Serv de Neuroradiology PellegrinTripode Pace Amelie Raba Leon (Office) Poste 4603 Bordeaux Cedex, 33076 France

Coin, Gene, M.D. (Lib) (AM) Institute of Diagnostic Services P.O. Box 698 (Home) Long Key, FL 33001 (407)655-6677:

Cala, Lesley, M.D. (AS) Sir Charles Gairdner Hospital P.O. Box 105 (Home) Cottesloe, WA 6011 Australia (09)389-3333:18 Carter, Barbara, M.D. (Jeff) (AM) Dept of Radiology New EngIand Med Ctr 750 Washington St (Office) #438 Boston, MA 02111 (617)956-0050:

Breger, Robert K, M.D. (AM) Dept of Radiology Univ of Wisconsin Clinical Science Ctr 3220 Applegate Ct (Home) Brookfield, WI 53005 (608)263-9179:

Chakeres, Donald W., M.D. (Linda)(AM) Dept of Radiology OSU Hospitals $209 Rhodes Hall (Office) 410 W 10th Ave Columbus, OH 43210 (614)293-8315:

Breit, Robert A., M.D. (AM) 1631 Charleston Ct. (Home) Melrose Park, IL 60160 708/681-2290

Chandra-Sekar, B., M.D. (AM) 1721 Cedarwood Road (Home) Birmingham, AL 35216 205/823-6537

Brogan, Martha Anne, M.D. (AM) The Ohio State University 5033 Glenaire Drive (Home) Dublin, OH 43017 (614)293-8181:

Chikos Jr., Paul, M.D. (Katharine) (AM) Valley Medical Center 24723 142nd Ave. SE (Home) Kent, WA 98042 (206)251-5183:

Brown, Frank A., M.D. (Susan) (AM) 754 Santa Rita Way (Home) Sacramento, CA 95864 (916)444-0645:

Chin, Munn Wey, M.D. (Edean) (AM) Department of Radiology Palomar Memorial Hospital 550 E Grand Ave (Office) Escondido, CA 92025 (619)739-3350:

Brugman, Joseph J, M.D. (AM) 1100 N. Tustin Ave (Office) Santa Ana, CA 92705 (714)835-6055: Bryan, R. Nick, M.D. (Jean) (AM) Dept. of Radiology Johns Hopkins Hospital Meyer 8-140 (Office) 600 N. Wolfe Street Baltimore, MD 21205 Burke, Robert David, M.D. (AM) 11 Sheldrake Lane (Home) Palm Beach Gardens, FL 33418 (407)626-2787

Chisin, Roland, M.D. (AS) 14/4 HabanaiStreet (Home) Bet. Hakerem Jerusalem, Israel Chuang, SylvesterH, M.D. (AM) Hospital for Sick Children 555 University Ave (Office) Toronto, ON M5G1X8 Canada (416)598-6080: Cintron, Elsie, M.D. (AM) 125 Alheli St (Home) Urb San Francisco San Juan, PR 00927

Coit, William E., M.D. (Holly) (AM) P.O. Box 10768 (Office) Portland, OR 97210 (503)229-7127: Cook, Albert, M.D. (AM) Children's Medical Center 3541 Stimson Road (Home) Norton, OH 44203 (216)666-8318: Crawford, Stephen C, M.D. (AM) 1920 Huntington Rd (Office) Birmingham, AL 35209 (205)871-1756: Cromwell, Laurence, M.D. (Debby) (AM) Dept of Radiology Dartmouth Hitchcock Med Ctr 2 Maynard St (Office) Hanover, NH 03756 (603)646-8315: Curtin, Hugh, M,D. (Carole) (AM) Radiology Eye and Ear Hosp 230 Lothrop St (Office) Pittsburgh, PA 15213 (412)647-2196: Curtis, David, M.D. (Ebie) (AM) Dept of Radiology SB 05 George Washington Univ Med Ctr 901 23 St NW (Office) Washington, DC 20037 (301)320-2633: D'Amonr, Peter G., M.D. (AM) 200 Hawthorne Lane (Office) Charlotte, NC 28204 Dalley, Robert W. (AM) Dept. of Radiology Harborview Medical Center 6816 48th Avenue, N.E. (Office) Seattle, WA 98115 (206)223-3561: Damsma, Henk, M.D. (M) (AS) Dept of Radiodiagnosis Stichting StreekziekenhuisHilversum Loosdrechtse Bos 7 (Office) Hilversnm, 1213 RH The Netherlands (30)372-161 :

S 225 Daniels, David, M.D. (Amy) (AM) Dept of Radiology Froedtert Memorial Lutheran Hosp 9200 W Wisconsin Ave (Office) Milwaukee, WI 53226 (414)259-3122:

Dillon, William P., M.D. (AM) Dept of Radiology L371 Univ of CA San Francisco 505 Parnassus Ave (Office) San Francisco, CA 94143 (415)739-9379:

Danziger, Allan, M.D. (Renee) (AS) Lawrence Hospital 55 Palmer Rd (Office) Bronxville,NY 10708 (914) 337-7300:

Dolan, Kenneth, M.D. (Arlene) (AM) Dept of Radiology University of Iowa Hospitals Iowa City, IA 52242 (319)356-3381:

Emery, Christine D., M.D. (AM) Dept of Radiology Pennsylvania Hospital 8th and Spruce Streets (Office) Philadelphia, PA 19107 (215)829-3201:

Dastur, Khurshed J., M.D. (Meher) (AM) Dept of Radiology Mercy Hospital Price and Locust Sts (Office) Pittsburgh, PA 15219 (412)232-7374:

Dolinskas, Carol Anne, M.D. (AM) 7312 Emlen St (Home) Philadelphia, PA 19119 (215)829-3201:

Farrell Jr., Frank Wilson, M.D. (AM) 3155 Maplewood Avenue (Home) Wiston-Salem, NC 27103 (919)760-5878:

Donner, Martin W., M.D. (Heidi) (AM) Dept of Hospital Johns Hopkins Hospital Baltimore, MD 21205 (301)955-7697:

Fierstien, Stephen B., M.D. (AM) 1335 Berea Place (Home) Pacific Palisades, CA 90272 (213)273-3337:

Davidson, Kendrick C., M.D. (Barbara) (AM) 4320 Wornall Rd Suite 710 (Office) Medical Plaza Building Kansas City, MO 64111 (816)531-9481: Davis, David O., M.D. (Agnes) (AM) Dept of Radiology George Washington Med Ctr 901 23rd St NW (Office) Washington, DC 20037 (206)994-4653: Davis, Kenneth, M.D. (Jill) (AM) Dept of Neuroradiology Mass General Hosp Fruit St (Office) Boston, MA 02114 (617)726-8329: Dawson, Robert C., M.D. (AM) 408 Ashlawn Ct. (Home) Nashville, TN 37215 (615)322-0999 Deeb, Ziad L., M.D. (AM) Allegheny General Hospital Department of Diagnostic Radiology 320 East North Avenue (Office) Pittsburgh, PA 15212 412/359-4122 De Vries, Nicholas, M.D. (AM) Department of Radiology Mercy Hospital & Medical Center Sixth & University (Office) Des Moines, IA 50314 (515)247-4338: Delbalso, Angelo, M.D. (Carol) (AM) 30 Boundbrook Ct (Home) East Amherst, NY 14051 (716)898-3416: Desai, Praful C., M.D. (Sue) (AM) Midland Hospital Center 4005 Orchard Dr (Office) Midland, MI 48640 (517)839-3443:

Dorwart, Robert, M.D. (Nancy) (AM) Crouse Irving Memorial Hosp 736 Irving Ave (Office) Syracuse, NY 13210 Dreisbach, James, M.D. (Susan) (AM) 1328 E Layton Ave (Home) Englewood, CO 80110 (303)788-6080: Dublin, Arthur, M.D. (Kathryn Grant) (AM) Diagnostic Radiological Imaging Med Group 79 Scipps Dr #100 (Office) Sacramento, CA 95825 (916)921-1300: Dubois, Philip, MBBS (AS) Radiology Mater Priv Hospital Raymond Terrace (Office) S. Brisbane So Brisbane QLD, 4101 Australia Duchesneau, Paul M., M.D. (Ronnie) (SM) Cleveland Clinic Foundation 9500 Euclid Ave (Office) Cleveland, OH 44106 (216)444-6646: Duda, Eugene E., M.D. (Susan) (AM) Department of Radiology Christ HospitalMed Ctr 4440 W 95th St (Office) Oak Lawn, IL 60453 (312)857-5520: Easterbrook, James, M.D. (Pat) (AM) 601 E Rochelle (Home) Irving, TX 75062 (214)944-8264: Edwards, Jon, M.D. (AM) Radiology St Lukes Rossevelt Hospital 428 W 59th St (Office) New York, NY 10019 (212)523-7076:

Eisenman, Jack, M.D. (Clara) (AM) Martin Luther King Jr Gen Hosp 12021 S Wilmington Ave (Office) Los Angeles, CA 90059 (213)603-4701:

Fisk, John, M.D. (AM) P.O. Box 370 (Office) Bellevue, WA 98009 Free, Thomas W., D.O. (AM) 3620 Spencer Blvd. (Home) Sious Falls, SD 57103-4613 605/339-4394 Friedland, James T. M.D. (AM) 393 Peregrine Drive (Home) Indialantic, FL 32903 407/773-9329 Friedman, David Paul, M.D. (AM) 6100 City Avenue, Apt. 1513 (Home) Philadelphia, PA 19131 215/473-1697 Fruin, Mark Edward, M.D. (AM) Department of Radiology University Hospital 50 North Medical Drive (Office) Salt Lake City, UT 84132 801/581-7553 Gabrielsen, Trygve O., M.D. (Ragnhild) (AM) Radiology B 1 D53OF Univ of Michigan Hosp 1500 E Medical Center Dr (Office) Ann Arbor, MI 48109 (313)936-4467: Gargano, Fredie, M.D. (Evie) (SM) Palmetto General Hospital 2001 W 68th St (Office) Hialeah, FL 33010 (305)823-5000: Garvin, Charles E, M.D. (AM) Department of Radiology St. Lukes Hospital 232 S. Woods Mill Road (Office) Chesterfield, MO 63017 314/851-6894

S 226 Gatenby, Robert, M.D. (Abby) (AM) Dept of CT Scanning American Oncologic Hospital Central and Shellmire Ave (Office) Philadelphia, PA 19111 (215)728-2971: Gentry, Lindell, M.D. (Sue) (AM) Univ. of Wisconsin Hospitai & Clinics 5491 Maves Rd (Home) Madison, WI 53711 (608)263-9513: Gerson, Lester, M.D. (AM) 6621 Fannin (Office) Houston, TX 77030 Gibbs, S. Julian, M.D. (AM) Dept of Radiology and Rad Sci Vanderbilt Univ Med Ctr Nashville, TN 37232 Gilbert, George, M.D. (AM) Greater SE Community Hospital 1310 Southern Ave SE (Office) Washington, DC 20032

Hanafee, William, M.D. (Connie) (AM) Department of Radiology UCLA Medical Center Los Angeles, CA 90024 (213)825-8473:

Hemmati, Masoud, M.D. (AM) Michael Reese Hospital & Medical Center 2409 Meadow Drive North (Home) Wilmette, IL 60091 (312)791-4567:

Handel, Stanley, M.D. (Carolyn) (AM) 5419 Valerie (Home) Bellaire, TX 77401 (713)778-9800:

Hendrickson, Glenn C., D.O. (AM) Olympia Fields Osteopathic Medical Ctr. 15401 S Orland Brook (Home) Orland Park, IL 60462 (312)747-4000:1180

Hardin, Carl Wayne, M.D. (AM) South Texas Radiology Group P.O. Box 691148 (Home) San Antonio, TX 78269 (512)692-0202: Hardman, Donald R., M.D. (AM) Radiotogic Specialists of Indiana Inc 8711 Green Braes South Drive (Home) Indianapolis, IN 46234 (317)929-3443: Harnsberger, Ric, M.D. (Janet) (AM) Department of Radiology University of Utah Medical Ctr. 50 North Medical Drive Salt Lake City, UT 84132 (801)581-7553

Gilmor, Richard L., M.D. (Sharon) (AM) Dept of Radioiogy Methodist Hospital of Indiana 1701 N Senote Blvd (Office) Indianapolis, IN 46202 (317)929-8568:

Harper, Paul, M.D. (Debbie) (AM) 4008 Winterberry PI (Home) Charlotte, NC 28210

Goldstein, Edwin, M.D. (Fran) (AM) Radiology and Imaging Associates 550 West Thomas Rd (Office) Phoenix, AZ 85013 (602)274-3661:

Harris Jr, John, M.D. (Cathy) (AM) Univ of Texas Med School 6431 Fannin St 2.132 (Office) Houston, TX 77030 (713)792-5235:

Goldstein, Steven, M.D. (Susan) (AM) 1916 Lakes Edge Drive (Home) Lexington, KY 40502 (502)636-7474:

Harwood-Nash, Derek, M.D. (Barbara) (AM) Department of Radiology Hospital for Sick Children 555 University Ave (Office) Toronto, ON M5G 1X8 Canada (416)598-6025:

Guerrero E., Ilka M., M.D. (AM) Frontera #75 (Office) Colonia Roma, 06700 Mexico D.E (533)633-5 : Guinto, Faustino, M.D. (Virginia) (AM) Radiology University of Texas Med Galveston, TX 77550 (409)761-2230: Guirardo, Carmen R., M.D. (AS) Muntaner 239 Enlo A (Office) Barcelona, 08021 Spain (320)032-00 : Haas, David K., M.D. (Marian C.) (AM) Chief Neuroradiology and MR 3012 W. Oakley (Home) Las Vegas, NV 89102 Han, Soo Sung, M.D. (AM) Dept of Radiology Pennsylvania Hospital 8th and Spruce Street (Office) Philadelphia, PA 19107 (215)829-3201:

Hasso, Anton N., M.D. (Peggy) (AM) Department of Radiology Loma Linda University 11234 Anderson (Office) Loma Linda, CA 92354 (714)824-4394: Hatten Jr., tL Paul, M.D. (Dell) (AM) Radiology Assoc of Birmingham 1020 Huntington Road (Home) Birmingham, AL 35209 (205)871-1754: Hayes, Elizabeth, M.D. (AM) Univ of Massachusetts Med Ctr 8121 Paisley Place (Home) Potomac, MD 20854 (508)856-2215: Hecht-Leavitt, Charles, M.D. (AM) MRI Diagnostics 4668 Pembroke Blvd. (Office) Virginia Beach, VA 23455 804/671- 1144

Hinshaw Jr., David, M.D. (Marcia) (AM) MRI Section Loma Linda University 11234 Anderson (Office) Loma Linda, CA 92354 (714)824-4013: Hirsch Jr., William L., M.D. (AM) Department of Radiology Prebyterian University Hospital DeSoto at O'Hara Streets (Office) Pittsburgh, PA 15217 (412)647-3530: Ho, Peter S. P., M.D. (Hsing-Ping) (AS) Department of Radiology Tri Service General Hospital 622 Ting Chow Road (Office) Taipei, 10713 Taiwan, R.O.C. Hockett, Sheri L., M.D. (David) (AM) Memorial Hospital of Garland 3143 Carth Blvd. (Home) Dallas, TX 75225 (214)487-5172: Hoffman Jr., James C., M.D. (Judy) (AM) Department of Radiology Emory University Clinic 1365 Clifton Rd NE (Office) Atlanta, GA 30322 (404)727-4583: Holl Jr., Carl W, M.D. (Donna) (AM) Community Hospital of Indianapolis 408 Trilbey Ct (Home) Noblesville, IN 46060 (317)353-5814: Holliday, Roy, M.D. (AM) Radiology NY Univ Med Ctr 550 First Ave (Office) New York, NY 10016 (212)340-5215: Holmes, Stephen M., M.D. (Melissa) (AM) Radiology Associates Inc 1250 Lauhala St (Office) Suite 103 Honolulu, HI 96813 (808)547-4711: Horowitz, Barry, M.D. (Diana) (AM) Department of Radiology The Methodist Hospital 6565 Fannin (Office) Houston, TX 77030 (713)790-2001:

S 227 Horowitz, Sandra W., M.D. (AM) Radiology Department Loyola University Medical Center 2160 S. 1st Avenue (Office) Maywood, IL 60153 708/216-5221 Houser, Otis W., M.D. (AM) Mayo Clinic 200 First Streets SW (Office) Rochester, MN 55905 (507) 284-8550: Huckman, Michael S., M.D. (AM) Department of Diagnostic Radiology and Nuclear Medicine 1653 West Congress Parkway (Office) Chicago, IL 60612 312/942-5781 Hudgins, Patricia A., M.D. (AM) Radiology/Neuroradiology Emory University School of Medicine 1365 Clifton Road, N.E. (Office) Atlanta, GA 30322 (404)727-4583: Hutchins, Lawrence Guy, PhD, MD (AM) Marshfield Clinic 1000 N. Oak Avenue (Office) Marshfield, WI 54449 715/387-5262 Jabour, Bradley A., M.D. (AM) 10966 Strathmore Drive, No. 7 (Home) Los Angeles, CA 90024 213/206-4481 Jackson, Donald Earl, Jr., M.D. (AM) 3560 N Street (Home) Eureka, CA 95501 707/445-5993 Jacobs, Louis, M.D. (AM) Radiology Assoc of Atlanta/Piedmont Hosp 12 Ivy Chase NE (Home) Atlanta, GA 30342 (404) 350-3583: Jacobs, Morton, M.D. (Sandi) (AM) 121 E 60th St (Office) New York, NY 10021 (212)838-4243: James, Reese Joseph, D.O. (AM) 1508 Woodlea Drive (Home) Leesburg, VA 22075 (301)856-3670: Janecka, Ivo P., M.D. (Cheryl) (AS) Dept. of Otolaryngology University of Pittsburgh (Office) Eye and Ear Institute 203 Loghrop St Suite 500 Pittsburgh, PA 15213 (412)647-2110:

Jhaveri, Harish S., M.D. (AM) Division of Nueroradiology Department of Radiology The University of TX Southwestern Medical Center 5323 Harry Hines Boulevard (Office) Dallas, TX 75235-8896 214/688-3904 Johnson Jr., Daniel H., M.D. (Susan) (AM) Clearview Medical Imaging 3100 Clearview Parkway (Office) Metairie, LA 70006-5304 (504) 885-4223: Johnson, Dexter, M.D. (Pam) AM) Swedish Hosp Med Ct 747 Summit Ave (Office) Seattle, WA 98104 (206)292-6233: Johnson, Michele H., M.D. (AM) 8327 Flourtown Avenue (Home) Wyndmoor, PA 19118 Kantor, Mel L., D.D.S (AS) Oral Diagnosis/Radiology L6062 Univ of Connecticut Health Ctr 201 Main Street (Home) #B4 Farmington, CT 06032 (203)679-2773: Kassel, Edward, M.D. (AM) Department of Radiology Sunnybrook Medical Center 2075 Bayview Ave (Office) Toronto, ON M4N 3M5 Canada (416) 480-4369: Kaufman, Benjamin, M.D. (Barbara) (SM) Department of Radiology University Hospital of Cleveland 2065 Abington Rd (Office) Cleveland, OH 44106 (216)844-3116: Kell, Thornton, M.D. (Donna) (AM) Cardinal Cushing General Hospital 1107 Webster St (Home) Needham, MA 02192 (617) 588-4000: Kelly, John Kevin, D.O. (AM) Dept Diagnostic Radiology Neuro Section Harper Hospital 3990 John R. Street (Office) Detroit, MI 48201 313/745-8411 Kessler, Howard B., M.D. (Hope) (AM) Department of Radiology Jeanes Hospital 7600 Central Avenue (Office) Philadelphia, PA 19111 (215)728-3041:

Khan, Arfa, M.D. (Faroque) (AM) Radiology Long Island Jewish Medical Center New Hyde Park, NY 11042 (718) 470-7170: Khandji, Alexander G., M.D. (AM) Columbia Presbyterian Medical Ctr 1-Cindy Lane (Home) Irvington, NY 10533 (212) 305-3051: Kido, Daniel, M.D. (AM) Univ of Rochester Med Ctr P.O. Box 694 (Office) 601 Elmwood Rochester, NY 14642 Kienzle, Gregory D., M.D. (AM) 6 New Berm (Home) Madison, WI 53719 (608) 263-9179: Kim, Byung, M.D. (AM) Racine Radiologist 3803 Spring St (Office) Racine, WI 53405 (414) 632-5580: King, David E., M.D. (AM) Radiology Department The Methodist Hospital 6565 Fannin M.S. D 281. (Office) Houston, TX 77030 (713) 790-2001: Kirkwood, John, M.D. (Gale) (AM) Baystate Medical Center 759 Chester St (Office) Springfield, MA 01107 (413) 784-4661: Knopf, David R., M.D. (AM) 9 Medical Arts Center (Office) Savannah, GA 31405 912/355-3642 Kumar, Ashok A.J., M.D. (AM) Department of Radiology Johns Hopkins Hospital Division of Neuroradiology (Office) 600 N. Wolfe Street Baltimore, MD 21205 Kurman, Andrew J., M.D. (AM) 451 Lake of the Woods Blvd. (Home) Akron, OH 44333-2791 216/864-6213 Laine, Fred J., M.D. (AM) Radiology Department Medical College of Virginia Box 615, MCV Station (Office) Richmond, VA 23298-0615 (804)786-1900: Lamontagne, Lucie B., M.D. (AM) Dept Radiologie, Faculte de Med Universite de Sherbrooke 3001 Nord 12e Avenue (Office) Fleurimont, PQ JIH5N4 Canada (819) 653-5555:

S 228 Lane, Barton, M.D. (Elizabeth) (AM) Neuroradiology Stanford University School of Medicine Diagnostic Radiology, H-1307 (Office) Standford, CA 94305 (415)725-4922:

Lee, K. Francis, M.D. (AM) Dept of Radiology Univ of Miami, School of Medicine JMH, WW2, R-109 (Office) P O Box 016960 Miami, FL 33101

Lanzieri, Charles K, M.D. (Shirley) (AM) Director of Neuroradiology University Hospital Case Wester Reserve Univ (Office) 2074 Abington Rd Cleveland, OH 44106 (216)844-5721:

Lee, S. Howard, M.D. (Taeja Kim) (AM) Department of Radiology Muhlenberg Hospital Park Ave and Randolph (Office) Plainfield, NJ 07061 (201)668-2180:

Larkin, Brian T., M.D. (AM) 2441 Byrnes Road (Home) Minnetonka, MN 55343 612/546-5375 Larson, David, M.D. (Kathy) (AM) Dept of Radiology Metropolita - Mt. Sinai 900 S 8th St (Office) Minneapolis, MN 55404 (612)347-4213: Larson III, Theodore Carl, M.D. (AM) Nashville Memorial Hospital 5333 Granny White Pike (Home) Brentwood, TN 37027-4111 (615)860-1526: Larsson, Sven G., M.D. (Anita) (AS) Avd. F. Diagn. Radiologi Akademiska Sjukhuset Uppsala, S-75185 Sweden (461)866-4732:

Lee, Nam Joon, M.D., Ph.D. (AS) Department of Radiology HaeWha Hospital Korea University Medical Center 4, 2-ka, Myungyun-Dong, Chongro-Ku (Office) Seoul, 110-522, KOREA 02-762-51t 1 ext.575 Leo, Jin Shone, M.D. (AM) Radiology Department Texas Tech Univ Health Sciences Lnbbock, TX 79430 (806)743-2688: Levine, Richard, M.D, (Jill) (AM) Department of Radiology St Johns Mercy Hospital 615 S New Bolkas Rd (Office) Creve Coeur, MO 63141 (314)569-6865: Lidov, Mika W., M.D. (AM) 370 Riverside Drive, 7E (Home) New York, NY 10028 212/222-1625

Lufkin, Robert B., M.D. (AM) Assoc of Professor of Radiology Dept of Radiology UCLA Medical Center Los Angeles, CA 90024 Lupetin, Anthony, M.D. (Metissa) (AM) Radiology Allegheny General Hospital 320 E North St (Office) Pittsburgh, PA 15212 (412)359-4897: Mafee, Mahmood, M.D. (Mahvash) (AM) Department of Radiology Univ of Illinois Hospital 840 S Wood St (Office) Chicago, IL 60612 (312)996-9200: Mancuso, Anthony, M.D. (AM) Department of Radiology Shands Teaching Hospital Box J374 JHMHC (Office) Gainesville, FL 32610 (904)395-0106: Manke, William, M.D. (Betty) (AM) Diagnostic Radiology Presbyterian Med Ctr 1719 E 19th Ave (Office) Denver, CO 80218 (303)839-6520: Marano, Gary, M.D. (AM) 2 Poplar Woods (Home) Morgantown, WV 26505

Liebeskind, Doreen, M.D. (AM) 10 Shorecliff Place (Home) Great Neck, NY 11023

Mark, Alexander S., M.D. (AM) Dept of Radiology Washington Hospital Center 3416 Portec St NW (Home) Washington, DC 20016 (202)877-3139:

Latchaw, Richard E., M.D. (AM) Dept of Radiology Swedish Medical Center 501 E Hampden (Office) Englewood, CO 80110 (303)788-6080:

Lin, Zwu Shin, M.D. (Seh-Seh Lin) (AM) Department of Radiology 689 Lehigh Vy Hosp Ctr 1200 S Cedar Crest Blvd (Office) Allentown, PA 18105 (215)776-8088:

Martin, David Stuart, M.D. (AM) Department of Radiology St. Louis University Hospital 3635 Vista at Grand (Office) St. Louis, MO 63110-0250 314/577-8025

LaValley, Antoinette L., M.D. (AM) 2920 Tracewood Drive (Home) Toledo, OH 43615 419/843-4487

Littteton III, Jesse T., M.D. (Martha) (SM) Department of Radiology Univ of S. Alabama Coll of Med 2451 Fillingrim St (Office) Mobile, AL 36617 (205)471-7674:

Martinez, Carlos R., M.D. (Maria-Carolina) (AM) Radiology Assoc of Tampa 6C Columbia Dr (Office) Tampa, FL 33606 (813)253-2721:

Lo, William, M.D. (Rhoda) (AM) St Vincent Med Ctr 2131 W 3rd St (Office) Los Angeles, CA 90057 (213)484-7901:

Mawad, Michel E., M.D. (AM) The Methodis Hospital 6565 Fannin, MS 033 (Office) Houston, TX 77030 713/790-4826

Loes, Daniel J., M.D. (AM) Dept of Radiology Univ of Iowa Hospitals & Clinics GH $717 (Office) Iowa City, IA 52242 (319)356-3385:

Merlis, Anthony, M.D. (AM) 7111 Applewood Dr (Home) Madison, WI 53711

Laster, D. Wayne, M.D. (AM) Department of Radiology Bowman Gray School of Medicine 234 Ohio St (Home) Corpus-Christie, TX 78404

Leake, David, M.D. (Marsha) (AM) Radiology Consultants 222 Bartlett St (Home) # 205 Austin, TX 79912 (512)480-1750: Lee, Benjamin, M.D. (AM) Dept of Radiology Univ of Minnesota P.O. Box 292 (Office) 420 Delaware St SE Minneapolis, MN 55455 (612)626-6635:

S 229 Messina, Albert, M.D. (AM) 17 Ridge Dr E (Home) Great Neck, NY 11021 (212)628-0665: Michotey, Pierre, M.D. (AS) Le Chaumont I 122 Rue du c Rolland (Home) Marseille, 13008 France (912)294-36 : Miller, Gary M., M.D. (AM) Dept of Radiology Mayo Clinic Rochester, MN 55905 (507)284-8550: Miller, Jack David, M.D. (Miriam) (AM) Department of Radiology Univ of Alberta Hosp 8440 112th St (Office) Edmonton, AB T6G 2B7 Canada (403)492-4880: Miller Jr, Kenneth D., M.D. (Anita) (AM) Dept of Radiology Ochsner Clinic 1514 Jefferson Hwy (Office) New Orleans, LA 70121 (504)838-3483: Miller, Ronald J., M.D. (AM) Radiology Nuclear Medicine Inc 21918 Hillandale Rd (Home) Elkhorn, NE 68022 (402)559-2777: Millet, David, M.D. (Carol) (AM) IDE Radiology Group 75 Stuyvesant Rd (Home) Pittsford, NY 14534 (716)244-1130: Mirich, David R. (AM) 73 Harlandale Ave (Home) Willowdale, ON M2N 1N9 Canada (416)369-5525: Momose, K. Jack, M.D. (SM) Dept of Radiology Mass Eye & Ear Infirmary 243 Charles St (Office) Boston, MA 02114 (617)726-8392: Monajati, Ahmad, M.D. (AM) Rochester General Hospital 1425 Portland Ave (Office) Rochester, NY 14621 /716)338-3580: Montana, Margaret A., M.D. (AM) 1820 Gilpin (Office) Suite 210 Denver, CO 80218 (303) 388-6396: MueUer, Donald P., M.D. (Pamela) (AM) Dept of Radiology Univ of Iowa Hosp & Clinics Iowa City, IA 73120

Nadalo, Leonard, M.D. (AM) 7261 Tangleglen Dr (Home) Dallas, TX 75248 Nadel, Lyn, M.D. (AM) 7260 SW 109th Terrace (Home) Miami, FL 33156 Naidich, Thomas P., M.D. (AM) Baptist Hospital of Miami 8900 N Kendall Dr (Office) Miami, FL 33176 (305)596-6595: Nixon, John Randall, M.D. (AM) 2126 Edenton Road (Home) Charlotte, NC 28211 704/364-4060

Peck, Wallace W., M.D. (Patricia) (AM) Department of Radiology St Joseph Hospital 1100 W Stewart dr (Office) Orange, CA 92668 (714)771-8171: Peters, Keith R., M.D. (AM) Department of Radiology University of Florida Box J-374, JHMHC (Office) Gainesville, FL 32610-0374 904/395-0104 Petro, George R., M.D. (AM) Wilson Memorial Hospital 7776 Braniff Circle (Home) Clay, NY 13041 (607)763-6104:

Noyek, Arnold M., M.D. (Judy) (AS) Otolaryngology Mt. Sinai Hospital 600 University Ave (Office) Suite 401 Toronto, ON M5G 1X5 Canada (416)586-5142:

Poirier, Virginia C., M.D. (AM) Dept of Radiology UCD School of Medicine 2516 Stockton Blvd (Office) Sacramento, CA 95817 (916)453-3608:

Nugent, Robert A., M.D. (Bob) (AM) University of B.C. 10880 Athabasca Drive (Home) Richmond, BC V7A 4Z4 Canada (604)875-4366:

Pollei, Steven Ray, M.D. (AM) Center for Diagnostic Imaging 5775 Wayzata Blvd., Suite 190 (Office) St. Louis Park, MN 55416 612/541-1840

Osborn, Anne, M.D. (Ronald) (AM) University of Utah 50 N Medical Dr (Office) Salt Lake City, UT 84132 (801)581-7553:

Ponder, Timothy H., M.D. (Laurie) (AM) 3008 Rosedale Avenue (Home) Dallas, TX 75205 (214)946-4397:

Palacios, Enrique, M.D. (Renee) (AM) Chairman Department of Radiology MacNeal Hospital 3249 S Oak Park Ave (Office) Berwyn, IL 60402 (312)795-3357:

Potter, Guy D., M.D. (Pearl) (AM) Professor of Radiology Coll of Physicians & Surgeons Columbia University 176 East 77th Street (Home) New York, NY 10021 (212)526-7044:

Paprocki, Thaddeus R., M.D. (Catherine) (AM) 1560 N. ll5th Street (Office) Suite G 1 Seattle, WA 98133 (206)365-4100:

Pressman, Barry, M.D. (AM) Dept of Radiology Cedars Sinai Med Ctr C/O Tower Radiology (Office) 8631 W 3rd St Los Angeles, CA 90048 (213)855-3705:

Paquet, Donald J., M.D. (AM) Associated Radiologists Ltd 450 West Fifth Place (Office) Mesa, AZ 85201 (602)969-3537:

Pripstein, Stephen, M.D. (Rochelle) (AM) Abington Memorial Hospital 226 Callohill Road (Home) Chalfont, PA 18914 (215)441-8770:

Parker, Geoffrey Dean, BMBS, FRACR(AS) 31 Woodfield Avenue (Home) Fullarton 5063 SA Australia 61 (8) 2717155

Quint, Douglas J., M.D. (AM) 1020 Spruce Drive (Home) Ann Arbor, MI 48104 (313)936-4469:

Patel, Dushyant, M.D. (Kathy) (AM) Department of Radiology Michael Reese Hospital 29th St and Ellis Ave (Office) Chicago, IL 60616 (312)791-4567:

Radecki, Paul D., M.D. (AM) Department of Diagnostic Imaging Temple University Hospital Broad & Ontario (Office) Philadelphia, PA 19140 215/221-3612

S 230 Rail, M. Reza, M.D. (Gissou) (AM) Department of Radiology Mercy-Hospital Pride and Locust Sts (Office) Pittsburgh, PA 15219 (412)232-7523: Rao, Krishma, M.D. (Kusuma) (AM) Prince Georges Hospital Hospital Dr (Office) Cheverly, MD 20785 (301)341-2282: Rao, Vijay, M.D. (A. Koneti) (AM) Thomas Jefferson Hosp 111 S llth St (Office) Philadelphia, PA 19107 (215)928-4804: Raofl, Bahram, M.D. (AM) Diagnostic Radiology Dept Univ of Illinois Hosp 8219 Kathryn Ct (Home) Burr Ridge, IL 60521 (312)996-0234: Reede, Deborah, M.D. (AM) 235 Adams Street (Home) Brooklyn, NY 11201 Remty, Kent B., M.D. (AM) 595I Scenic Place (Home) Shoreview, MN 55126 612/490-7639 Rich, Philip, M.D. (Barbara) (AM) Imaging Assoc Oakland Providence Hospital P.O. Box 23030 (Office) Oakland, CA 94623 (415)874-8094: Rider, Robert, M.D. (AM) Rad Med Grp of Santa Cruz County 1661 Soquel Dr (Office) Santa Cruz, CA 95065 (408)476-7711: Rippe, David Joel, M.D. (AM) Duke University Medical Center 208 Afton Square (Home) Apt 207 Altamonte Springs, FL 32714 (9t9)681-2711: Rodriguez, Justo, M.D. (AM) Cook County Hospital 703 Thatcher (Home) River Forest, IL 60305 (312)633-8792: Rosas, Heraldo B., M.D. (AM) Eye and Ear Infirmary Univ of Illinois 303 Desplaines Av (Home) Apt 507 Forest Park, IL 60130 (312)996-9200:

Rosen, Lawrence, M.D. (Ruth) (AM) St Francis Medical Center 3630 Imperial Highway (Office) Lynwood, CA 90262 (213)603-6022:

Sane, Paul, M.D. (Malca) (AM) NY Medical College t8 Woodland Terrace (Home) Orangeburg, NY 10962 (914)285-8550:

Rosenbaum, Arthur E., M.D. (Rona) (AM) 4400 Syracuse Road (Home) Cazenovia, NY 13035

Sato, Yutaka, M.D. (AM) Department of Radiology University of Iowa Hospitals & Clinics (Office) Iowa City, IA 52242 319/356-1955

Rosenbloom, Scott, M.D. (Cindy) (AM) Division of Radiology Cleveland Clinic Foundation 9500 Euclid Ave (Office) Cleveland, OH 44106 (216)444-6643: Rosenbloom, Shelley, M.D. (AM) DX Neuroradiology 5465 Blair Rd Ste 100 (Office) Dallas, TX 75231 (214)373-8300: Rothman, Stephen L. (AM) Rothman Chafetz Medical Group Inc. 3605 Long Beach Blvd. #209 (Office) Long Beach, CA 90807 (213)539-5951: Ruprecht, Axel, D.D.S. (AM) University of Iowa Dental Science Bldg. 5356 (Office) Iowa City, IA 52242-0101 Russell, Eric J., M.D. (Sandy) (AM) Dept of Radiology NW Memorial Hospital Olson Pavilion (Office) 710 Fairbanky Ct Chicago, IL 60611 (312)908-2462: Sacher, Michael, M.D. (Patti Lou) (AM) Radiology Mt Sinai Medical Center One Gustave Levy Place (Office) New York, NY 10029 (212)241-4015: Sackett, Joseph R, M.D. (AM) Dept of Radiology E3/366 Clinical Science Center 600 Highland Ave (Office) Madison, WI 53792

Scales, Richard L., M.D. (AM) 5133 Plantation Drive (Home) Indianapolis, IN 46250 317/578-8901 Schatz, Charles, M.D. (AM) Tower Head & Neck Imaging 444 S. San Vicente #106 (Office) Los Angeles, CA 90048 (213)655-7111: Schellhas, Kurt, M.D. (Jane) (AM) Center for Diagnostic Imaging 575 Wayzata Blvd (Office) Suite 190 St Louis Park, MN 55416 (612)541-1840: Schepp, Robert Scott, M.D. (AM) Medical Director MRI-CT Scanning, Inc. 197 Third Avenue (Office) New York, NY 10003 212/982-1132 Schimel, Sandra, M.D. (AM) 1301 E McDowell Rd (Office) Suite 104 Phoenix, AZ 85006 (602)239-4600: Schmidt, Rodney P., M.D. (Pamela) (AM) Austin Radiological Assoc 4212 Med Pkwy Box 4099 (Office) Austin, TX 78765 (512)458-9291: Schwartz, Alan Neil, M.D. (AM) Veterans Hosp/Univ of Washington 14008 Riviera P1 NE (Home) Seattle, WA 98125 (206)764-2409:

Saint Louis, Leslie, M.D. (AM) Kips Bay Diagnostic 87-46 Chelsea St (Home) Apt 7 B Jamaica Estates, NY 11432 (212)213-5100:

Seibert, Charles, M.D. (AM) Radiology Imaging Assoc 3576 S Logan St (Office) Englewood, CO 80110 (303)761-9190:

Sandlin, Marlin E., M.D. (Jo) (AM) Dept of Radiology 207 Methodist Hospital 6565 Fannin (Office) Houston, TX 77030 (713)790-2001:

Seidenwurm, David J., M.D. (Page Robbins) (aM) UCSF 1690 Lexington (Home) San Mateo, CA 94402 (415)221-4810:X381

S 23] Shaffer, Katherine, M.D. (Bill) (AM) Department of Radiology Milwaukee County Medical Complex 8700 W Wisconsin Ave (Office) Milwaukee, WI 53226 (414)257-5200: Shah, Chunilal, M.D. (Kanta) (AM) Department of Radiology Univ of So F1 Box 17 12901 N 30th St (Office) Tampa, FL 33612 (813)974-2538: Shapiro, Robert, M.D. (Pearl) (AM) Univ. of Miami, Medical School 4400 Sanders St (Home) Hollywood, FL 33021 (305)549-6894: Siemers, Paul T., M.D. (Beverly)(AM) Baylor University Rad 3500 Gaston Ave. (Office) Dallas, TX 75246 (214)820-3219: Smirniotopoulos, James G., M.D. (Fran) (AM) Asst Chairman & Chief, Neuro Dept. of Radiologic Pathology Armed Forces Institute of Pathology Washington, DC 20306-6000 (202) 576-2889: Smith, Julius, M.D. (EM) Memorial Sloan Kettering 1275 York Ave (Office) New York, NY 10021 Smith, Richard Russell, M.D. (AM) Department of Radiology University Hospital X-64 926 W. Michigan St. (Office) Indianapolis, IN 46202-5253 317/274-1840 Smoker, Wendy, M.D. (AM) Department of Radiology Medical College of Virginia Box 615, MCV Station Richmond, VA 23298 Solti Bohman, Livia G., M.D. (AM) Radiology St Vincent Medical Center 2131 W 3rd St (Office) Los Angeles, CA 90057 (213)484-7908: Som, Peter, M.D. (Judy) (AM) Radiology Mt Sinai Hosital One Gustave Levy Place (Office) New York, NY 10029 (212)241-7420: Song, In Sook Yu, M.D. (Chul Sup) (AM) Bronx VAMC Church St P.O. Box 710 (Home) Alpine, NJ 07620 (212)579-1636:

Spickler, Eric Marshall, M.D. (AM) 6931 Knollwood Circle (Home) W. Bloomfield, MI 48322 313/932-1107 Stamatakos, Michael, M.D. (Dot) (AM) Radiology Sacred Heart Hospital 4th and Chew St (Office) Allentown, PA 18102 (215)439-0868: Stayton, Chester, M.D. (Frances) (EM) 3418 Bay Road South Drive (Office) Indianapolis, IN 46240 (317)787-3296: Stears, John C., M.D. (AM) Department of Radiology Univ of Colorado Health Sciences Cntr Box AO34 (Office) 4200 E Ninth Ave Denver, CO 80262 (303)270-8874:

Tadmor, Rina, M.D. (AS) Division of Neuroradiology Sheba Medical Center Tel Hashomer, 52621 Israel (035)341-0345:395 Talbot, John, M.D. (Frieda) (AM) Department Diag Radiology Oregon Health Sci Univ 3181 SW Sam Jackson Pk Rd (Office) Portland, OR 97221 (503)279-7576: Tamakawa, Yoshiharu, M.D. (Etsuko) (AS) Radiologist Iwate Medical Univ 1-I9 Uchimaru Morioka (Office) Ctr. Radiological Science Iwate, 020 Japan (019)651-5111: Tanenbaum, Lawrence Neil, M.D. (AM) 11 Devon Road (Home) Edison, NJ 08820 201/603-9340

Stecker, Michael, M.D. (AM) Cigna Hospital 2955 Motor Ave (Home) Los Angeles, CA 90064 (213)484-3070:

Tatelman, Maurice, M.D. (Fern) (SM) 7525 Gainey Ranch Rd. #150 (Home) Scottsdale, AZ 85258-1607

Stevens, Edwin, M.D. (11) (AM) 7777 Forest Lane (Office) Suite B-420 Dallas, TX 75230 (214)661-7041:

Thompson, Joseph R., M.D. (AM) Department of Rad Sci A353 Loma Linda Univ Med Ctr 11234 Anderson (Office) Loma Linda, CA 92354 (714)824-4395:

Sung, Ki Joon, M.D. (AS) Wonju College of Medicine Wonju Christian Hospital Yonsei University (Office) 162 Ilsan-Dong Wonju, 220-701 Korea (037) 142-3131:

Tien, Robert D., M.D. (AM) Dept of Radiology UCSD Medical Center 225 Dickenson St (Office) San Diego, CA 92103 (619)543-3856:

Suss, Richard A., M.D. (Shelley)(AM) 5938 Desco Dr (Home) Dallas, TX 75225-1603 (214)641-1633:

Tisdal, Rebecca Goen, M.D. (AM) Radiologic Specialties, Ltd. 4045 NW 64th, Ste 125 (Office) Oklahoma City, OK 73116 405/848-0075

Swartz, Joel, M.D. (Nancy) (AM) Medical College of Pennsylvania 1615 RiverviewRd (Home) Gladwyne, PA 19035 (215)842-6337: Syokora, Glenn, M.D. (Mary Lou) (AM) Deaconess Medical Arts Bldg 4255 Pearl Rd (Office) Cleveland, OH 44109 (216)661-0161: Sze, Gordon, M.D. (AM) 1150 Park Avenue (Home) New York, NY 10128 Tabor, Ellen K. (AM) Department of Radiology Eye and Ear Hospital 230 Lothrop Street (Office) Pittsburgh, PA 15213 (412)647-2168:

Torbey, Peter, M.D. (Pamela) (AM) Radiology Christ Hospital 4440 W 95th St (Office) Oak Lawn, IL 60453 (312)857-5520: Truski, Patrick, M.D. (Deb) (AM) Radiology Univ of Wisconsin 600 Highland Ave (Office) Madison, WI 53705 (608)263-8308: Tsai, Fong, M.D. (Jean) (AM) Radiology Truman Med Ctr 2301 Holmes St (Office) Kansas City, MO 64108 (816)556-3273:

S 232 Tze, Ka-Khy, M.D. (AM) L-60maga Drive (Office) Newark, DE 19713 (302)738-9300: Unger, June M., M.D. (George) (AM) Department of Radiology Univ of Wisconsin Clinical Science Center (Office) 600 Highland Ave Madison, WI 53792 (608)263-8349: Urso, May J., M.D. (AM) Department of Radiology (HB-6) Cleveland Clinic 9500 Euclid Avenue (Office) Cleveland, OH 44109 216/444-4516 Valvassori, Gatdino, M.D. (Eleanor) (AM) 697 Sheridan Road (Home) Winnetka, IL 60093 (312)788-9400: Vignaud, Jacqueline, M.D. (AS) Fond A De Rothschild 25 Rue Manin (Office) Paris, 75019 France (331)480-3654:8 Vincent, Miriam E., M.D. (Mim) (AM) Radiology Service 114 VA Medical Center 150 S Huntington Ave (Office) Boston, MA 02130 (617)739-3435: Vogl, Thomas, M.D. (Claudia) (AS) Department of Radiology University of Munich Munich 70, 8000 West Germany (089)709-5275:0

Weber, Alfred, M.D. (Gloria) (AM) Mass Eye and Ear Infirmary 243 Charles St (Office) Boston, MA 02114 (6t7) 573-3563:

Yeakley, Joel, M.D. (AM) Univ Tx Health Sci Center 6431 Fannin 2130 MS MB (Office) Houston, TX 77030 (713)797-2813:

Weissman, Jane L., M.D. (AM) Eye and Ear Hospital 230 Lothrop Street (Office) Pittsburgh, PA 15213 412/647-2t68

Yousem, David M., M.D. (AM) Department of Radiology-Neuroradiology Section Hospital of the University of PA 3400 Spruce Street (Office) Philadelphia, PA 19104 215/662-6865

Westesson, Per-Lennart, DDS, PhD (EM) 34 Copperwoods (Home) Pittsford, NY 14534 716/383-0287 Whelan, Margaret, M.D. (AM) Holy Name Hospital 333 Henry Hudson Pkwy (Home) Riverdale, Apt. 15M Bronx, NY 10463 (201)833-3312: Wilbrand, Hermann, M.D. (Marlen) (AS) Radiologist Department Diagnostic Rad Uppsala University Hospital 85 Uppsala (Office) Uppsala, S 751 Sweden (018)664-771 : Williams, Daniel W., III, M.D. (AM) Department of Radiology CB #7510, School of Medicine (Office) The Univ of North Carolina at Chapel Hill Chapel Hill, NC 27599-7510 919/966-3084 Wiot, Jerome Geoffrey, M.D. (AM) University of Cincinnati/Unv. Hospital 9882 Timbers Drive (Home) Cincinnati, OH 45242 (513)558-7544:

Waggenspack, Gerard A., M.D. (AM) Neuroradiology/Radiotogy Univ. of Texas Medical Branch 2248 Sutton Road (Home) York, PA 17403 (409)761-2230:

Wollin, Ernest, M.D. (Joan) (AM) Lake Imaging Ctr. P.O. Box 895128 (Home) Leesburg, FL 34789-0128 (904)787-5858:

Waldon II, Robert, M.D. (Carol) (AM) Richland Memorial Hospital 1420 Adger Road (Home) Columbia, SC 29205 (803)765-6998:

Wortzman, George, M.D. (Glory) (AM) Mt Sinai Hospital 600 University Ave (Office) Toronto, ON M5G 1X7 Canada (4t6) 586-4445:

Wallman, James K., M.D. (Bonnie) (AM) 15 West Sunset Drive (Home) Redlands, CA 92373 (714)793-6347:

Wright, David C., M.D. (Ann Wright) (AM) Longview Radiologists 1020 1lth Avenue (Office) Longview, WA 98632 (206)425-5131:

Weathers, Susan, M.D. (Rich) (AM) Baylor College of Med, VA Medical Center 2801 Jarrard (Home) Houston, TX 77005 (713)795-7439:

Wycliffe, Nathaniel D. (AM) Dept of Radiology Sacred Heart Hospital 900 Seton Drive (Office) Cumberland, MD 21502 (301)759-5132:

Yune, Heun, M.D. (Kay) (AM) Radiology Indiana Univ Medical Ctr. 926 W Michigan St. (Office) X-64 UH Indianapolis, IN 46223 (317)274-1846: Zeifer, Barbara A., M.D. (AM) 15 W. 72nd Street, 21-S (Home) New York, NY 10023 212/874-5656 Zimmer, Jerald, M.D. (AM) 970 Browers Point (Home) Woodmere, NY 11698 Zimmer, Alan E., M.D. (AM) 83 Addison Drive (Home) Short Hills, NJ 07078-1831 201/564-6099 Zimmerman, Robert, M.D. (Dianne) (AM) Radiology Univ of Pa 34th and Spruce Sts (Office) Philadelphia, PA 19104 (215)662-3037: Zinreich, James, M.D. (Eva) (AM) Neuroradiology Meyer 8 140 John Hopkins Hospital 600 N Wolfe St (Office) Baltimore, MD 21205 (301)955-6175: Zizmor, Judah, M.D. (SM) 225 W 86th St #904 (Home) New York, NY 10024 Zonneveld, Frans W., Ph.D. (Frans) (AS) Dept of Radiology University Hospital Catharijnesingel 101 (Office) P.O. Box 16250 Utrecht, 3500 CG The Netherlands (313)03%2164:

S 233

European Society of Head and Neck Radiology Prof. em. Paul E. Andersen Blichersvej 37 DK-5230 Odense M Denmark

Professor Barbara Carter, M.D. 171 Harrison Avenue MA 02111 Boston USA

Dr. J . A . M . de Groot Oudegracht 313 NL-3511 PB Utrecht The Netherlands

Dr. Brigitte Appel AZ. Middelheim, Radiologie Lindendreef 1 B-2020 Antwerpen Belgium

Dr. J, K. Casselman Ernest Solvaisstr, 23 B-2300 Kessel Belgium

Dr. R . G . M . de Slegte Radiology, Acad. Ziekenhuis Postbus 7057 NL-1007 MB Amsterdam The Netherlands

Dr.

J. A. Castelijns Free University Hospital De Boelelaan t t 17 NL-1081 HV Amsterdam The Netherlands

Dr,

W. Bautz Institut ftir Rad. Diagnostiek, Tech. Univ. Ismaningerstrasse D-8000 Miinchen Germany Dr.

Hans Bergstedt Diagnostisk radiologi Karolinska sjukhuset S-104 01 Stockholm Sweden Dr. med. Hilmar Bongers Radiol. Klin. Univ. T0bingen R6ntgenweg 11 D-7400 Tiabingen Germany Professor Pierre Bourjat Serv. de Radiologie I - Hopital Central C.H.U. F-67000 Strasbourg France Dr.

Sam Bri~nner Gentofte University Hospital DK-2900 Hellerup Denmark Dr~

Francois Busy Imagerie, Centre Hop.Louise Michel Quarrier du Canal, Courcouronnes F-91014 Evry Cedex France Dr. med. Wolfgang B/ihren Abt. VIII Bundeswehrkrankenhaus Ulm Oberer Eselsberg 40 D-7900 Ulm Germany Professor G. Canigiani de Cerchi Zentrales Institut fiir Radiodiagnostik Alser Strasse 4 A-1090 Wien Austria

Professor B. A. den Herder Keverberg 68 NL-I082 BE Amsterdam The Netherlands

Dr.

Dr.

D. Charneau 14, rue des Roses F-67100 Strasbourg France

J. L. Dietemann Serv. Nuerorad. Hosp. Cir. 1 Place de l'Hopital F-67005 Strasbourg Cedex France

Dr,

G. R. Cherryman Diagn Radiol, Royal Marsden Hosp. Downs Road Surrey SM2 5 PT Sutton U.K. Professor Antonio Chiesa Dept of Radiology Spedali Civili 1-25178 Brescia Italy

Dr.

P. A. Dimopoulos Department of Radiology University of Patras Patras Greece Dr.

Georges Dooms Serv. Radiol. Clin. Univ. Saint-Luc 10, Avenue Hippocrate B-1200 Bruxelles Belgium

Dr,

E. Claus Med. Centrum St. Jacobsmarkt 49 B-2000 Antwerp Belgium

Professor Dominique Doyon H6p. de Bicetre, Radiologie 78, rue du G6nbral Leclerc F'-94275 Kremlin Bicetre France

Professor Claus Claussen Dept Diagn Radiology, University Hosp. Hoppe-Seyler Str. 3 D-7400 Ttibingen Germany

B. Duvoisin Centre Hospitaier Universitaire CH-1011 Lausanne Switzerland

Professor G. Cornelis Serv Radiol. Clin, Univ. Saint-Luc Av. Hippocrate B- 1200 Bruxelles Belgium

Docent Sune Ericson Radiological Department L~inssjukhuset Ryhov S-551 85 J6nk6ping Sweden

Dr.

Professor Giovanni Ettorre Instit. di Radiol. dell' Univ. Policlinico - Piazza G. Cesare 1-70124 Bari Italy

Henk Damsma Afd. Radiodiagnostiek, Academ. Ziekenhus Heidelberglaan 100 NL-3584 GV Utrecht The Netherlands

Dr,

S 234 Professor Ugo Fisch Universit~tsspital Ziirich, ORL Klinik R~imistrasse 100 CH-8091 Ziirich Switzerland

Professor JP Haas Radiol. Institut Pacelliallee 4 D-6400 Fulda Germany

Dr. Nicole Freeling University Hospital Groningen Oostersingel 59 NL-9713 EZ Groningen The Netherlands

Professor William Hanafee, M.D. Dept. of Radiological Sciences UCLA Medical Center CA 90049 Los Angeles USA

Professor Kurt-Walter Frey Elisabethstrasse 48/5 D-8000 M~inchen Germany

Dr. med. Christian Hannig Sckellstrasse 3 D-8000 Miinchen Germany

Professor H. W. Frommhold Dept. of Radiotherapy, University of Freiburg Hugstetterstrasse 55 D-7800 Freiburg Germany

Dr. Mats Haverling Dept. of Diagnostic Radiology Karolinska sjukhuset S-10401 Stockholm Sweden

Dr. G. Garand ORL CHU Bretonneau Tours Tours France

Dr. Paul Held Residenzplatz 7 D-8390 Passau Germany

Dr. Jacques Giron C.H.U. Purpan F-31-054 Toulouse France Dr. Stephen J. Golding Dept Radiology, The Churchill Hospital Old Road, Headington OX3 7LJ Oxford U.K. Dr. Norbert Gritzmann Zent. Inst. Radiodiagn. Allg. Krankenhaus Alser Strasse 4 A-1090 Wien Austria Dr. Carmen R. Guirado Instit de Tomodensitometria Muntaner, 239 entlo A E-08021 Barcelona Spain Dr. Renate Gustorf-Aeckerle Katharinenhospital Kriegsbergstrasse 60 D-7000 Stuttgart 1 Germany

Professor Anders Hemmingsson Dept. of Diagnostic Radiology University Hospital S-75185 Uppsala Sweden Dr. MJ Hendriks Jan Willem Frisostraat 28 NL-3583 JT Utrecht The Netherlands Dr. David J. Howard Inst. of Laryngology and Otology Gray's Inn Road WC 1X 8 DA London United Kingdom Doc. Annika Isberg Mosebacke Torg 6 S- 11646 Stockolm Sweden Dr. C. Jardin Fondation Rothschild - Radiologie 25, rue Manin F-75019 Paris Cedex 19 France Dr. WD Jeans Radiodiagn. Bristol Royal Infirmary BS2 8HW Bristol U.K.

Dexter Johnson, M.D. 2520 Magnolia Blvd. W Seattle WA USA Daniel H. Johnson, M.D. Jefferson Imaging Centre 3434 Houma Blvd Metairie Lousiana USA Dr. Birna Jonsdottir X-ray dept. Borgarspitalinn Slettuveg 103 Reykjavik Iceland Professor Jens J6rgensen Dept Radiol. Kommunehospital DK-8000 Aarhus Denmark Dr. Gabriella Kahle Academic Hospital St~idtische Klinik D-6400 Fulda Germany Professor Joseph Ken6z 14 Kaniszai Str 35 H-1114 Budapest Hungary Dr. Rainer Klier Dept Diagn Radiology, University Hosp. Hoppe-Seyler Strasse 3 D-7400 Ttibingen Germany Dr. Hans J.J. Kouwenberg Twentenborg Ziekenhuis Almelo Postbus 7600 NL-7600 SZ Almelo The Netherlands Dr. Odo K6ster Radiolog. Universit~tsklinik Sigmund Freud Strasse 25 D-5300 Bonn-Venusberg Germany Dr. G.H.M. Landman Postelstraat 2 NL-5602 EE Lieshout The Netherlands Dr. Sven G. Larsson Dept. of Diagnostic Radiology University Hospital S-75185 Uppsala Sweden

S 235 Dr. Stephan-Fir Lemahieu Freren Fonteinstraat 8 B-8000 Brtigge Belgium Priv.Doz.Dr.med Martin Lenz Abt. Radiologische Diagnostik Otfried-Miiller Strasse D-7400 Tfibingen Germany Dr. M. Leonardi Ospedali Civile 1-33100 Udine Italy Dr. Glyn Lloyd Royal Nat.Throat, Nose and Ear Hospital Gray's Inn Road WC 1X 8 DA London U.K. Dr.med. L. Lopez4bor Hosp.Provincial de Sant.de Compostela C/Ramon Baltais/n Santiago de Compostela Spain Assoc.professor Robert Lufkin, M.D. Dept. of Radiological Sciences UCLA Medical Center CA 90024 Los Angeles USA Dr. Valerie J. Lund 19 Cherwell Court Broom Park Teddington, Middelsex TW 11 9RT United Kingdom Dr. Gertrude Maatman Stationsweg 19 NL-6861 EA Oosterbeek The Netherlands Dr. P Mathurin Serv.Radiol. Clin Saint-Luc Avenue Hippocrate 10 B- t 200 Bruxetles Belgium Professor Gilbert Mazy Clin Univ St-Luc,Service de Radiologie Av.Hippocrate 10 B-1200 Bruxelles Belgium Dr. Philippe Meriot H6pital Augustin-Morvan F-29285 Brest France

Professeur Jean-Frangoi Moreau Serv de Radiotogie, H6pital Necker 161 rue de S6vres F-75015 Paris France

Dr.med. Otto Pohlenz Abt Strahlendiagn, Allgem Krankenhaus St. Lohmtihlenstrasse 5 D-2000 Hamburg 1 Germany

Dr. Catharina Muren Ella Parksvhg 5 S-18340 Taby Sweden

Dr. Thomas Powell Dept. of Neuroradiology Glossop Road SI0 2JF Sheffield United Kingdom

Prof.Dr.med. Ulrich M6dder Inst.f.Rtg diagn. Univ Dtissetdorf Moorenstr. 5 D-4000 Dtisseldorf Germany

Dr.med. Sayed A.A. Qaiyumi Konstantin Gutschowstrasse 8 D-3000 Hannover 61 Germany

Dr. Christoph Ozdoba Radiol.klin. Univ Tiibingen R6ntgenweg 1t D-7400 Tiibingen t Germany

Professor Klaus Reisner St-Vincentius-Krankenhaus Stidenstrasse 32 D-7500 Karlsruhe t Germany

Professor, Dr.Med H.J. Peter Academic Hospital Sthdtische Klinik D-6400 Fulda Germany

Dr. P. Rodigro Avda E1 Ferrol 15 E-28029 Madrid Spain

Dr. Peter Phelps Royal National Throat Nose and Ear Hospital Gray's Inn Road WC1X 8DA London U.K. Dr. L. Picard Hopital St Julien Case Officielle 34 1=-54037 Nancy Cedex France Dr. J.-D. Piekarski Fondation Rothschild - Radiologie 25, rue Manin F-75019 Paris Cedex 19 France Prof.Dr. Uwe Piepgras Institut ftir Neuroradiologie Universitfit des Saarlandes D-6650 Homburg/Saar Germany Dr. Marie-Madel Plantet Centre Ren6 Hugkems 35, Rue Dailly Saint Cloud France

Dr. Roser Roig Instituto de Tomodensitometria Avenida de Madrid 140 4°3a E-08028 Barcelona Spain Dr, RR Rovira C/.Borrell, 292 I°C E-08029 Barcelona Spain Professor H. Rovsing Rtg-avd, Hvidovre Hospital Kattegfird All6 30 DK-2650 Hvidovre Denmark Dr. DA Ruefenacht Gesellschaftstrasse 14 CH-3012 Bern Switzerland Professor U. Salvolini Ospedale Civile Umberto I Corso Stamira 49 1-60100 Ancona Italy Professor Eric Samuel 1I, The Paddock, Stella St Sandton, Transvaal South Africa

S 236 Dr.

Othmar Schubiger Seestrasse 220 Klinik im Park CH-8027 Ztirich Switzerland Dr.med. Martin Skalej Radiol.klin. Univ.Tiibingen R6ntgenweg 11 D-7400 Ttibingen Germany Professor Peter Sore, M,D. Mount Sinai Med.Center One Gustave L.Levy Place NY 10029 New York USA Dr. Soutter Hopital du Moenberg F-68070 Mulhouse Cedex France Dr. CR Staalman Zijdelaan 30 NL-2594 BW Den Haag The Netherlands Dr, J. Michael Stansbie Walsgrave Hospital Clifford Bridge Road Walsgrave Coventry U.K, Dr. Hannibal S6kjer Regionsjukhuset Diagn Radiologi S-58185 Link6ping Sweden Professor Mutsumasa Takahashi Dept of Radiology, Kumamoto Univ. 1-Chome, Honjo 860 Kumamoto Japan Dr. J.L. Termote Kraaistraat 3 B-2508 Kessel Belgium

Professor Terrahe Katharinenhospital Kriegsbergstrasse 60 D-7000 Stuttgart 1 Germany

Karin Wadin Dept. of Diagnostic Radiology University Hospital S-75185 Uppsala Sweden

Dr.med. Fernando Torrinha Rua S. Sebastiao da Pedreira 82-20E P- 1000 Lissabon Portugal

Docent Per-Lennart Westersson 34 Copper Woods NY 14534 Pittsford USA

Dr. Manuel Trujillo Peco Narvaez 29 E-28009 Madrid Spain

Dr. Hermann Wilbrand Dept. of Diagnostic Radiology University Hospital S-75185 Uppsala Sweden

Dr.

Professor Anton Valavanis Neuroradiology University Hospital Ztirich Franenklinikstrasse 10 CH-8091 Ziirich Switzerland

Dr.med. Anita Wuttge-Hannig Sckellstrasse 3 D-8000 Mtinchen Germany

Professor Galdino E. Valvassori, M.D. 55 East Washington Street IL 60602 Chicago USA

Dr. Friedhelm Zanella Univ.klinik, Radiol,Inst. Josef Stelzmannstrasse 9 D-5000 K61n 41 Germany

Prof.Dr. Paul F.G.M. van Waes Afd.Radiodiagnostiek, Academ.Ziekenhus Heidelberglaan 100 NL-3508 GA Utrecht The Netherlands

Dr. W. Zaunbaner Kantonsspital CH-9007 St. Gallen Switzerland

Dr. Francis Veillon Serv. de Radiot. 1, H6p. Central B,P. No 426 F-67091 Strasbourg France Dr. Jacqueline Vignaud Fondation Rothschild - Radiologie 44, Avenue Mathurin Moreau F-75019 Paris France Dr. Thomas Vogl Radiol-Klin. der Universit/it Mfinchen Marchioninistrasse 15 D-8000 Mtinchen Germany

Ph.D. Frans W. Zonneveld Oranjestraat 35 NL-5091 BK Middelbeers The Netherlands

S 237

European Society of Neuroradiology Full Members Austria Dr. Hildegard B6hm-Jurkovic Neuroradiologie Wagner-Jauregg-Krankenhaus A-4020 Linz Dr. Michael Brainin Neurologische Abteilung NiederSsterreichisches Landeskrankenhaus HauptstraBe 2 A-3400 Klosterneuburg Dr. Franz Ebner Radiologische Klinik Karl-Franzens-Universitgt Graz Landeskrankenhaus Auenbruggerplatz 9 A-8036 Graz Dr. Karl Gindl Krankenhaus Mistetbach Liechtensteinstrage 67 A-2130 Mistelbach Prim. Dr. Mario-Max Grobovschek Landesnervenklinik Salzburg R6ntgeninstitut Ignanz-Harrer-Strage 79 A-5020 Salzburg Prof. Benno Hammer Abteilung Neuroradiologie Radiologisches Institut Wagner-Jauregg-Krankenhaus Wagner-Jauregg-Weg 15 A-4020 Linz Prim. Dr. Helge Haselbach R6ntgendiagnostisches Zentralinstitut/Neuroradiologie Landeskrankenhaus Klagenfurt St. Veiter Str. 47 A-9020 Klagenfurt Dr. Sabine Lang Nieder6sterreichische Landesnervenklinik Hauptplatz 2 A-3400 Klosterneuburg Dr. Hermann Leitner Hintzerstrage 6/10 A-1030 Wien Holt. Prim. Dr. Hermann M6sl Franz-Schalk-Str. 24 A-5020 Salzburg

Dr. Thomas Reisner Neuroradiologische Abteilung Neurol. Univ. Klinik Lazarettgasse 14 A-1090 Wien

Dr. Pierre Flandroy Service de Radiologie Centre Hospitaler Universitaire de Liege B-4000 Sart Tilmar Par Liege 1

Dr. Peter Samec Neuroradiologische Abteilung Neurol. und Psych. Universitgtsklinik Lazarettgasse 14 A-1090 Wien

Dr. Philippe Herve Service de Neuroradiologie Clinique St. Joseph B-4000 Liege

Doz. Dr. Erwin Schindler Neurochirurgische Universitgtsklinik W~ihringer G~rtel 18-20 A-1090 Wien Dr. Gerhard Schneider Universitgtsklinik ffir Radiologie Landeskrankenhaus Auenbruggerplatz 1 A-8036 Graz Dr. Siegfried Trattnig Abt. fiir Diagnostische Radiologie II. Med. Universit~itsklinik Garnisong. 13 A-1090 Wien

Belgium Dr. Brigitte Appel Chef du Department de Neuroradiologie-C.T.-N.M.R. A,Z. Middelheim Lindendreef 1 B-2020 Antwerpen Prof. Daniele Bateriaux Service Radiologie HSpital Erasme 808, route de Lennik B-1070 Bruxelles Dr. Jan Casselman Az St. Jan Ruddershove 10 B-8000 Brugge Dr. Jacques Collignon Centre Hospitalier Universitaire de Liege B-4000 Sart Tilman Par Liege Prof. Georges Cornelis Clinique Universitaire St. Luc Avenue Hippocrate 10 B-1200 Bruxelles Dr. Georges Dooms Clinique St. Luc 10. Avenue Hippocrate B-1200 Bruxelles

Dr. Francine Hotton Service de Radiologie H6pital Universitaire St. Pierre 322, Rue Haute B-1000 Bruxelles Prof. Louis Jeanmart Service Radiodiagnostic Institut Border Rue Heger-Bordet 3 B-1000 Bruxelles Dr. Marc Lemort Inst. Jules Bordet 1, Rue Heger Bordet B-1000 Bruxelles Dr. J.P.Mathurin Neuroradiologie Clinique Universitaires St. Luc Avenue Hippocrate 10 B-1200 Bruxelles Dr. Paul M. Parizel Department of Radiology Antwerp University Hospital Wilrijkstraat 10 B-2520 Edegem Prof. Roland Potvliege Service de Radiologie H6pital Universitaire Brugmann 4, Place A. Van Gehuchten B-1020 Bruxelles Dr. Georges Rodesch Radiology Department H6pital Erasme 808, route de Lennick B-1070 Brussels Prof. Andre Thibaut Service de Radiologie Centre Hospitalier Universitaire de Liege B-4000 Sart Tilman Par Liege 1 Dr. Linda Ticket Radiology Department Universitar Ziekenhuis Brugmann 4, Van Gehuchtenplein B-1020 Bruxelles Dr. Willy Van Damme 2 A, Noordstraat B-9600 Ronse (Renaix)

S 238 Prof. Eric G.M.E Van de Velde Universitair Ziekenhuis Radiologie De Pintelaan 185 B-9000 Gent Dr. Jean-Hubert Vandresse Radiologie Avenue des Ducs 45 B-1970 Wezembeek Dr. Paul Verheggen Clinique Reine Fabiola Montignies/Sambre B-Charleroi Prof. Guy Witms Department of Radiology University Hospital K.U. Leuven Herestraat 49 B-3000 Leuven

Bulgaria Prof. Dimitri Kitov Rue Nicolas Galbov BG-4000 Plovdiv

CSFR Dr. Jiri Bret Pod Devinem 40 CS-15000 Praha 5 Dr. Josefa Bohutova Radiodiagnostic Clinic ILF FN Bulovka, Budinova 2 CS-18000 Praha 8 Prof. J. Jirout Katerinskfi 30 CS-12000 Praha Prof. Pave1 Kalvach Department of Neurology Postgraduate Medical School Videnska 800 CS-14059 Praha 4 Dr. Ludmila Krausova Neurologicka Klinika Charles University Katerinska 30 CS-12000 Praha 2 Dr. Karel Lewit Neurologicka Klinika Srobarova 50 CS-12000 Praha i0 Dr. Jozef Mihale Neurolog. Klin., Med. Fak. Comenius University Mickiewiczova, 13 CS-81369 Bratislava Dr. Sasa Nettl Neurological Clinic Charles University CS-50002 Hradec Kralove

Prof. Milan Roth Radiodiagnostic Clinic Medical Faculty Hospital Pekarska 53 CS-65691 Brno

Dr. Henry Artmann Institut fiir Strahlendiagnostik Leopoldina-Krankenhaus Gnstav-Adolf-Strage 8 D-8720 Schweinfurt

Dr. Miroslav Smisek Neurologic Clinic NSP Akad. L. Derera Limbova 5 CS-833 05 Bratislava

Dr. Albrecht Aulich Neuroradiologische Abt. der MNR-Klinik Universiffttskliniken MoorenstraBe 5 D-4000 Diisseldorf 1

Prof. Pavel Strnad Head of the Clinic of Neurology FNsP Brno-Bohunice Jihlavskfi 100 CS-63900 Brno Prof. Lubos Vyhnanek Radiological Clinic of the Charles University U Nemocnice 2 CS-12808 Praha 2

Denmark Dr. AxeI Fahrenkrug Hattesens Alte 4 DK-2000 Frederiksberg Prof. Carsten Glydensted Department of Neuroradiology Aarhus Kommunehospital DK-8000 Aarhus Dr. Harald Hataburt Department of Neuroradiology Aarhus Kommunehospital DK-8000 Aarhus Dr. Agnete Karle Tagestorp 2 DK-2820 Gentofte Dr. Erik Aaris Langebaek Neuroradiological Department Odense Hospital DK-5200 Odense Dr. Johannes Praestholm Skovbrinken 21 DK-3450 Allerod Dr.J.Nepper-Rasmussen R6ntgendiagnostik afd. Odense Sygehus DK-5000OdenseC Dr. Erling Ratjen Egetundsvej 8 DK-8240 Risskov

Federal Republic of Germany Prof. Agnolo Lino Agnoli Abteilung fiir Neuroradiologie Klinikum der J. L. UniversitM Am Steg 22 D-6300 Giessen

Dr. Herbert Backmund Max-Planck-Institut fiir Psychiatrie Kraepelinstrage 10 D-8000 Miinchen 40 Prof. Hartmut Becker Abt. Neuroradiologie Med. Hochschule Konstanty-Gutschow-Strage 8 D-3000 Hannover 61 Prof. Heribert Betz Rudolf-Stratz-Weg 13 D-6900 Heidelberg Prof. S.Bockenheimer Neuroradiologie Krankenhaus Nordwest Steinbacher Hohl 2-26 D-6000 Frankfurt 90 Dr. Friedhetm Brassel Abteitung ftir Neuroradiologie Med. Hochschule Hannover Konstanty-Gutschow-Strage 8 D-3000 Hannover 61 Doz. Dr. sc. F. Deckert Klinik fiir Radiologie Karl-Marx-Universit~it Liebigstrage 20a D-7010 Leipzig Dr. G.Dfisterbehn Rotdornweg 4 D-2906 Wardenburg Dr. Klaus Effter Radiologische Abteilung des Bezirkskrankenhauses f. Neurologie u. Psychiatrie Hufelandstrage 15 D-8143 Arnsdorf Priv.-Doz. Dr. Helga GrN'in von Einsiedel Abteilung ffir Neuroradiologie Institut fiir R6ntgendiagnostik d. Techn. Universit/it Klinikum rechts der Isar M6hlstrage 28 D-8000 Miinchen 80

S 239 Dr. Georg Fahrendorf Zentralinstitut ffir Radiolog. Diagnostik und Neuroradiologie Evangelisches Krankenhaus D-2900 Oldenburg

Prof. K. K6hler Klinik ftir Radiologie Medizinische Akademie Dresden Fetscherstrage 74 D-8019 Dresden

Dr. Hans-Christian Nahser Abteilung Neuroradiologie Alfried-Krupp-Krankenhaus Alfried-Krupp-Strage 21 D-4300 Essen 1

Prof. B. J. Othmar Fiebach Zentr. Strahlendiagnostik und Neuroradiologie St/~dt. Kliniken Duisburg Z. d. Rehwiesen 9 D-4100 Duisburg 1

Prof. Knut Kohlmeyer ZentralinstittR far Seelische Gesundheit Postfach 122120 D-6800 Mannheim 1

Prof. Uwe Piepgras Institt~t ft~r Neuroradiologie Universit~it des Saarlandes Med. Fakultgt D-6650 Homburg/Saar

Dr. Frank Koschorek Abteilung ffir Neuroradiologie am Klinikum der J.W.-Goethe-Universit/it Schleusenweg 7-10 6000 Frankfurt/Niederrad

Dr. Kurt Ringel Radiolog. Zentrum R6ntgendiagnostik Zentralklinikum Augsburg Stenglinstrage 2 D-8900 Augsburg

Prof. Konrad Kretzschmar Abteilung Neuroradiologie J 5 Zentralinstitut ftir Seelische Gesundheit Postfach 122120 D-6800 Mannheim 1

Prof. Klaus Sartor Arztl. Dir. d. Abt. Neuroradiologie Universitfitsklinikum Im Neuenheimer Feld 400 D-6900 Heidelberg

Prof. D. Kfihne Abt. Neuroradiologie Alfried-Krupp-Krankenhaus Alfried-Krupp-Strage 21 D-4300 Essen 1

Prof. Karl Heinz Schiffer Georg-B/~chner-Strage 112 D-6501 Mainz-Hechtsheim

Prof. G. Freitag Klinik far Radiologie IVied. Akademie Magdeburg Leipziger Strage 44 D-3090 Magdeburg Dr. Holger Christian Grau Abteilung ffir Neuroradiologie Evangelische Krankenanstalten Duisburg-Nord Fahrner StraBe 133 D-4100 Duisburg 11 Dr. Dipl.-Biol. W. Grodd Abteilung ftir Neuroradiologie der Universit~t Kliniken Schnarrenberg Hoppe-Seyler-Strage 3 D-7400 Tfibingen 1 Dr. Renate Gustorf-Aeckerle Neuroradiolog. Institut Katharinenhospital KriegsbergstraBe 60 D-7000 Stuttgart 1 Prof. Hans Hacker Abt. f. Neuroradiofogie am Klinikum der J.-W.-Goethe-Universit/it Schleusenweg 7-10 D-6000 Frankfurt-Niederrad Prof. Lothar Heuser Institut ftir Radiologie und Nuklearmedizin der Ruhr-Universit~it Knappschaftskrankenhaus D-4630 Bochum 7 Dr. Adolf Hintze Horststrage 38 D-2160 Stade Dr. Horst Hirschbiegel Alt Pempelfort 4 D-4000 Dt~sseldorf Dr, Heike Klusemann Abteilung ft~r Neuroradiologie der Universit~itskliniken Langenbeckstrage 1 D-6500 Mainz Prof. R. D. Koch Klinik ffir Neurologie und Psychiatrie Med. Akademie Magdeburg Leipziger Strage 44 D-3090 Magdeburg

Prof. R. Lehmann Klinik u. Poliklinik ft~r Psychiatrie u. Neurologie Barlich Medizin (Charit6) der Humboldt-Universit/~t zu Berlin Schumannstrage 20 D-1040 Berlin Priv.-Doz. Dr. Bernd Ludwig Radiolog. Gemeinschaftspraxis Dres. Hentschel/Krt~ger/Ludwig Magin Am Brand 22 D-6500 Mainz Dr. Harry Marcu Zentrum der Radiologie Klinikum der J.-W.-Goethe-Universit~it D-6000 Frankfurt 70 Dr. H. P. Molsen Strahlenklinik und Poliklinik Rudolf Virchow Freie Universit~it Berlin Spandauer Damm 130 D-1000 Berlin 19 Dr. Wibke Mfiller-Forell Abteilung ffir Neuroradiologie der Universitgtskliniken Langenbeckstrage 1 D-6500 Mainz Prof. M. Nadjmi Abt. f. Neuroradiologie in der Kopfklinik der Universit~it Josef-Schneider-Strage 11 D-8700 Wt~rzburg

Priv. Doz. Dr. Rt~diger C. Schmidt Institt~t ft~r Neuroradiologie Krankenanstalten Gilead Burgsteig 13 D-4800 Bielefeld 13 Priv. Doz. Dr. Gerhard Schroth Abteilung fi~r Neuroradiologie Universit~itsspital Z/Jrich Frauenklinikstrage 10 CH-8091 Zi~rich Prof. Martin Schumacher Abteilung R6ntgendiagnostik Sektion Neuroradiologie Klinikum der Albert-Ludwigs-Universit/~t Hauptstrage 5 D-7800 Freiburg i.Br. Dr. Ralf-Sigmar Simon Weitlinger StraBe 13 D-8500 Nfirnberg 60 Prof. Franz Sindermann Waaghausstrage 1 D-7950 Biberach a. d. Rig Priv,-Doz. Dr. L.Solymosi R6ntgenabteilung Neurochirurgie Sigmund-Freud-Strage 25 D-5300 Bonn 1 Dr. Harald Steinhoff Radiotogische Klinik Abteilung Neuroradiologie Klinikum Gro6hadern Marchionistrage 15 D-8000 Mfinchen 70

S 240 Prof. Peter Stoeter Abteilung ftir Neuroradiologie St. Elisabethen-Krankenhaus Elisabethstral3e 15 D-7980 Ravensburg Prof. Armin Thron Neuroradiologie Klinik fiir Radiolog. Diagnostik der RWTH Pauwelsstrage 30 D-5100 Aachen Dr. Frank Thun Neuroradiologie d. Radiolog. Inst. der Universit~itskliniken Josef-Stelzmann-Str.9, Haus 12 D-5000 K61n 41 Prof. Klaus Tornow Neuroradiologische Abteilung Klinikum Mannheim der Universitgt Heidelberg Theodor-Kutzer-Ufer 1 D-6800 Mannheim Prof. Karsten Voigt Abteitung ffir Neuroradiologie der Universitat Kliniken Schnarrenberg Hoppe-Seyler-Stral3e 3 D-7400 Ti~bingen Dr. Dimitri Vonofakos Rotes Kreuz-Krankenhaus K6nigswarterstrage 16 D-6000 Frankfurt 1 Prof. Sigurd Wende Kerschensteiner Strage 17/19 6500 Mainz Prof. Rodger von Wickede Moltkestrage 30 D-5600 Wuppertal 1 Prof. Eberhard Zeitler Radiologisches Zentrum Abteilung Diagnostik Klinikum Ntirnberg FlurstrafSe 17 D-8500 Niirnberg Prof. H.Zeumer Abt. f. Neuroradiologie Radiologische Klinik des UKE Martinistrage 52 D-2000 Hamburg 20

Finland

Dr. Kalevi Katevuo Department of Radiology University of Turku SF-20720 Turku

Dr. Erkki M. Laasonen T6616 Hospital Helsinki University Central Hospital Topeliuksenkatu 5 SF-00260 Helsinki Dr. Raili Raininko Department of Diagn. Radiology Meilahti Hospital University Central Hospital of Helsinki SF-00290 Hetsinki

France

Dr. Michel Almeras Service de Neuroradiologie H6pital Du Marts F-72000 Le Mans Dr. Armand Aymard H6pital Lariboisi6re 2, Rue Ambroise Pare 1=-75019 Paris Dr. Chantal Bamberger-Bozo 3, Rue due Vieux Colombier F-75006 Paris Dr. Y. Bascoulergue Service de Radiologie H6pital Neuroloque 59, Boulevard Pinel F-69003 Lyon Dr. Siegfried Bien Service de Neuroradiologie H6pital Lariboisi~re 2, Rue Ambroise Pare F-75010 Paris Dr. Alessandra Biondi H6pital de La Salpetri~re 47, Boulevard de l'H6pital F-75013 Paris Prof. Daniel Binnert Neuroradiologie Centre H6pitalier Universitaire 2, Rue de l'H6pital F-21033 Dijon Cedex Dr. Alain Bonafe Service de Neuroradiologie Hgpital Purpan F-31052 Toulouse Cedex Prof. Jean Francois Bonneville Department of Neuroradiology University Hospital F-25000 Besancon Prof. Jacques Bories Service de Neuroradiologie H6pital de la Salpetri6re 47, Boulevard de l'H6pital F-75651 Paris Cedex

Dr. Serge Bracard Service de Neuroradiologie H6pital St. Julien 1, Rue Foller F-54037 Nancy Cedex Dr. Jean Paul Braun Service de Neuroradiologie Centre Hospitalier L. Pasteur F-68021 Cedex Prof. Emmanuel-Alain Cabanis Service de Neuroradiologie Centre National de Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. Marie-Th. Cabanis-Iba-Zizen Neuroradiologie H6pital des Quinze Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Prof. Jean-Marie Caille Service de Neuroradiologie Groupe Hospitalier Pellegrin-Tripode Place Amelie Raba-Leon F-33076 Bordeaux Cedex Dr. Michel Carsin Radiologie Centrale H6pital Pontchaillon F-35033 Rennes Cedex Dr. Robert Cavezian Service de Neuroradiologie Centre National d'Ophthalmologie des Quinze Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. Jacques Chiras Assistance Publique H6pitaux de Paris, Groupe Hospitalier Piti~-Salpetri6re, Service de Neuro-Radiologie Charcot 47, 83 Boulevard de l'H6pital F-75651 Paris Cedex 13 Prof. Jacques Clarisse Service de Neuroradiologie H6pital B D.H.R. Lille F-59037 Lille Cedex Dr. Patrick Courtheoux Neuroradiologie Centre Hospitalier Universitaire Avenue de la C6te de Nacre F-14033 Caen Dr. Alain Debaene Clinique Clairval Bid du Redon F-13009 Marseille Dr. Axel De Kersaint-Gilly Service de Neuroradiologie H6pital G. & R. Laennec B.P. 1005 F-44035 Nantes Cedex 01

S 241 Dr. Claude Debussche-Depriester H6pital Nord Place Victor Pauchet F-80054 Amiens Cedex Dr. H. Deramond Service de Radiologie A CHU Amiens F-80030 Amiens Cedex Dr. Jean-Louis Dietermann Service de Neuroradiologie Hospices Civils F-67091 Strasbourg Cedex Dr. Didier Dormont H6pital de la Salpetri~re 47 Boulevard de l'H6pital F-75013 Paris Prof. Dominique Doyon Service Radiologie Adulte H6pital de Bicetre 78, Rue du Gal Leclerc F-94276 Le Kremlin Bicetre Cedex Dr. Mehmet Murat Firat H6pital St. Antoine F-75012 Paris Prof. Daniel Fredy Neuroradiologie H6pital Ste. Anne Rue Cabanis F-75014 Paris Prof. Jean-Claude Froment Service de Radiologie H6pital Neurologique BP Lyon Montchat F-69394 Lyon Cedex 03 Dr. Denis Gardeur Service Neuroradiologie H6pital de la Piti6 47, Boulevard de L'H6pital F-75624 Paris Cedex 13 Dr. Andre Gaston Service de Neuroradiologie H6pital Henri-Mondor Rue du General Sarrali F-94000 Creteil Dr. Gerard Gozet 132, Boulevard de la Liberte F-59800 Lille Dr. J. E Greselle Residence Le Floie 30, Rue Marcelin Berthelot F-33200 Bordeaux Dr. Francoise Guibert-Tranier 32, Boulevard du Marechal Juin F-06800 Cagnes Sur Mer Prof. Gerard Giudicelli 10, Rue de Florac F-13008 Marseille

Dr. Kamal Haddat 41, Boulevard de Paris F-62660 Berck sur Mer Dr. Etienne Hertzog 9, Allee des Pelouses F-788170 La Celle St Cloud Dr. All Tunc Iryboz H6pital St Antoine F-75012 Paris Dr. Henri Jacques 4, Rue Schwilgue F-6740 Ilkirch-Graffenstaden Dr. Je~in-Paul Julliot Service de Radiologie Centre Hospitaler Universitaire F-59000 Lille Dr. Denis Krause 13, Rue Trubner F-67000 Strasbourg Prof. Jacques Laffont Service de Neuroradiologie Centre Hospitalier Regional Bretonneau F-37000 Tours Prof. Pierre L. Lasjaunias Neuroradiologie vasculaire H6pital Bicetre 78, Rue du General Leclerc F-94275 Kremlin Bicetre Dr. Michel Launay Appt. n ° 11519 69, Rue Dunois F75646 Paris Cedex 13 Dr. Claude Levy H6pital St. Antoine Department de Neuroradiologie Service de Radiologie 184, Rue du Fg. St. Antoine F-75012 Paris Dr. Francois Le Bras C.H.U. Pitie Salpetriere Secteur Pitie-Service Neuroradiologie 83, Boulevard de l'H6pital F-75651 Paris Cedex 13 Dr. Jacques Le Guyader Service de Radiologie Centre Hospitalier de Brest H6pital Morvan F-29279 Brest Cedex Prof. Claude Manelfe Department de Neuroradiologie Centre Hospitalier et Universitaire Purpan F-31051 Toulouse Cedex Dr. Nadine Martin 8, Rue St. Jean Baptiste De la Salle F-75006 Paris

Prof. Claude Marsault Service de Neuroradiologie Groupe Hospitalier Piti6-Salpetri~re Secteur La Piti& Pavillon Husson-Mourier 83, Boulevard de l'H6pital F-75651 Paris Cedex 13 Dr. Francesco Matozza H6pital Saint Antoine 184, Faubourg St. Antoine F-75012 Paris Prof. Jean-Jacques Merland Dpt.Neuroradiologie H6pital Lariboisi6re 2, Rue Ambroise Pare F-75010 Paris Prof. Jean Metzger H6pital de la Piti6 Service de Neuroradiologie 83, Boulevard de l'H6pital F-75634 Paris Dr. Odile Missir 30, Rue Jouffroy F-75017 Paris Dr. Daniel Mitard 7, Boulevard Luc Olivier Merson F-44000 Nantes Dr. Jacques Moret Department of Interventional Neuroradiology Foundation Rothschild 25-29, Rue Manin F-75940 Paris Cedex 19 Dr. Gerard Pasquet Service de Neuroradiologie Centre National d'Ophthalmologie des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. Claire Perfettini 52, Rue Cambronne F-75015 Paris Prof. Luc Picard Service de Neuroradiologie H6pital Saint Julien Case Officielle 34 F-54037 Nancy Cedex Dr. Guy Porret Neuroradiologie Centre National d'Ophtalmologie des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. J. P. Pruvo Service de Neuroradiologie Centre Hospitalier Regional et Universitaire H6pital B F-59037 Lille Cedex

S 242 Prof. Charles Raybaud Radiologie H6pital Nord F-I3326 Marseille Cedex 15

Dr. Alain Tournade Service de Neuroradiologie Centre Hospitalier L. Pasteur F-6802t Cedex

Dr. Zoltan Patay Kelenhegyi ut 68/a fsz. 1 H-1118 Budapest

Prof. Jacques Roland Service de Neuroradiologie H6pital St Julien Case Officielte n ° 134 F-57037 Nancy Cedex

Dr. Jacques Treil Service de Radiologie Clinique Pasteur 45, Avenue de Lombez F-31300 Toulouse

Iceland

Dr. Jacques Rosier Service de Neuroradiologie Centre Medico-Chirurgical Foch 40, Rue Worth F-92151 Suresnes Cedex

Dr. Pierre M. Trotot Institut - Pasteur H6pital 211, Rue de Vaugirad F-75015Paris

Dr. Claudine Rumeau Departement de Neuroradiologie La Timone Marseitle Boulevard Jean Moulin F-13385 Marseille Cedex 5 Prof. Georges Salamon Service de Neuro-RadioIogie et de Radiologie Vasculaire Centre Hospitalier Regional et Universitaire de Marseille Groupe Hospitalier de la Timone Boulevard Jean Moulin F-13385 Marseille Cedex 5 Dr. Jean-Jacques Serres Bloc "Le Galatee" 80, Avenue du Boig de Cythere F-06000 Nice Dr. Jackle-W. Soutter Service de Radiologie "C" Neuroradiotogie H6pital du Moenchsberg 20, Rue d. Dr. Laennec F-68070 Mulhouse Cedex

Dr. Christian Viaud Centre de Radiologie De Maubeuge 11, Rue de la Croix F-59600 Maubeugc Dr. Jacqueline Vignaud Service de Radiologie Fondation A. de Rothschild F-75940 Paris Cedex 19 Prof. Constantin Vrousos Le Rozat F-38330 Saint Ismier Prof. Auguste Wackenheim Service de Neuroradiologie Hospices Civites F-67091 Strasbourg Cedex Prof. med.Georg Z611ner Institut de Radiologie I Hospices Civils F-67091 Strasbourg Cedex

Greece

Dr. Olafur Kjartansson R6ntgendeild Landspitalinn IS-101 Reykjavik

Italy Dr. Filippo Aiello Via Notarbartolo 49 I-Palermo Dr. Nicoletta Anzalone Servizio di Neuroradiologia Ospedale San Raffaele Via Olgettina 60 1-20132 Milano Dr. Renato Apolito Hosp. Nuovo Pellequini 1-80142 Napoli Dr. William Auteri Servizio di Neuroradiologia Ospedali Riuniti G. Melacrino e F. Bianchi Via G. Melacrino 1-89100 Reggio di Calabria Dr. Marcello Bartolo Via Medaglie d Oro 60 1-87100 Cosenza Dr. Pellegrino Bassi Via Rasori 5 1-43100 Parma

Dr. Carmelita Stoffels Neuroradiologie Centre National des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12

Dr. Athanasios Dimitriadis A.H.E.P.A. University Hospital GR-ThessaIoniki

Dr. Stefano Bastianello Neuroradiological Section State University of Rome "La Sapienza" Viale Dell Universita 30 1-00185 Roma

Dr. Jean Tamraz Centre Hospitalier National des Quinze-Vingts Service de Neuroradiologie F-75012 Paris

Hungary

Dr. Giorgio Belloni Via A. Diaz 3 1-24100 Bergamo

Prof. Jacques Theron Service de Neuroradiologie CHU C6te de Nacre F-14040 Caen Cedex Dr. Martin Thibierge Service de Neuroradiologie Center Hospitaier National des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Prof. Jacques Thiebot Neuroradiologie C.H.U. Charles Nicolle 1, Rue de Germont F-76031 Rouen Cedex

Dr. Gy6rgy Deak Orszagos Idegsebeszeti Tudomanyos Intezet Amerikai ut 57 l-i- 1145 Budapest XIV Dr. Jozsef Kenez Neurological Clinic of Semmelweis Medical University H-1145 Budapest

Dr. Alberto Beltramello Servizio di Neuroradiologia Ospedale Civile Maggiore 1-37126 Verona Dr. Aldo Benati Servizio di Neuroradiologia Ospedale Civile Maggiore 1-37126 Verona

Dr. Ferenc Lanyi National Institute of Neurosurgery Department of Neuroradiology Amerikai ut 57 H-1145 Budapest

Dr. Lorenzo Bernardi Instituto di Neuroradiologia Ospedale Civile 1-36100 Vicenza

Dr. Istvan Nagy Baros Gabor 50 sr. H-1165 Budapest XIV

Dr. Vittorio Bernasconi Via Fioraventi 33 1-20100 Milano

S 243 Dr. Francesco-P. Bernini Instituto di Neurochirurgia Cattedra di Neuroradiologia Universita di Napoli V. le Colli Aminei 21 1-80131 Napoli Dr. Alberto Bizzi 10201 Grosvenor PI, Apt. 914 USA Bethesda, MD 20852 Dr. Edoardo Boccardi Servizio di Neuroradiologia Ospedale Maggiore Niguarda Piazza Ospedale Maggiore 3 1-20162 Milano Dr. Guiseppe Bonatdi Servizio di Neuroradiologia Ospedale Riuniti Largo Barozzi 1 1-24100 Bergamo Dr. Maurizio Bracchi Instituto Nazionale Neurologico "C. Besta" Via Celoria 11 1-20133 Milano Prof. Boris Gianni Bradac Cattedra di Neuroradiologia delI Universita di Torino Ospedale Molinette Via Cherasco 15 1-10126 Torino Dr. Vincenzo Branca Servizio di Neuroradiologia Ospedale Maggiore Niguarda "Ca Granda" 1-20162 Milano Dr. Francesco Caffarelli Servizio di Neuroradiologia Ospedale Riuniti G. Melacrino e F. Bianchi 1-89100 Reggio di Calabria

Dr. Gianfranco Cristi Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40139 Bologna

Dr. Massimo Feliciani Neuroradiology Service Dpt. of Neurosciences University "La Sapienza" 1-00185 Rome

Dr. Carlo Cimino Instituto Nazionale Neurologico "C. Besta" Via Celoria 11 1-20133 Milano

Dr. Daniele Fiore Via Nazareth 33 1-35100Padova

Dr. Sossio Cirilto Servizio di Neuroradiologia Instituto di Radiologia 11 Nuovo Policlinico Via Pansini 5 1-80131 Napoli

Dr. Francesco Finizio Neuroradiologia Ospedale Maggiore Via Attura 3 1-40139 Bologna Dr. Claudio Fonda Servizio di Neuroradiologia dell'Universita di Firenze I-Firenze

Dr. Nadia Colombo Servizio de Neuroradiologia Ospedale Niguarda Piazza Ospedale Maggiore 3 t-20162 MiIano

Dr. Elene Gaidolfi Servizio di Neuroradiologia Ospedale Civite T 0 1-10100 Torino

Dr. Rodolfo Daidone Clinica Neurologico dell'Universita di Bologna Via Gaudenzi, 9 1-40137 Bologna

Dr. Maria Tomasso Gajno Ospedale Infantile Regina Margherita Piazza Polonia 94 1-10100 Torino

Dr. Giancarlo Dal Pozzo Instituto di Radiologia Universita di Firenze I-Firenze

Dr. Massimo Galluci Department of Radiology Ospedale Collemaggio 1-67100 L'Aquila

Dr. Sergio Dalbuono Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40139 Bologna

Dr. Giovanni Giordana Clinica della Malattie Nervose dell'Universita Via U. Foscolo 7 1-400139 Bologna

Dr. Guiseppe De Rosa Via R. Falvo 10 1-80127 Napoli

Dr. Giovanni Giua Instituto Neurologico 11, Via Celoria 1:20133 Milano

Dr. Alberto Calabro Via Nevio t02/D 1-80122 Napoli

Dr. Pietro Dettori Instituto di Neuroradiologia Ospedale Civile di Vicenza 1-36100 Vicenza

Dr. Ferdinando Calzolari Via Ugo Bassi 22 1-44100 Ferrara

Prof. Raffaele Elefante Via Monte di Dio n. 66 1-80132 Napoli

Dr. Raffaetlo Canapicchi Via Cisanello 27/A 1-56010 Ghezzano Pisa

Dr. Giuliano Fabris Via Patrioti 1-33100 Colugna di Udine

Dr. Aristide Carella Neuroradiologia Universita Policlinico 1-70125 Bari

Dr. Leo Fagioli Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40139 Bologna

Pro~AmbrogioCecchini ClinicaNeuroiogica dell'Universita Via Paiestro 3 1-27100 Pavia

Dr. Francesco Federico Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40139 Bologna

Dr. Giorgio Grossi Neuroradiologia E. O. Galliera Via Mura Delle Cappuccine 14 1-16132 Genova Dr. Guido Guglielmi U.C.L.A. Medical Center Department of Radiology 10833 Le Conte Avenue Los Angeles (CA) 90024-1721 USA Dr. Giulio Guidetti Servizio di Neuroradiologia Dipartimento di Scienze Neurologiche-Universita di Roma "La Sapienza" 1-00185 Roma Dr. Pier Luigi Lanza Via Pasquale Rossi I26 1-87100 Cosenza

S 244 Dr. Antonio Lavaroni Servizio di Neuroradiologia Ospedale Civile 1-33100 Udine

Dr. Ugo Pasquini Servizio di Neuroradiologia Ospedale Generale Regionale 1-60100 Ancona

Prof. Marco Leonardi Servicio di Ne~oradiologia Ospedale Civile 1-33100 Udine

Prof. Angelo Passerini tnstituto Nazionale Neurologico "C. Besta" Via Celoria 11 1-20133 Milano

Dr, William Liboni Clinica Neurologica Universitaria 1-10100 Torino Dr. Manueta Manfredini Reparto di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40I 39 Bologna Dr. Anna Frederica Marliani Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr, Adriano Maschio Servizio di Neuroradiologia Ospedale Civile Maggiore 1-37126 Verona Dr. Francesco Matozzi Reparto di Neuroradiologia dell'Ospedale Bellaria Via Attura 3 1-40139 Bologna Dr. Francesco Menichelli Servizio di Neuroradiologia Ospedale Generale Regionale 1-60100 Ancona Dr. Francesco Morello Via dei Pritanei 18 1-89100 Reggio di Galabria Dr. Luca Moschini Servizio di Neuroradiologia Ospedale Riuniti 1-24100 Bergamo Dr. Ida Muras Neuroradiology ist Medical School C.T.O. Hospital Via le Colli Aminei, 21 1-80131 Napoli Dr. Giacomo Nuzzo Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40t39 Bologna Dr, Alberto Orlandini Neuroradiologia Ospedale Civile 1-25100 Brescia Dr, Achille Patmieri Ospedale "S. Leonardo" I-Salerno

Dr. Kurt Pardatscher Servizio di Neuroradiologia Ospedale Civile Via Giustiniani 5 1-35100 Padova Dr. Stefano Perini Servizio di Neuroradiologia Ospedale Civile Maggiore 1-37126 Verona Prof. Guiseppe Pero Instituto di Neurochirurgia Servizio di Neuroradiologia Ospedale Garibaldi I-Catania Dr. Vittore Pinna Instituto di Neuroradiologia Ospedale Civile di Vicenza 1-36100 Vicenza Dr. Sandra Pieralli Servizio di Neuroradiologia Ospedale San Raffaele Via Olgettina 60 1-20132 Milano Dr. Nello Quilici Servizio di Neuroradiologia Ospedali Riuniti Viale Alfieri 36 1-57100 Livorno Prof. Georgio Ramella Via G. Bruno 38-14 1-16146 Genova GE Dr. Claudio Righi Servizio di Neuroradiologia Ospedale San Raffaele I-Milano Dr. Marco L. Rosa Servizio di Neuroradiologia Ospedale San Martino V. de Bendetto XV 10 1-16132 Genova Prof. Giovanni Ruggiero Servizio di Neuroradiologia Ospedale Maggiore Via Altura 3 1-40139 Bologna Dr. Rosario Ruggiero Via Giotto 70 1-80128 Napoli

Dr. Luciano Sabattini Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Prof. Ugo Salvolini Servizio di Neuroradiologia Nuovo Ospedale Generale 1-60020 Torrette di Ancona Dr. Guiseppe Santoro Via S. Pietro 7 1-87044 Cerisano (Cosenza) Dr. Mario Savoiardo Department of Neuroradiology Instituto Nazionale Neurologico "C. Besta" Via Celoria 11 1-20233 Milano Dr. Giuseppe Scialfa Servizio di Neuroradiologia Ospedale Maggiore, Niguarda 1-20162 Milano Prof. Giuseppe Scotti Servizio di Neuroradiologia Ospedale San Raffaele Via Olgettina 60 1-20131 Milano Dr. Assunta Scuotto Neuroradiotogy 1st Medical School C.T,O. Hospital Via le Colli Aminei, 21 1-80131 Napoli Dr. Antronio Sicuro Clinica Neurologica Universitaria 1-10126 Torino Prof. Francesco Smaltino Instituto di Radiologica II, Nuovo Policlinico Via Pansini 5 1-80131 Napoli Dr. Alessandra Splendiani Department of Radiology Ospedale Collemaggio 1-67100 L'Aquila Dr. Liliana Strada Instituto Nazinale Neurologico "C. Besta" Via Celoria 1t 1-20133 Milano Dr, Donatella Tampieri Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr, Claudio Trevisan Servizio di Neuroradiologia Policlinico di Modena Via del Pozzo 71 I-Modena

S 245 Dr. Fabio Triulzi Servizio di Neuroradiologia Ospedale S. Raffaele Via Olvettina 60 1-20132 Milano

Prof. F. L. M. Peeters Academisch Medisch Centrum Afdeling Radiodiagnostiek Meibergdreef 9 NL-1105 AZ Amsterdam

Dr. Maria-Antonietta Vaghi Instituto Nazionale Neurologico "C. Besta" Via Celoria 11 1-20133 Milano

Prof. K. Penning Emmalaan 7 NL-9752 KR Haren

Dr. Consuelo Valentini Servizio di Neuroradiologia CTO 1-10126 Torino Dr. Vincenzo Valentino Docenti di Neuroradiologia Via Cadlolo 90 1-00100 Roma Dr. Anna Visciani Serviziodi Neuroradiologia Ospedate San Raffaele Via Olgettina 60 1-20132 Milano

Monaco Dr. Michel-Yves Mourou Service d'Imagerie Mediale (Scanner) Centre Hospitalier Princesse Grace Rue Pasteur MC-98000 Monaco

Netherlands Dr. Gareth Davies St, Lucas Ziekenhuis Afdeling Radiodiagnostiek J. Tooropstraat 164 NL-1061 AE Amsterdam Dr, R. G. M. de Slegte Majella Ziekenhuis Afdeling Radiodiagnostiek NW Hitversumseweg 20 NL-1406 TE Bussum Dr, R, E, M. Hekster Ziekenhuis Leyenburg Afedling Radiodiagnostiek Leyweg 275 NL-2545 CH den Haag Dr. Peter H. L. Kessing St. Laurentius Hospital MC Driessenstr. 6 NL-6043 CV Roermond Dr, J, L. Merx Institut voor Radiodiagnostik Sint Radboudziekenhuis Geert Grooteplein zuid 18 NL-6500 HB Nijmegen E. M,, Dr. W. J. Oberbeek Terborgsteeg 15 NL-9751 BN Haren

Dr. Rik L. Prevo Beethovenlaan 22 NL-7522 HJ Enschede Dr. Jan M. Rodermond Department of Neuroradiology Ziekenhuis de Weezenlanden Grott Weezenland 20 NL-8011 JW Zwolle Dr. Frans Ter Linden Diaconessenhuis Ds. Th. Fliednerstraat 1 NL-5631 BM Eindhoven Prof. Henk Thijssen Department of Neuroradiology Institute of Roentgenology St. Radbouziekenhuis Reinier Postlaan 4 NL-6525 GC Nijmegen Dr. T. G. Tjan St. Elisabeth Ziekenhuis Afdeling Radiodiagnostiek Jan van Beverwijckstraat 2A Prof. Jacob Valk NL-5017 JB Tilburg Academisch Ziekenhuis Vrije Universiteit PO Box 7057 NL-1007 MB Amsterdam Dr. H. H. van Woerden RK Ziekenhuis Van Swietenlaan 4 NL-9728 NZ Groningen Dr. G, J. Vielvoye Academisch Ziekenhuis Leiden Afedling Radiodiagnostiek Rijnsburgerweg 10 NL-2333 AA Leiden Dr. J. T. Wilmink Academisch Ziekenhuis Groningen Afdeling Neuroradiologie Oostersingel 59 NL-9713 Groningen

Norway Dr. Inge Marie Anke 9012 Regionsykehuset N-Tromsoe Dr. Jacob Soren Bakke Department of Neuroradiology National Hospital Rikshospitalet N-0027 Oslo, 1 Dr. Per Tobias Brodtkorb R6ntgen Department Drammen Sykehus N-3000 Drammen Dr. Gunnar Dugstad Department of Neuroradiology Ulleval Sykehus N-0027 Oslo 1 Dr, Reidar Dullerud Nevroradiologisk Avd, Ulleval Sykehus N-0407 Oslo 4 Dr. Petter Eldevik Nevroradiologisk Avdeling Ulleval Sykehus N-0407 Oslo 4 Dr. John K. Hald Rbntgenavd. Rikshospitalet University Hospital N-0027 Oslo 1 Dr, John Ludvig Larsen Department of Radiology Haukeland Hospital N-5021 Bergen Dr. Olaf Nicolal Pedersen Aust-Agder Sentralsykehus Rontgenavdelingen N-4800 Arendal Dr. Per Hjalmar Nakstad Nevroradiologisk Avd. Rikshospitalet N-0227 Oslo 1 Dr. Ingar O. Skalpe Neuroradiologisk Avdeling Rikshospitalet Pilestredet 32 N-0027 Oslo_l

Prof. B. G. Zeidses des Plantes Parkweg 9 A NL-2061 BM Bloemendaal

Dr. Ove Sortland R6ntgenavdeling Rikshospitalet Pilestredet 32 N-0027 Oslo 1

Dr. J. J. Zonjee Maasland Ziekenhuis Sittard Walramstaat 23 NL-6131 BK Sittard

Dr. Asbjorn Syvertsen R6ntgenavdeling Vesffold-Sentralsykehus N-3100 T6nsberg

S 246

Poland Dr. O. Billewicz Institut Radiologii Akademii Medycznej Kopernika 19 PL-31-501 Krakow Dr. Stanislav Bryc Department Radiology Radiology Medical Academy PL-20-081 Lublin Dr. Ryszard Golabek A. 1. Sobieskiego 1/9 PL-02-785 Warszawa Dr. Piotr Kozlowski Department of Neuroradiology Institute of Psychiatry and Neurology 1/9 Sobieskiego Str. PL-02-957 Warszawa Dr. Teresa Kryst Department of Neuroradiology Institute of Psychiatry and Neuroradiology 1/9 Sobieskiego Str. PL-02-957 Warszawa

Dr. Joaquim Cruz Sao Joao Servico Neuroradiologia P-Porto

Dr. Arturo Alonso-Garcia Neuroradiologia Hospital General de Asturias E-Oviedo

Dr. Antonieta Galdino Dias Servico de Neuro-Radiologia Hospitals da Universidade de Coimbra Praceta Prof. Mota Pinto P-3049 Coimbra Codex

Dr. Tomas Amor Azpeitia Servicio de Radiologia Residencias Sanitaria Ortiz de Zarate C/Jose Achotegui E-Vitoria (Alava)

Dr. Julia Duarte Hospital de Egas Moniz Servico de Neuroradiologia Rua da Junqueira 126 P- 1300 Lisboa Dr. Pedro Evangelista Hospital de Egas Moniz Servico de Neuroradiologia Rua da Junqueira 126 P-1300 Lisboa Dr. Augusto Goulao Servico de Neuroradiotogia Hospital de Egas Moniz Rua da Junqueira, 126 P-1600 Lisboa

Dr. J.-B. Lipska-Wygodzka ul. Piotrkowska 182 PL-90-368 Lodz

Dr. Jorge Guedes Campos Dept. Radiologia-Neuroradiologia Hospital Sta. Maria Av. Egas Moniz P- 1600 Lisboa

Dr. Karimierz Niezabitowski Clinic of the Pomeranian Academy Neurochirurgia Unit Lubelskej 1 PL-Szczecin

Dr. Jaime Cruz Mauricio Servico de Neuro-Radiologia Hospital de Egas Moniz Rua da Junqueira, 126 P-1600 Lisboa

Dr. Jorge Trzebicki Sercice de Neuroradiologie Institut Psychoneurologii PL-Varsovie

Dr. Eduardo Medina Hospital de Egas Moniz Servico de Neuroradiologia Rua da Junqueira 126 P-1300 Lisboa

Dr. Jerzy Walsecki Neuroradiological Department Neurosurgical Clinic Polish Academy of Sciences 16 Barska Str. PL-02325 Warszawa Dr. Jerzy Woznia Insfitut of Radiology Staszica 16 PL-20-081 Lublin Prof. Jerzy Zajgner Tuwima 84/11 PL-90-026 Lodz

Dr. Paulo A. Mendo Servico de Neuro-Radiologia Hospital de Santo-Antonio P-4100 Porto Dr. Constanca Ribeiro Hospital de Egas Moniz Servico de Neuroradiologia Rua da Junqueira 126 P- 1300 Lisboa Dr. Fernandes Sousa Hospital Universidade Coimbra Departamento Neuroradiologia P-Coimbra

Portugal Spain Dr. Fernando Manuel Costa Reis S. Neuroradiologia Hospital de Santo Antonio dos Capuchos Alameda de Santo Antonio dos Capuchos P-1100 Lisboa

Dr. J. M. Alfonso y Alfonso Neuroradiologia Clinica La Paz Avda. Generalissimo 177 E-Madrid 34

Dr. Manuel de Juan Neuroradiology Section Hospital Sant Pan S. Antoni M. Claret 167 E-08025 Barcelona Dr. Luis Escudero San Telmo 3 E-28016 Madrid Dr. Hernan Luis Espinet Elizalde Secci6n Neuroradiologia C. Sanitaria Principes des Espafia E-Bellevitje (Barcelona) Dr. Victor Queimadelos Garcia Fundawan Imenez Diaz Avd. Reyes Catolizos, 2 E-28010 Madrid Dr. Eduardo Garcia-Cervignon c/Fontan n ° 5,1 ° E-La Coruna Dr. Esteve Guardia Neuroradiology Section Hospital Sant Pan S. Antoni M. Claret 167 E-08025 Barcelona Dr. Leopoldo Guimaraens Martinez Service of Neuroangiography Clinica Quiron Paseo Mariano Renovales s/u E-50006 Zaragosa Dr. Bernardo Ibarra Servicio Neuroradiologia Ciudad Sanitaria Seguridad Soc. Universidad Autonoma Valle Hebron, s/n E-Barcelona- 16 Dr. Juan Viano Lopez Gaztambide 64, 4 D 28015 Madrid Dr. Jose Fernandez Lopez-Lara Londre 54 -3a 2a "A" E-Barcelona - 36 Dr. Angel Martinez Muniz "Hospital Juan Canalejo" Las Jubias 84 E-15004 La Coruna

S 247 Prof. Dr. Jose M. Mercader Hospital Clinic I Provincial Universidad de Barcelona Seccion de Neuroradiologia Villaroel 170 E-08036 Barcelona Dr. Jose Luis Montfort Liabines Paris, 122 --6 ° 2a E-Barcelona - 36 Dr. Luis Nombela Servicio de Neuroradiologia Clinica Puerte de Hierro C/San Martin de Porres 4 E-28035 Madrid Dr. Ignacio Pascual-Castroviejo C/Orense 14-10° E E-28020 Madrid Dr. Emilio Lucas Pinilla Apartado Correos 18 E-Burjasot (Valencia) Dr. Mercedes Perez Romero Ona I83 E-28050 Madrid Dr. Luis C. Pons Europa 15, 4° 3a E-08028 Barcelona Dr. Fernando Quintana Servicio de Neuroradiologia Hospital de Santander E-Santander Dr. Francisco-Javier Romero Servicio Neuroradiologia Ciudad Sanitaria S. Social P. Valle Hebrdn s/n E-08016 Barcelona Prof. Mariano Rovira Molist Servicio Neuroradiologia Ciudad Sanitaria Serguridad Soc. E Valle Hebr6n, s/n E-Barcelona- 16 Prof. Jordi Ruscalleda Neuroradiology Section Hospital Sant Pau S. Antoni M. Claret 167 E-08025 Barcelona Dr. Ramon Serrano Servicio de Radiodiagnostico Hospital de la Seguridad Social Chagorrichu E-Vitoria Prof. Juan Sole-Lienas 40 Horacio E-08022 Barcelona Dr. Manuel Subirana Instituto Neurologico Municipal E-Barcelona

Dr. Dario Taboada c/Socias 47 E-07010 Palma de Mallorca Dr. Oriot Torrent Badia Ganduxer 55 1° la E-Barcelona Dr. Enrique Trnjillo Ferre Neuroradiologia Hospital General y Clinico E-Ofra Tenerife (Canarias) Dr. Jorge Vazquez Rebollar Seccion de Neuroradiologia Ciudad Sanitaria Juan Canatejo E-La Coruna Dr. Jose Luis Zubieta Zarraga Unidad de Neuroradiologia Clinica Universitaria Universidad de Navarra Apartado 192 E-3 t080 Pamplona

Sweden

Dr. Mgrten Annertz Department of Diagn. Radiology University Hospital S-22185 Lund Dr. Gustaf Bergstrand Department of Radiology Vgllingby L~ikarhus Indalsbacken 17 S- 162 Viillingby Prof. Kjell Bergstr6m Department of Diagnostic Radiology University Hospital S-75185 Uppsala Dr. Ulf Bergvall Department of Diagnostic Radiol. Huddinge University Hospital S-14186 Huddinge Dr. Brigitte Berthelsen Dept. of Neuroradiology Sahlgren's Hospital S-41345 Gothenburg Dr. Sten Cronqvist St~ingbackagr~inden 14 Barseb~ckshamn S-24021 L6ddek6pinge Dr. Sven Ekholm Department of Diagnostic Radiology Sahlgren Hospital University of Gothenburg S-41345 Gothenburg Prof. Kaj Ericson Department of Neuroradiology Karolinska Hospital S-10401 Stockholm

Dr. Olof Flodmark Department of Neuroradiology Karolinska Hospital S-10401 Stockholm Dr. Dan Greitz Neuroradiologia Karolinska Sjukhuset S-t0401 Stockholm Prof. em.Torgny Greitz Neuroradiologiska AVD Karolinska Sjukhuset S-10401 Stockholm Dr. Arne Grepe R6ntgenavdelingen Roslagstulls Sjukhuset Box 5901 S-11489 Stockholm Prof. Tomas Hindmarsch Department of Neuroradiology Karolinska Sjukhuset S- 10401 Stockholm 60 Dr. Stig Holt~.s Department of Diagnostic Radiology University Hospital S-22185 Lund Dr. Elna-Marie Larsson Department of Diagnostic Radiology University Hospital S-22185 Lund Prof. Bengt Liliequist R6ntgenavdelning Lasarettet S-90185 Umea Dr. Anders Lillja Dpt. of Diagnostic Radiology Academic Hospital S-750 Uppsala Prof. Melker Lindqvist Sollidenv. 5 S-18365 T~iby, Stockholm Dr. Lars L6wengren Hospital C S K S-291 85 Kristianst Dr. Olle Marions R6ntgenavd. S6dersjukhuset Box 38100 S-t00 64 Stockholm Dr. Mikael Mosskin Department of Neuroradiology Karolinska Hospital S-1040I Stockholm Dr. Ulf Mostr6m Dpt. of Diagnostic Radiology Academic Hospital S-75185 Uppsala

S 248 Dr. Claes Radberg R6ntgendiagnostiska Kliniken 1 Regionsjukhuset S-58185 Link6ping

Dr. Werner Wichmann Neuroradiologie Universiffttsspital CH-8091 Zt~rich

Dr. Timothy C. S. Cox Neuroradiology Guy's Hospital GB-London, SE 19 RT

Dr. Sture Stattin R6ntgendiagnostiska Kliniken 11 Sahlgrendka Sjukjuset S-41345 G6teborg

PD. Dr. Urs Wiggli von Loewenich R6ntgeninstitut Aechenvorstadt 57a CH-4052 Basel

Dr. Roberts Simon Dossetor Hurstwood Park Neurological Centre GB-Haywards Heath West Sussex

Turkey

Dr. Keith Hall Regional Neurological Center Newcastle General Hospital GB-Newcastle-Upon Tyne

Prof. Pal Svendsen Department of Radiology Sahlgren Hospital S-41345 G6teborg

Switzerland Prof. Ryszard Chrzanowski Centre Hospitalier Universitaire Vaudois Radiodiagnostic Department CH-1011 Lausanne Pro~PeterHuber NeuroradiologischeAbteilung Inselspital CH-3010 Bern Dr. Philippe Maeder Service de Radiologie Centre Hospitalier Universitaire Vaudois Rue du Bugnon CH-1011 Lausanne Dr. Marcelle Megret Service de Neuroradiologie H6pital Cantonal CH-1206 Geneve

Prof. Cahit Babuna Neurologic Department Istanbul Medical Faculty Istanbul University Capa TR-Istanbul Dr. Sara Bahar Istanbul Medical Faculty Department of Neurology Capa TR-Istanbul Prof. Gencay Gfirsoy Topagaci, Poyracik sok. Nisantasi n° 1 D:6 TR-Istanbul Prof. Reha Tolun Neuroradiologic Department Istanbul Medical Faculty Istanbul University Capa TR-Istanbul

United Kingdom Dr. AngelMironov Neuroradiologie Kantonsspitat CH-5001Aarau Dr. Roland Oberson Centre d'Imagerie Diagnostique Grand-Chene 8 BIS CH- 1003 Lausanne Dr. Ernst-Wilhelm Radfi Neurologische Abteilung Kantonsspital Basel CH-4031 Basel Dr. Roberto Rivoir Neuroradiologische Abteilung Inselspital CH-3010 Bern Priv.-Doz. Dr. Othmar Schubiger Klinik im Park Seestraf3e 220 CH-8027 Zfirich Prof. Anton Valavanis Abt. f. Neuroradiologie Universit/itsspital Frauenklinikstrage 10 CH-8091 Zt~rich

Dr. James Ambrose Atkinson Morley Hospital Copse Hill Wimbledon GB-London S.W. 20 Dr. Philip Anstow Department of Neuroradiology The Radcliffe Infirmary Woodstock Road GB-Oxford OX2 6HE Dr. Richard Bartlett X-ray Department Hull Royal Infirmary Anlaby Rd. GB-HuU, HU 3252 Prof. George du Boulay Old Manor House Brington GB-Huntington Cambs., PE 18 OPX Dr. Juliet Anne Britton Neuroscience Centre Atkinson Morley's Hospital Copse Hill Wimbledon GB-London SW 20 ONJ

Dr. Desmond T. Hawkins Greyfairs Church Green Little Wilbraham GB-Cambridge CBI 5 LE Dr. Matthias Cornelius Hickey Cork Regional Hospital Innishannon Ireland Dr. Richard D. Hoare The Cottage Hollesley Farm Norman's Road GB-Smalfield, Surrey RH 6 9JJ Dr. Ian M. Holland Department of Radiology University Hospital Queens Medical Centre GB-Nottingham NG7 2UH Dr. Till Hunter The National Hospital for Neurology and Neurosurgery Queen Square GB-London WI Prof. Ian Isherwood Department of Diagnostic Radiology, Medical School University of Manchester GB-Manchester M 13 9PT Dr. Brian Ernest Kendall Lysholm Department of Radiology National Hospital Queen Square GB-London WC 1N 3BG Dr. Derek Kingsley National Hospital for Nervous Diseases GB-London WC 1N 3BG Dr. John T. Lamb The General Infirmary at Leeds Great George Street GB-Leeds LS 1 3EX Dr. Anthony Leung Radiology Department Mount Vernon Hospital GB-Middleessex, UB 10 8EB

S 249 Dr. Victor Mc Altister Dpt. of Neuroradiology Newcastle General Hospital Westgate Road GB-Newcastle Upon Tyne NE4 6BE Dr. Andrew J, Molyneux Department of Neuroradiology The Radcliffe Infirmary Woodstock Road GB-Oxford OX2 6HE Prof. Ivan Moseley Department of Radiology National Hospital Queen Square GB-London WC IN 3BG Dr. Winton McNab Dundee Royal Infirmary GB-Dundee Scotland DDI 9 ND Dr. Thomas Powell Neuroradiology Royal Hallamshire Hospital Glossop Road GB-Sheffield S 10 2JF Dr. Philip Sheldon Dpt. of Neuroradiology Radcliffe Infirmary GB-Oxford Dr. Gordon Thomson Neuroradiology Frenchay Hospital Bristol Royal Infirmary GB-Bristol Dr. Ian W,Turnbull X-Ray Department North Manchester General Hospital Crumpsall GB-Manchester M 8 6RB Lancs Prof. Brian Worthington Department of Radiology Queen's Medical Centre Clifton Boulevard GB-Nottingham NG7 2UH Dr. Ian G. Wylie Department of Neuroradiology The London Hospital GB-London E 11 BB

Yugoslavia Dr. Martin Cerk Inst. Za Rentgenologijo KBC Zaloska 7 YU-61000 Ljubljana Dr. Vilim-Alan Kamier Andrijeviceva 7 YU-41000 Zagreb

Prof. Marijan Lovrencic Ktin. Bolnica "Dr. M. Stojanovic" Zavod za Radiologiju Vinogradska 29 YU-41000 Zagreb

Australia

Dr. Nikola Mitrovic Institute of Oncology and Radiology Pasterova 14 YU-1100 Beograd

Dr. Makhan S. Khangure 26, Circe Circle Aus-Dalkeith 6009

Prof. Josip Stojanovi6 Central Institute for Tumors and all, Dis. Ilica 197 YU-41000 Zagreb-YU Dr. Markovic Zeljko KBC Kragujevac Zavod Za Radiologijn U1. Zmaj Jovina 30 YU-3400 Kragujevac

Associate Members Algeria Dr. Rachid Allal 7, rue M'Rah Djamal DZ-Tlemcen Prof. A. Zerhouni HopitaI AIi Ait Idir Service de Radiologie Boulevard A. Hadad DZ-Algiers

Arabia Dr. Mohamed Rudwan IBN Sina Hospital Radiology Department P.O. Box Nr, 25427 Kuwait 13115 Arabia Dr. Simeon Simeonov Department of Radiology IBN. Sina Spec. Surg. Hospital P.O. Box 25427, Zip Code 13115 Kuwait City, State of Kuwait Arabia

Argentina Dr. A. Casasco Sarmiento 85 1660 San Martin RA-Buenos Aires

Dr. Lesley Cala P.O. Box 105 Cottesloe Western Australia 6011

Dr. Yoi-Sun Soo Repatriation General Hospital X-Ray Department Hospital Road AUS-Concord/NSW 3139

Austria Univ.-Doz. Dr. Franz Aichner Universitgt Innsbruck Anichstrage 35 A-6020 Innsbruck Dr. Wolfgang Anzb6ck KH Rudolfstiftung-ZRI Jochgasse 25 A-1030 Wien Univ.-Doz. Dr. H. Binder Neurologische Universitgtsklinik Lazarettgasse 14 A-1090 Wien Dr. Peter Dal Bianco Neuroradiologische Abteilung Neurol. u. psych. Univ.-Klinik Lazarettgasse 14 A-1909 Wien Dr. Stephan Felber MRI-Institut Anichstrage 35 A-6020 Innsbruck Dr. Karl Heimberger Abteilung ftir Neuroradiologie Neurologische Klinik der Universitgt Wien Lazarettgasse 14 A-1090 Wien

Belgium Prof. Richard Gonsette 76, Boulevard St. Michel B-1040 Bruxelles Dr. Marc Rakofsky H6pital Universitaire Brugmann Place A. Van Gehuchten 4 B- 1020 BruxeUes Anne Rousseau-Jadoul Residence du Parc 57, Rue Courtejoie B~P. no. 4, 3 ieme &age B-5300 Ciney

S 250 Bolivia

Dr. Davita Jorge Gonzales Casilla no. 3415 La Paz Bolivien

Dr. Josef Vymazal Department of Neurology Postgraduate Medical School Videnska 800 CS-14059 Praha 4

Ecuador Brazil

Dr, Carlos Fonseca Prestes Rue Conselheiro Dantas t05 BR-800000 Curitiba - Parana Dr, Antonio Tomaz Rezende Servicio de Radiodiagnostico Neuro-Radiologia Hospital de Ipanema Caixa Postal 70067 BR-22422 Rio de Janeiro, RJ

Canada

Dr. D.C. Amstrong The Hospital for Sick Children 555 University Avenue CDN-Toronto, Ontario M 5 G IX8 Dr. Sylvester Chuang Hospital for Sick Children 55, University Avenue CDN-Toronto, Ont. 1156 IX8 ProL Derek C. Harwood-Nash Department of Radiology The Hospital for Sick Children 555 University Avenue CDN-Toronto, Ontario M5 G IX 8

Chile

Prof. Mario Corrales Radiologia Hospital Universidad Catolica Marcoleta 347 RCH-Santiago

Dr. Gonzalo A. Duenas-Mera Instituto Radiologico, Cenmep E. Espejo Hospital Veintimilla 1259 EC-Quito

Prof. Neum~rker Klinik u. Poliklinik f. Neurologie u. Psychiatrie d. Bereiches Medizin (Charit6) Schumannstr. 20/21 D-1040 Berlin

Egypt

Dr. Nikolaus Obletter Magnetresonanztomographie Leonhard-Paminger-StraBe 1 D-8390 Passau

Prof. Mohamed E1 Deeb Department of Radiology School of Medicine Alexandria University ET-Alexandria

Priv.-Doz. Dr. Winfried Roos Neurolog, Klinik Krankenanstalten des Landeskreises Posilipostrage 49 D-7140 Ludwigsburg

Federal Republic of Germany Dr. Otto Eschbach Urbacher Weg 31 D-5000 K61n 90 Dr. Claude Faubert Abteilung ftir Radiodiagnostik der Radiologischen Klinik Universit~tt des Saarlandes Med. Fakult~it D-6650 Homburg-Saar Prof. Horst Herrschaft Ltd. Arzt der Neurolog. Klinik Nieders. Landeskrankenhaus Wienebiittelerweg 1 D-2120 Ltineburg Prof. F. Heuck Herrmann-Kurz-Strat3e 5 D-7000 Stuttgart 1

CSFR

Dr. Johannes Iisuka Karl-Justi-Str. 20 D-5300 Bonn 1

Dr. Pavol Kalina Neurological Clinic Postgraduate School of Medicine Smidkeho 6 CS-82606 Bratislava

Prof. Stephan Kunze Direktor der Neurochirurg. Klinik Klinikum der Universitgt Im Neuenheimer Feld 400 D-6900 Heidelberg 1

Dr. Antonin Krajina Faculty of Medicine Charles University Department of Radiology CS-50036 Hradec Kralove

Prof. W.R. Lanksch Abteilung fiir Neurochh-urgie Universit~itsktinikum Rudolf Virchow Standort Wedding Augustenburger Platz 7 D-1000 Berlin 65

Dr, Renee Schickerova Department of Neurology Postgraduate Medical School CS- 14059 Praha 4

Prof. Eberhard L6hr R6ntgendiagn. Zentralinstitut Klinikum der Universit~it Essen (GHS) Hufetandstrage 55 D-4300 Essen I

Dr. Hans-Otto Lincke Neurologische Klinik der St~idtischen Kliniken Beurhausstrage 40 D-4600 Dortmund 1

Prof. Kurt Schiirmann Neurochirurgische Klinik und Poliklinik Johannes Gutenberg-Universitfit Langenbeckstrage 1 D-6500 Mainz t Dr. Friedrich Strian Neurologische Poliklinik Max-Planck-Institut f. Psychiatrie Kraepelinstrage 10 D-8000 Mi~nchen 40 Dr. Z. Taneri Hans-Bockler-StraBe 20 D-4100 Duisburg

France Dr. A. Abanou Service de Neuroradiologie H6pital des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. AI. Arzimanoglou Neurologist-Child Neurologist H6pital de la Salpetri&e Ctinique Neurologique 47, Bld. de l'H6pital 750 13 Paris Dr. Jean-Marie Andr6 Clinique Medicale B Centre Hospitalier et Universitaire F-54500 Nancy-Brabois Dr. Monique Boukobza Departement de Neuroradiologie H6pital de la Piti6 83, Boulevard de l'H6pital t?-75634 Paris Dr. Andr6 Charbit 24, Rue de la Faisanderie F-75116 Paris

S 251 Dr. Philippe Cotty Service de Neuroradiologie Centre Hospitalier Regional Bretonneau F-37000 Tours

Dr. Henry Nataf Service de Neuroradiologie H6pital de la Piti6 83, Boulevard de L'Hbpital F-75651 Paris Cedex 13

Dr. Michel Dumas Service de Neuroradiologie Centre Hospitalier Universitaire F-87000 Limoges

Dr. Michel Royon Radiodiagnostic Centre Hospitalier 14, Avenue des Broussailles F-06401 Cannes

Dr. Jean-Luc Dutreix Service de Neuroradiologie Centre Hospitalier Regional 2, Boulevard Tonnelle F-37044 Tours Cedex Dr. Jacques Faure "Les Tamaris" Chemin du Crouton F-83500 Toulon Dr. Nicolas Fayed Miguel Service de Neuroradiologie Centre National d'Ophthalmologie des Quinze-Vingts 28, Rue der Charenton F-75571 Paris Cedex 12 Dr. LiIiana Feldman 8, Rue Dagomo F-75012 Paris Dr. Pierrick Forlodou 22, Rue du Calvaire F-29000 Quimper Dr. Demis Gemse de Beaufort Service de Neuroradiologie Hfpital Pellegrin-Tripode F-33076 Bordeaux Cedex

Dr. Jean-Louis Sautreaux Service de Neurochirurgie Hfpital General 3, Rue dn Faubourg Raines F-21000 Dijon Prof. Andr~ Thierry Service de Neurochirurgie H6pital General 3, Rue du Faubourg Raines F-21033 Dijon Cedex

Dr. Atef Majdalani Service de Neuroradiologie Hfpital des Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex 12 Dr. J. Mani Department de Neuroradiologie C.H.U. de Caen Avenue de la C6te de Nacre F-14033 Caen Dr. Kathlyn Marsot-Dupoch H6pital St. Antoine t84, Rue du Fb. St. Antoine F-75012 Paris Dr. Claude Michel Service de Neuroradiologie H6pital de la Piti~ 83, Boulevard de L'H6pital F-75651 Cedex 13

Dr. R. V. Phadke Sanjay GandhiPost-Graduate Institute of Medical Sciences P.O. Box NO. 375 Raebareli Road IND-Lucknow (U.P.)

Israel Dr. Irith Reider-Groswasser Department of Radiology Section of Neuroradiology Elias Sourasky Medical Center Ichilov Hospital IL-64239 Tel Aviv

Dr. Charles Thomas Service de Neurologie H6pital Bel Air Rue Friscaty F-57100 Thionville

Dr. Rina Tadmor Neuroradiologist Chaim Sheba Medical Center I1-Tel-Hashomer

Dr. Etisabeth Vitte Laboratoire d'Anatomie H6pital Pitid-Salpetri~re 105, Boulevard de l'H6pital F-75634 Paris Cedex 13

Italy

Dr. Abderrezak Zouaoui 271, Rue de Belleville 1=-75019 Paris

Greece Dr. Roseline Kulas Service de Neuroradiologie Centre National d'Ophthalmologie de Quinze-Vingts 28, Rue de Charenton F-75571 Paris Cedex

Dr. Viral Viral C. Shah M. R. I. Center Breach Candy Hospital and Research Center 60, B:: Desai Road IND~400026 Bombay

Dr. Athanase Gouliamos Areteion Hospital Department of Radiology University of Athens 76, Vas. Sophias Avenue GR-115-28 Athen Dr. Christos Papayannis Synchronous Medical Diagnosis S.A. GR-54646 Thessaloniki

Dr. Bruno Bernardi Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr. Antonella Bacci Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr. Agostino Boatto Via Angelini 73 1-60100 Ancona Dr. Massimo Giuliano Bonetti Corso Trieste 211 1-00198 Roma Dr. Alessandro Bozzao Department of Radiology Ospedale Collemaggio 1-67100 L'Aquila

Hungary Dr. Istvan Nagy Tovirag u. 10 x/43 H-1108 Budapest

Dr. Gianfranco Catalano Servizio di Neuroradiologia Ospedali Riunti G. Malecrino e E Bianchi Via Malecrino 1-89100 Reggio di Calabria

India Dr. D.S. Dadhich Department of Neuroradiology The Bombay Hospital M.R.C. Building, 2nd floor 12, Marine Lines IND-Bombay 20

Dr. Antonio Gangemi Servizio Autonomo di Neuroradiologia-Ospedali Riuniti G. Melacrino e E Bianchi Via Malecrino 1-89100 Reggio di Calabria

S 252 Dr. Marcello Longo Universita degli Studi di Messina Policlinico G. Martino-Gazzi Instituto di Radiologia 1-98100 Messina Dr. Maria-Cristina Malaguti Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr. Guiseppe Marandola Via Orazio 149 1-80100 Napoli Dr. Giampiere Marconi Via Montebuoni 155 1-50029 Tavarnuzze Firenze Dr, Guiseppe Morello Ospedale Civile Neuroradiologia 1-74100 Taranto Dr, Renata Ricci Servizio di Neuroradiologia Ospedale Bellaria Via Altura 3 1-40139 Bologna Dr. Armando Tartaro Instituto di Scienze Radiologiche Ospedale SS. Annunziata Via Valignani 1-66100 Chieti

Netherlands Prof. B. J. J. Ansink Sint Lucas Ziekenhuis Afd: Neurologie J. Tooropstraat 1264 NL-1061 AE Amsterdam Drs. E C. Crez6e Bovenij Ziekenhuis Afdeling Radiodiagnostiek Statenjachtstraat 1 NL-1034 CS Amsterdam Dr. R. de Raad Ziekenhuis de Weezenlanden Afdeling radiodiagnostiek Groot Wezenland 20 NL-8011 JW Zwolle Dr. J. Lakke Academisch Ziekenhuis Groningen Afdeling Neurologie Oostersingel 59 NL-9713 EZ Groningen Dr. B. Matriacali Slotervaartriekenhuis Afd: Neurochirurgie Louwesweg 6 NL-1066 EC Amsterdam Dr. M.L. van de Graaff Academisch Ziekenhuis Vrije Universiteit Afdeling Radiodiagnostiek Postbus 7057 NL-1007 MB Amsterdam

Japan Dr. Mutsumasa Takahashi Department of Radiology Kumamoto Univ, School of Med. I-t-I Honjo Kumamoto

Dr. L.M. Vencken Academisch Zkh. Groningen Afdeling Radiodiagnostiek Oostersingel 59 NL-9713 EZ Groningen

Poland

Dr. Antonio Carvajal Diaz Calle Congost 30-32 at. 2° E-08024-Barcelona Dr. Nicolas Fayed Miguel Service of Neuroradiology Clinica Quiron Paseo Mariano Renovales s/n E-50006 Zaragoza Dr. Luis Lopez-Ibor Hospital Provincial de Conxo E-Santiago de Compostela (Corufia) Spanien Dr. Manuel Trujillo Peco Servicio de Neuroradiologia Centro Medico "Ramon y Cajal" E-Madrid Dr. Martin Zauner Jakubik Villaroel 20%211, 50 E-08036 Barcelona

Sudan Dr. Abdel Rahman Mohamed Ellidir P.O. Box 888 Kahrtoum Sudan

Sweden Dr. Marianne Birch-Iensen R6ntgen, M.A.S. Malm6 General Hospital S-21401 Maim6

Syria Dr. Joseph Kardouss Immeuble Kardouss 30, Boulevard Alep Damas Syrien

Maroc Dr. Njat Bensouda Centre Hospitalier Universitaire B,P. 40-58 Ma-Rabat

Dr. Bozena Goraj Department of Diagnostic Imaging/Copernicus Hospital Medical Academy Lodz Gagarina 4 PL-93-530 Lodz

Mexico

Taiwan Dr. Robert Kwok Radiologic Clinic 300 Orchard Road 05-09 The Promenade 0923 Singapore

South Africa Dr. Rene Jaspeado Unicornio N ° 167 Col. Prado Churubusco C. P. 04230 MEX-Delegacion Coyoacan Dr. Marco Zenteno instituto Nacional de Neurologia Insnrgentes Sur 3877 Mex-Tlalpan 22 D. E

Prof. Leonard Charles Handler Neuroradiology Department Groote Schuur Hoispital ZA-Cape Town 7925

Dr. Chart-Chin Lee Tri-Services Hospital 2 F, 45 Alley 5 Lane 626 Ding-Chow Rod. Taipei Taiwan, R. O. C.

Spain Tunesia Dr. Salvador BarluengaVilajuana JefeDepartamentoRadiologia MntuadeSeguras E-Tarrasa

Prof. Radhi Hamza Service de Radiologie H6pital Charles Nicolle TN-Tunis

S 253 Dr. Slaheddine Touibi Service de Radiologie Centre de Neurologie Facult~ de Tunis TN-Tunis

Prof. Dieter R. Enzmann Department of Diagnostic Radiology & Nuclear Medicine Stanford University School of Medicine USA-Stanford, California 94305

Turkey

Prof. Mokhtar Gado Neuroradiology Section Mallinckrodt Inst. of Radiology Washington Univ. School of Medicine 510 S. Kingshighway USA-St. Louis, Missouri 63110

Dr. Halit Atila Idrisoglu Department of Neurology Neuroradiology Instanbul Univ.-CapaTR-34390 Istanbul

United Kingdom Dr. A.Abd E1-Salam Abd E1-Aziz National Hospital for Nervous Diseases Queen Square GB-London WCIN 3BG Dr. Philippe Demaerel Lysholm Radiological Department The National Hospital Queen Square GB-London WC1N 3BG Dr. Hesham Safar-Aly The National Hospital for Nervous Diseases Queen Square GB-London WCIN 3 GB

Uruguay Prof.NestorAzambuja Hospital de Clinicas Piso 2 U-Montevideo

USA Dr. Willam Otto Bank 109, Wimbledon Way USA-San Rafael, California 94901 Prof. Larissa Bilaniuk Department of Radiology Neuroradiology Univers. of Pennsylvania Hospital 34, Spruce Street USA-Philadelphia, 19104 Pennsylvania Dr. Nicole-E Bolender 8616 NE 23rd Place USA-Bellevue, WA 98004 Dr. Giovanni Di Chiro 5719 Kingswood Ct. USA-Bethesda, MD 20014 Dr. Gerard Debrun Interventional Neuroradiology Neuroradiology Section The John Hopkins Hospital USA-Baltimore, MD 21205

Prof. Anton N, Hasso Section of Neuroradiology Loma Linda University USA-Loma Linda, California 92354 Prof. Michael S. Huckman Neuroradiology Rush-Presbyterian St. Luke's Medical Center 1753 West Congress Parkway USA-Chicago, Illinois 60612

Dr. Imre Weitzner 27, Bretton Rd. USA-Scarsdale, N.Y. 10583 Prof. Gertraud Wollschlaeger Wayne State Univ. School of Medicine 5885 Winglake Road USA-Birmingham, Michigan 48010 Prof. S. Wolpert Department of Neuroradiology New England Medical Center Hospital 171, Harrison Avenue USA-Boston, Massachusetts 2041 Prof. Robert Zimmerman Department of Radiology Neuroradiology University Pennsylvania Hospital 34 Spruce Street USA-Philadelphia, Pennsylvania 19104

Yugoslavia Dr. J. Randy Jinkins Director of Neuroradiotogy Department of Radiology The University of Texas Health Science Center 7703 F. Curl Drive USA-San Antonio, Texas 78284 Dr. George Krol Memorial Hospital 1275 York Avenue Apt. 2100 USA-New York, N.Y. 10021 Dr. Michel Mawad 6434 Auden USA-Houston, Texas 77005 Prof. Thomas P. Naidich Department of Radiology Baptist Hospital 8900 North Kendall Drive USA-Miami, Florida 33176-2197 Prof. Thomas H. Newton Department of Radiology University of California USA-San Francisco, CA 94143 Dr. Daniel A. Ruefenacht West 2 - Department of Radiology Mayo Clinic 200 First St., S. W. USA-Rochester, MN 55905 Dr. Paul Pevsner 2112ESt. NW. SuRe #802 USA-20037WashingtonD.C. Prof. Juan M. Taveras Department of Radiology Massachusetts General Hospital USA-Boston, Massachusetts 02114

Prof. Dr. Xhemail Bajraktari Medical Faculty Department of Radiology YU-38000 Prishtina Dr. Nada Besenski Clinical Hospital "Rebro" Kispaticeva 12 YU-41000 Zagreb Dr. Aleksandar Ivanov Radioloski Institut U1. Vodnjanska 17 YU-91000 Skopje Dr. Anda Jasovic Vladimira Tomanovica 5 YU-11000 Beograd Dr. Pero Jurkovic Gen. Hosp. "Dr. J. Kajfe~, Radiology Department P. Miskine 64 YU-41000 Zagreb Dr. Predrag Petrovic Clinic of Neurosurgery MRI Center Visegradska 26 YU-11000 Beograd Dr. Miodrag Vrcakovski Medicinski Fakultet Radioloski Institut YU-91000 Skopje Dr. Milovan Vujicic Military Hospital Department of Radiology Crnotravska YU-11000 Beograd

S 254

World Federation of Interventional and Therapeutic Neuroradiology Dr. H. Trevor ApSimon Neuroradiology Royal Perth Hospital GPO Box X2213 Perth Australia 6001

Dr. Vicenzo Branca Neuroradiologia Ospedale Niguarda Piazza Ospedale Maggiore, No, 3 Milano Italy 30100

Dr. Joseph M. Eskridge Radiology, Rm. SB-05 University of Washington Hospital 1959 NE Pacific St. Seattle WA USA 98195

Dr. Aldo Benati Neuroradiologia Ospedale Maggiore Piazzale Stefani Verona Italy 37126

Dr. Michael F. Brothers Radiology Duke University Box 3808 Durham NC USA 27710

Dr. Richard A. Ftom Southwest Neuroimaging Ltd. P.O. Box 7458 Phoenix AZ USA 85011-7458

Dr. Edoardo Boccardi Neuroradiologie Ospedale Niguarda Ca'Granda Milano Italy 20159

Dr. Alfredo E. Casasco Radiologia Intervencionista Bilinghurst 2039 PBA 1425 Buenos Aires Argentina 743

Dr. Friedhelm Brassel Neuroradiologie Medizinische Hochschule Hannover Konstanty-Gutschow-Str. 8 Hannover 61 Germany 3000 Dr. Patricia Burrows Radiology Hospital for Sick Children 555 University Ave. Toronto Ont. Canada M5G 1XB Dr. Jacques Chiras Neuroradiology H6pital de la Salpetriere 47 Rue de l'H6pital Paris France 75013 Dr. Carlo Cimino Neuroradiology Instituto Neurologico "C. Besta" Via Celoria 11 Milano Italy 20133

Dr. In Sup Choi Radiology NYU Medical Center 560 First Ave. New York NY USA 10016 Dr. Timothy C. Cox The Neurosurgical Unit The Maudsley Hospital Denmark Hill London UK SE5 8A2 Dr. Kenneth R. Davis Radiology Massachusetts General Hospital Fruit St. Boston MA USA 02030 Dr. Gerard M. Debrun Radiology The Johns Hopkins Hospital Meyer 8-140, 600 N. Wolfe St. Baltimore MD USA 21205

Dr. Stanley Barnwell Radiology UCSF Box 0628, Rm. L352, Neuroradiology San Francisco CA USA 94143

Dr. Jacques E. Dion Radiological Sciences UCLA Medical Ctr., BL-121 10833 Le Conte Ave. Los Angeles CA USA 90024-1721

Dr. Alex Berenstein Radiology NYU Medical Center 560 First Avenue New York NY USA 10016

Dr. Christopher Dowd Interventional Neuroradiotogy UCSF Medical Ctr., L-352 505 Parnassus Ave. San Francisco CA USA 94143-0628

Dr. Ricardo Garcia Monaco Neuroradiotogie Vasculaire H6pitat Bicetre 79 rue du General Leclerc Le Kremlin Bicetre France 94275 Dr. Robert C. Dawson Radiology Emory University 1364 Clifton Rd., NE Atlanta GA USA 30322 Dr. John Deveikis Radiology Georgetown University Hospital 3800 Reservoir Rd. Washington DC USA 2007-2197 Dr. Dong-Ik Kim Diagnostic Radiology Yonsei University College of Medici C.P.O. Box 8044 Seoul Republic of Korea Dr. Gary R. Duckwiler Radiological Sciences UCLA Medical Ctr., B2-188 10833 Le Conte Ave. Los Angeles CA USA 90024 Dr. Daniele Leonardo Maria Fiore Neuroradiologia U.L.S.S. No. 21 Via Giustiniani Padova Italy 35100 Dr. Allan J. Fox Radiology University Hospital 339 Windermere Rd. London Ont. Canada N6A 5A5 Dr. Glen Geremia Radiology Rush-Presby-St. Luke's Med Ctr. 1753 West Congress Pkwy. Chicago IL USA 60612

S 255 Dr. Anil Gholkar Regional Neurosciences Ctr. Newcastle General Hospital Westgate Rd. Newcastle Upon Tyne UK NE4 6BE

Dr. Van V. Halbach Radiology UCSF 505 Parnassus Ave. San Francisco CA USA 94143

Dr. Jill V. Hunter Nat. Hosp. for Nervous Diseases Lysholm Dept. of Radiology Queen Square London UK WCIN 3BG

Dr. Katsuya Goto Interventional Neuroradiology Iizuka Hospital 3-83 Yoshio-Machi Iizuka Japan 820

Dr. Stephen T. Hecht Diagnostic Radiology School of Medicine 2516 Stockton Blvd. Sacramento CA USA 95817

Dr. John Jacobs Radiology Univ. of Utai Medical Center 50 North Medical Drive, Room 1A71 Salt Lake City UT USA 84132

Dr. Douglas A. Graeb Radiology Vancouver General Hospital 855 West 12th Ave. Vancouver B.C. Canada V5Z 1M9

Dr. Randall T. Higashida Radiology 505 Parnassus Ave. Box 0628 San Francisco CA USA 94143

Dr. Laksham Jayasinghe Radiology Holy Spirit Hospital 259 Wickham Tce. Brisbane QLD Australia 4000

Dr. Leopoldo Guimaraens Clinica Quiron Paseo Mariano Renovales S/U Zaragoza Spain 50006

Dr. L. N. Hopkins Neurosurgery State Univ of New York at Buffalo 3 Gates Circle Buffalo NY USA 14209

Dr. Anil P. Karapurkar Neurosurgery K.E.M. Hospitals Parel Bombay India 400072

Terry G. Horner, MD Dept. of Neurosurgery Methodist Hospital 1801 N. Senate Blvd. Indianapolis IN USA 46202

Dr. Charles William Kerber Radiology, H-756 UCSD Medical Center 225 Dickinson St. San Diego CA USA 92103-1990

Dr. Yuo Iizuka Neuroradiologie Vasculaire L'H6pital Kremlin-Bicetre 78 Rue du General-Leclerc Kremlin-Bicetre France 94275

Dr. Mark Khangure Magnetic Resonance Imaging QEII Medical Centre Verdun St. Nedlands Western Australia Australia 6009

Dr. Tim Jaspan Radiology Queen's Medical Center Nottingham UK NG7 2VH

Dr. Eddie Sui Ki Kwan Radiology New England Medical Center 750 Washington St., Box 88 Boston MA USA 02111

Dr. Carl Wayne Hardin Radiology Medical Center Tower 7950 Floyd Curl Dr. Suite 201 San Antonio TX USA Dr. Grant Hieshima Radiology UCSF Room L352 505 Parnassus San Francisco CA USA 94143 Dr. Jonathan E. Hodes Neuroradiology H6pital Lariboisiere 2, rue Ambroise Pare Paris France 75010 Dr. James Gillespie Neuroradiology Manchester Royal Infirmary Oxford Rd. Manchester UK M13 9WL Dr. Augusto Goulao Neuroradiology Hospital Egaz Moniz R. Junqueira Lisbon Portugal 1200 Dr. Guido Guglielmi Neurological Sciences University of Rome Viale dell'Universita' 30/a Rome Italy 00815

Dr. Charles A. Jungreis Radiology Presbyterian University Hospital Pittsburgh PA USA 15213 Dr. Brian Kendall Lysholm Radiological Dept. The National Hospital for Neurology and Neurosurgery Queen Square London UK WC1N 3BG Dr. Axel deKersaint-Gilly Neuro-Radiologie Hopital G. et R. Laennec Nantes France 44035

Dr. Richard Latchaw Radiology Swedish Medical Center 501 E. Hampden Englewood CO USA 80110 Dr. Luis Lopez-Ibor Neuroradiology Clinica La Paloma La Loma No. 1 Madrid Spain 28003 Dr. Jean Claude Marchal Neurosurgery H6pital Saint-Julien 1 rue Foller NANCY France

S 256 Dr. Bharat A. Mehta Radiology Henry Ford Hospital 2799 W. Grand Blvd. Detroit MI USA 48202

Dr. Makoto Negoro Neurosurgery Dept. Nagoya University School of Medicine 6-15 Tsuruma-cho Showa-ku, Nagoya Japan 466

Dr. Ronie Leo Piske Med Imaging Hosp. Beneficencia Portuguesa Maestro Cardim, 769 Sao Paulo Brazil 01323

Dr. Andrew J. Molyneux Neuroradiology Dept. Radcliffe Infirmary Oxford UK OX 1 5 MN

Dr. Shogo Nishi Neurosurgery Faculty of Medicine, Kyoto University 54 Kawahara-chou, Shougo-in, SakyoKyoto City Japan 606

Dr. Charles A. Raybaud Radiologie H6pital Nord Chemin des Bourrelly Marseille France 13326

Dr. David Pelz Radiology University Hospital 339 Windermere Rd. London Ont. Canada N6A 5A5

Dr. George Rodesch Vascular Neuroradiology H6pital Bicetre 78 Avenue du G. Leclerc Le Kremlin-Bicetre France 94275

Dr. John Pile-Spellman Radiology Massachusetts General Hospital Fruit St. Boston MA USA 021 I4

Dr. Luciano Sabattini Neuroradiology Bellaria Hospital Via Altura No. 3 Bologna Italy 40139

Dr. Nello Quilici Neuroradiologia Ospedali Riuniti Via Alfieri Livorno Italy

Dr. Nina Sacharias Radiology Alfred Hospital Commercial Road Melbourne Australia 3181

Dr. Bernd Richling Neurosurgery Medical School University of Vienna Vienna Austria A-1090

Dr. William Paul Sanders Diagnostic Radiology Henry Ford Hospital 2799 W. Grand Blvd. Detroit MI USA 48202

Dr. Daniel A. Ruefenacht Diagnostic Radiology Mayo Clinic Rochester MN USA 55905

Dr. Giuseppe Scotti Neuroradiotogy Ospedale San Raffaele Via Olgettina 60 Milan Italy 20132

Dr. Jacques Moret Interventional Neuroradiology Fondation Rothschild 25-29 Rue Manin Paris France 75019 Dr. Pierre L. Lasjaunias Radiologie H6pital Bicetre 78 rue du General Leclerc Kremlin Bicetre France 94275 Dr. Feng Ling Neurosurgery General Hospital of PLA 28, Fuxing Road Beijing China 100853 Dr. Claude Manelfe Neuroradiotogy H6pital Purpan Toulouse France 31059 Dr. Michel Mawad Radiology The Methodist Hospital 6565 Fannin Houston TX USA 77030 Dr. J. Jacques Merland Diagnostic & Interventional Neurora H6pital Lariboisiere 2, rue Ambroise Pare Paris France 75017 Dr. Lee H. Monsein Radiology Johns Hopkins Hospital Meyer 8-140, 600 N. Wolfe St. Baltimore MD USA 21205 Dr. Per Hjalmar Nakstad Rikshospitalet Pilestredet 27 Oslo 7 Norway 0027

Dr. Yasunari Niimi Dept. of Neurosurgery Tokyo Medical and Dental University 1-5-45 Yushima, Bunkyo-ku Tokyo 113 Japan Dr. Asher Nov Dept. of Radiology Group Health Coop of Puget Sound 200 15th Ave. Seattle WA USA 981 t2 Dr. Luc Picard Neuroradiology Centre Hospitalo-Universitaire H6pital Saint-Julien - C.O 34 Nancy France 54035

Dr. William A. Sorby Radiology Royal North Shore Hospital St. Leonards Sydney NSW Australia 2065 Dr. Paul Svendsen Sahlgrenska Hospital Goteborg Sweden S-413 45 Dr. Waro Taki Neurosurgery Kyoto University Medical School 54 Kawaharacho, Shogein, Sakyoku Kyoto Japan

S 257 Dr. Akiyo Sadato Dept. of Neurosurgery Kyoto Univ. School of Medicine 54-KaVeahara-cho Shogoin Kyoto Japan 606

Dr. Ian Turnbull X-ray Department North Manchester Hospital Delauneys Rd. Crumpsall, Manchester UK M8 6RB

Dr. Maria Antonietta Vaghi Neuroradiology Institnto Neurologico Via Celoria 11 Milano Italy 20131

Dr. John Scott Radiology Methodist Hospital 1701 N. Senate Indianapolis IN USA 46202

Dr. Anton Valavanis Neuroradiology University Hospital Zurich Frauenklinikstrasse 10 Zurich Switzerland 8091

Dr. Fernando Vinuela Endovascular Therapy UCLA Medical Center 10833 LeConte Ave. Los Angeles CA USA 90024-1721

Dr. Robert R. Smith Dept. of Neurosurgery University Hospitals & Clinics 2500 North State St, Jackson MI USA 39216-4505

Dr. Jiri Vitek Radiology Univ Alabama/Birmingham 619 South 19th St. Birmingham AL USA 35233

Dr. John Whitaker Radiology St. Anthony Hospital West 17th St. Denver CO USA

Charles Strother Radiology University of Wisconsin 600 N Highland Madison WI USA 55711

Dr. Gunnar Wikholm Sahlgrenska Hospital S 41345 Goteborg Sweden

Dr. Robert Willinsky Radiology Toronto Western Hospital 399 Bathurst St. Toronto Ontario Canada M5T 2S8

Dr. Akira Takahashi 4-20-1, Nagamachi, Minami Sendai Miyagi Japan 982

Dr. Harvey Wilner Radiology Harper Hospital 3990 John R. Detroit MI USA 48201

Dr. Karel G. TerBrugge Radiology Toronto Western Hosp. 399 Bathurst St. Toronto Ont. Canada M5T 2S8

Dr. Peter J. Yang X-Ray Medical Group Grossmont Hospital 5565 Grossmont Center Dr., Ste. 1 La Mesa CA USA 92042-3076

Dr. Jacques Theron Dept. of Neuroradiology UCLA 1200 North State St. Los Angeles CA USA 90033

Dr. Brian M. Tress Radiology PO Royal Melbourne Hospital Melbourne Australia 3050

Dr. Christian Wriedt Diagnostic Radiology Austin Hospital Studley Rd. Heidelberg Australia 3084 Dr. David A. Yates Radiology/Midland Ctr. for Neurology/Neurosurgery Holly Lane, Smethwick Warley, West Midlands UK B67 7JX