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SCIENTIFIC PAPERS 1 MAGNETIC RESONANCE IMAGING IN PRETERM INFANTS MAY PREDICT LATER CEREBRAL PALSY Patrick Barnes, MD, Radiology, Lucile Packard Children’s Hospital at Stanford, Palo Alto, CA; Yervant Arzoumanian, MD; Majid Mirmiran, MD; Scott Atlas, MD; Michael Moseley, Ph.D; Ronald Ariagno, MD Purpose: To assess diffusion tensor imaging (DTI) as a predictor of cerebral palsy (CP). Materials and Methods: 62 preterm infants (GA 33wk or less) had MRI near term at 1.5T with conventional (cMRI) and DTI sequences. Whole-brain ADC & FA histograms were generated along with regional (ROI) ADC and FA maps. The cMRIs were first scored for abnormalities [category C1= no abnormality; C2 ¼ grade 1 subependymal hemorrhage or mineralization only; C3 ¼ ventriculomegaly; C4= parenchymal abnormality, e.g. periventricular leukomalacia (PVL); C5 ¼ malformation]. All infants had follow up neurodevelopmental assessments. Results: There were 37 infants in the C1 category, 19 in C2, 2 in C3, 3 in C4, 1 in C5. Neurodevelopmental follow up is available in 35 infants. Two of the C4 group have CP. Four in the C1 and C2 groups have CP. DTI of these four patients were further analyzed. The whole brain ADC and FA histograms showed no significant differences between CP and non-CP infants. However, ROI analyses showed a significant reduction of FA in the splenium (.351 + .065 vs. .463 + .074; p=0.003) and in the posterior limb of the right internal capsule (.360 + .036 vs. .421 + .037; p=0.006) in CP vs. non-CP patients. Conclusions: The decrease in FA is consistent with disordered neuroaxonal development in preterms who later developed CP. DTI may enhance the ability of MRI in predicting long term outcome.

2 PRENATAL DETECTION OF SPINAL ANOMALIES IN ASSOCIATION WITH CONGENITAL DIAPHRAGMATIC HERNIA* Joan T. Rubin, BA, Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Erin M. Simon, MD, OTR; Roman Sydorak, MD; Amar Nijagal, BS; Mark P. Johnson, MD; Larissa T. Bilaniuk, MD; et al Purpose: To call attention to the association of spinal anomalies in the setting of congenital diaphragmatic hernia (CDH) and the significance of prenatal detection. Materials and Methods: Retrospective review of clinical records of the Centers for Fetal Diagnosis and Treatment at The Children’s Hospital of Philadelphia and the University of California, San Francisco, to estimate incidence of detected spinal anomalies in fetuses with CDH. Ultrasound and fetal MR studies were reviewed to correlate type, location, and extent of hernia with spinal anomalies. Results: Since 1995, 9 (2.7 %) of 337 fetuses assessed for CDH were recognized to have associated spinal anomalies (7F, 2M). 7 were definitively diagnosed or highly suspected prenatally; two were undiagnosed and underwent in utero tracheal occlusion. All fetuses had left sided CDH and normal karyotype. Lung-head ratios ranged from 0.6–1.15 (n ¼ 7, mean 0.95). Cervical or cervical/ thoracic junction levels were most commonly involved (8 fetuses; 7

non-survivors, one lost to follow-up, presumed non-survivor). The only known survivor had an L5 spina bifida occulta. Conclusions: Although uncommon, spinal anomalies in the setting of CDH have a dismal outcome, even after in utero surgery. Recognition of these additional anomalies is vital for accurate counseling and pregnancy management decisions.

3 PRENATAL MRI OF THE FETAL URINARY TRACT Anne M. Hubbard, MD, Radiology, Surgery, Urology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania; N. Scott Adzick, MD; Mark Johnson, MD; Douglas A. Canning, MD Purpose: 1 in 1,000 fetuses have renal anomalies. Mortality of fetal uropathy is 20–50 %. Ability to counsel families, plan termination or interventional procedures depends on accurate diagnoses. Purpose of this study was to evaluate accuracy of MRI evaluation of the fetal urinary tract (UT) and impact on therapy. Methods: Retrospective review of charts, MRI and US of 54 patients with UT abnormality. Evaluated on MRI and US: renal cortical thickness, echogenicity/signal, cysts/dysplasia, dilation of collecting system, bladder size, wall thickness, and amniotic fluid. The findings were correlated with postnatal studies or autopsies. Any change in prenatal therapy based on the MRI findings were documented. Results: Diagnoses: renal agenesis (5), cloacal abnormality (4), MCDK (2), pelviectasis, UPJ (6), ureterectasis (3), lower UT obstruction (27), dysplasia (4), polycystic kidney (1), duplex (2). MRI diagnosis correlated with followup studies in all. MRI improved diagnosis of renal dysplasia in isolated dysplasia and with lower UT obstruction in 10 % of cases. MRI accurately diagnosed all cloacal abnormalities which excluded the fetus from prenatal therapy. MRI demonstrated distal ureteral dilation not seen on US in 3 fetuses. MRI significantly improved evaluation of fetus with severe oligohydramnios, distortion of UT caused by severe dilation, and cloacal abnormalities.

4 PRENATAL MRI OF FETAL VENTRAL WALL DEFECTS Anne M. Hubbard, MD, Radiology, The Children’s Hospital of Philadelphia, Philadephia, Pennsylvania; Holly Hedrick, MD Purpose: Evaluate accuracy and efficacy of MRI for evaluation of ventral wall defects. Methods: Retrospective review of charts, MRI and US of patients with ventral wall defects. Evaluated site and extent of defect from chest to pubis and compared with postnatal evaluation and autopsy. Results: Evaluated 36 fetuses. Ectopic cordis 1, omphalocele 14, pentalogy 3, gastroschesis 4, body stalk 6, cloacal extrophy 6, umbilical cord hernia 2. MRI accurately diagnosed all defects of the chest, abdomen, and pelvis. Cord insertion seen in all. MRI diagnosed chest defect not seen on US associated with abdominal defect in 5, which changed diagnosis and counseling. Valuable in defining chest wall defects associated with pentalogy and body stalk abnormalities, able to define cortical bone and cartilage of chest and spine. Accurately diagnosed cloacal extrophy in all, better definition of bowel than US, lack of meconium seen in a rectum with cloaca, which is demonstrated in normal fetuses. Accurately diagnosed all body stalk abnormalities with may be confused with gastroschesis or ruptured omphalocele. MRI changed diagnosis in 15 % of fetuses.

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5 USING SENSIVITY ENCODING (SENSE) ACCELERATION AND INNER VOLUME IMAGING (ZOOM) TECHNIQUES TO MINIMIZE RADIO-FREQUENCY EXPOSURE AND TO SHORTEN IMAGE ACQUISITION DURATION IN FETAL MR: WORK-IN-PROGRESS Taylor Chung, M.D., Edward B Singleton Dept of Diagnostic Imaging, Texas Children’s Hospital, Houston, Texas; Raja Muthupillai, Ph.D.; Richard M. Braverman, M.D.; Christopher I. Cassady, M.D. Introduction: Single-shot turbo spin echo (SShTSE), which requires a train of multiple 180 degrees radio-frequency (RF) refocusing pulses deposited in a short duration, is widely used in fetal MR. RF energy deposition and acquisition time are related to the echo-train length (ETL) and echo-spacing (ESP). Purpose: Apply MR techniques, SENSE and Zoom, to decrease energy deposition and acquisition duration by reducing the number of RF refocusing pulses. Methods: On a clinical 1.5T MR system, the following sequences with TE ¼ 60 milliseconds (msec) were performed on a phantom and a non-gravid volunteer: (A) TSE (ETL ¼ 128, ESP ¼ 4.3 msec), (B) SShTSE with SENSE (ETL ¼ 66, ESP ¼ 4.3 msec), (C) SShTSE with Zoom (ETL ¼ 52, ESP ¼ 5.3 msec) with respiratory triggering, (D) SShTSE with SENSE plus Zoom (ETL ¼ 28, ESP ¼ 9.5 msec) with respiratory triggering. These sequences were applied in 3 clinical cases (3rd trimester). Results: Calculated relative reduction of energy deposition and acquisition duration per image for sequences A, B, C, D, were: 1, 0.25, 0.09, 0.07 and 563 msec, 284 msec, 275 msec, 266 msec respectively. The clinical images were considered to be of diagnostic quality by 3 pediatric radiologists. Conclusion: Preliminary work suggests SENSE and Zoom with SShTSE can yield diagnostic quality images with decrease in energy deposition and acquisition duration per image.

6 GREY SCALE AND COLOUR DOPPLER SONOGRAPHY OF THE NORMAL NEONATAL BOWEL* Ricardo Faingold, MD, Department of Diagnostic Imaging, The Hospital for Sick Children and the University of Toronto, Toronto, ON, Canada; Alan Daneman, MD, FRCPC; David Manson, MD, FRCPC; Paul Babyn, MD, FRCPC; George Tomlinson, PhD; Arun Mohanta; et al Purpose: To determine normal neonatal bowel appearances and whether bowel wall perfusion can normally be detected with Colour Doppler Sonography (CDS). There is no published data. Materials and Methods: Bowel was studied in 20 fasting neonates without evidence of bowel or cardiovascular disease. (12M; 8F, GA: 24–41 w, corrected age: 31 w–45 w, mean 39 w). Sonography was performed with linear transducers (8–15 MHz). The abdomen was sampled in four quadrants. Bowel wall echotexture, wall thickness, peristalsis and mural blood flow were evaluated. Colour Doppler (CD) was performed to assess mural blood flow (# of CD signals-dots and lines/cm2). Velocity was set at 0.057–0.11 m/s. CD flow was determined to be present when CD signals were reproducible or documented with pulsed waveforms. Descriptive statistics were calculated for measurements derived from CDS. Results: Bowel thickness ranged from 1–2.6 mm (mean 1.61 +/ )0.4). Peristalsis was a minimum of 10 contractions/minute in all. Bowel wall perfusion was seen in all 20(80 quadrants). CD signals ranged from 1–6 dots/cm2 (mean 3.25 +/) 0.46), in all

quadrants. Linear CD signals were not always seen in all quadrants and ranged from 0–2 thin lines per cm2 (mean 0.81 +/)0.25). Conclusion: This study has documented that bowel wall perfusion can be detected in the normal neonate by CDS and provides baseline information to evaluate neonates with suspected bowel necrosis.

7 BOWEL VIABILITY ASSESSMENT BY COLOUR DOPPLER SONOGRAPHY IN NECROTIZING ENTEROCOLITIS* Ricardo Faingold, MD, Department of Diagnostic Imaging, The Hospital for Sick Children and the University of Toronto, Toronto, ON, Canada; Alan Daneman, MD, FRCPC; David Manson, MD, FRCPC; Paul Babyn, MD, FRCPC; George Tomlinson, PhD; Arun Mohanta; et al Purpose: To determine whether the absence of bowel wall perfusion with Colour Doppler sonography (CDS) in neonates with necrotizing enterocolitis (NEC) indicates bowel necrosis. Materials and Methods: A prospective analysis of 13 neonates with NEC (11 preterm and 2 term, 8M:5F, 24–40 w GA, corrected age: 25–46 w). CDS of mural blood flow was obtained with linear transducers (8–15 MHz). Bowel wall echogenicity, wall thickness, mural air and peristalsis were evaluated. Comparison was made with radiographs and Bell’s Clinical Criteria for NEC. Results: CDS in all 7 with mild to moderate NEC (Bell stages I and II) showed increased bowel perfusion. Six did well clinically. The 7th (with moderate NEC) had one segment of bowel with absent blood flow. Laparotomy disclosed a loop of necrotic bowel corresponding to the CDS abnormality.CDS depicted multiple segments of absent bowel perfusion in all 6 patients with severe NEC (Bell Stage III). Three patients had pathologic confirmation (1 laparotomy, 2 autopsies) of bowel necrosis corresponding to the areas of absent perfusion. Of the other three, two had perforation with pneumoperitoneum and had peritoneal drains placed. Five of the 6 died. Conclusion: CDS evaluation of the neonatal bowel appears to be a useful method for depicting bowel wall perfusion changes in NEC. Absence of perfusion is indicative of bowel necrosis.

8 OVAL CALCIFIC DENSITY IN THE RIGHT-UPPER QUADRANT IN A YOUNG INFANT: CALCIFICATION OF THE UMBILICAL RECESS Alan E. Schlesinger, M.D., E. B. Singleton Department of Diagnostic Imaging, Texas Children’s Hospital, Houston, Texas; Richard M. Braverman, M.D. Vascular calcifications in the right-upper quadrant of radiographs in young infants have been described in the inferior vena cava (IVC), portal vein, and ductus venosus. We recently encountered a 2-month old boy (with a history of prior umbilical vein catheterization) with extensive right-upper quadrant calcification of the entire course of the catheter including the umbilical vein, a portion of the left portal vein, the ductus venosus, and the IVC as well as multiple hepatic venous branches. However, the most dramatic portion of the calcified tract was an oval focus in the umbilical vein just before its entrance to the left portal vein. This structure, the umbilical recess, has been described by anatomists, and knowledge of this structure is important as it can be useful in identifying complications of umbilical vein catheters.

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9 MRI ASSESSMENT OF FETAL POSTERIOR FOSSA VOLUME* Sara C. Chen, BS, School of Medicine, University of Pennsylvania, Philadelphia, PA; Erin M. Simon, MD, OTR; John Haselgrove, PhD Purpose: To establish a normal growth curve for the total posterior fossa volume (PFV) during pregnancy. Materials and Methods: A cross-sectional, retrospective study was done of PFV in 79 fetuses (18–36 weeks) with normal central nervous system on in vivo fetal MR images. Results: Student t tests indicated no significant difference in volumes measured from different image orientations (p > 0.2 for all comparisons), so results were averaged. The relationship between average PFV and gestational age is well described by a single exponential growth curve. Doubling time is 6.29 weeks. Root mean square variation of values about the model line is 1.62 cc. Preliminary investigation of inter-observer variability indicates a small (1.0 cc) systematic difference between observers. This is smaller than the random variation of 1.62 cc. We are currently tracing the source of this difference. Conclusions: MR imaging is a practical way of measuring the volume of the fetal posterior fossa between 18–36 weeks of gestation, and is expected to prove valuable in qualitatively assessing fetal anomalies. Measurements in the single plane in which the fetal PF is best visualized appear adequate for practical evaluation.

10 NEUROIMAGING OF THE NEONATE: AN EVIDENCE-BASED PRACTICE PARAMETER Patrick D. Barnes, MD, Radiology, Lucile Packard Children’s Hospital at Stanford, Palo Alto, CA; Laura R. Ment, MD; Ellen P. Grant, MD; Tom L. Slovis, MD; Henrietta S. Bada, MD; Lu A. Papile, MD; et al Purpose: To develop neuroimaging practice parameters for both very low birth weight (VLBW)/ preterm (PT) infants and encephalopathic term infants. Materials and Methods: Literature searches and classification of the strength of the evidence were done by a multidisciplinary committee using diagnostic and prognostic rating criteria (classes I–IV). Recommendations were made accordingly [A=standard, B=guideline, C=optional, D=not recommended]. Results: The search produced over 1320 citations, 90 of which met inclusion criteria. Conclusions: US should be done on all infants less than 30 weeks GA at 7–14 days of age and at 36–40 weeks PMA to detect early lesions (e.g. IVH) for clinical care [level B/class II] and later lesions (e.g. PVL and ventriculomegaly) for outcome [level A/class II]. There is insufficient evidence for routine MRI [level C/class II] in VLBW/PT infants with abnormal US. CT should be done for the encephalopathic term infant to rule out hemorrhage [level B/class II, IV]. If CT is noncontributory, MRI should be done between days 2 and 8 to assess extent of injury to provide both diagnostic and prognostic information (level A/class II]. Diffusion imaging may allow earlier detection [level C/class II, III]. In addition to conventional MRI, diffusion [level B/class II, III] or spectroscopy [level B/class II] may provide prognostic information.

11 ACUTE OSTEOCHONDRAL INJURY OF THE KNEE: A COMMON BUT UNRECOGNIZED LESION IN THE IMMATURE SKELETON* Rachel S. Oeppen, MB ChB, Pediatric Radiology, Massachusetts General Hospital, Boston, Massachusetts; Susan A. Connolly, MD; Jenny T. Bencardino, MD; Diego Jaramillo, MD Purpose: To test the hypothesis that acute osteochondral injuries (not previously studied by a large MRI series in children) are common on high-resolution MRI. Material and Methods: 82 children and adolescents with open physes (median age: 13.2 yr), had knee MRI for internal derangement evaluation using high-resolution proton density and T2weighted imaging. Results: 43 acute osteochondral lesions were found in 28 children (prevalence: 34 %); with 33 (77 %) involving the subchondral bone. Of these, 31 were femoral, 10 patellar, and 2 tibial. Femoral lesions were distributed equally between lateral (n=16) and medial (n=15) femoral condyles, and were more prevalent along the weight bearing region (58 %, P=.03). Bone bruising occurred in both femur (n=26) and tibia (n=24) and was more common laterally (29 vs. 21, P= .02). 24 surfacing meniscal lesions were seen in 19 patients (prevalence 23 %), and more commonly involved the lateral meniscus (16 vs. 8, P= .0004). Anterior cruciate ligament (ACL) injuries occurred in 20 patients. There was no association between meniscal and ACL injuries and osteochondral lesions. There were 4 physeal fractures (1 femoral, 3 tibial), and one avulsion fracture of the proximal fibular epiphysis. Conclusion: In skeletally immature patients studied for internal knee derangement, acute osteochondral lesions are the most prevalent injuries.

12 STERNAL FRACTURES IN CHILDREN AND THEIR RELATIONSHIP TO ABUSIVE INJURY David E. Manson, MD, FRCPC, Department of Diagnostic Imaging, The Hospital for Sick Children and the University of Toronto, Toronto, ON, Canada; Sloane Hechter, MSc; Dirk Huyer, MD Background: Sternal fractures are rare injuries in children. The rarity of this injury is likely due to the relative plasticity of the pediatric thorax. Current literature suggests that this injury is highly specific for abusive injury, especially in children under the age of three years. Hypothesis: Sternal fractures are not highly specific for abusive injury. Materials and Methods: This is a retrospective radiographic and clinical chart review of all documented sternal fractures over an 11 year period at a large pediatric hospital. Results: Twelve children with sternal fractures were identified. The mechanism of injury was attributed to child abuse in 0/10 children >3 years of age, and in 2/4 children <3 years of age. In one toddler, an un-witnessed injury resulted in extensive initial familial anxiety until abusive injury was excluded. In 8/10 cases attributed to accidental injury, direct sternal impaction rather than blunt trauma appeared to be the mechanism of injury. Conclusion: Sternal fractures are unusual injuries, yet, unlike some types of fractures, they, in themselves, are not highly specific for abusive injury.

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13 BONE AGE AND PROJECTED SURFACE AREA OF THE CARPAL BONES Pierre M. Braillon, PhD, MD; Pediatric Imaging, Hospital Debrousse, Lyon, France; Guillaume Trager, MSc; Jean P. Pracros, MD Purpose: To study the possible assessment of bone age from the surface area of the carpal bones (Ac) obtained by X-ray absorptiometry. Materials and Methods: We studied 207 children and adolescents (108 girls, 2.2–16.9 y., and 99 boys, 2.2–18.8 y., respectively). In this population, 13 girls suffered from Turner’s syndrome, and 27 children (9 girls, 18 boys) presented an intra-uterine growth retardation. These 40 particular patients were treated with growth hormone. The actual height (H) of the patients was close to the normal height (Hn) for age, and the ratio H/Hn was 0.99 ± 0.09 in the girls, and 0.96 ± 0.07 in the boys. A scan of the patients’ wrist was performed on a pDEXAÒ system from Norland Medical Systems, Fort Atkinson, Wi (scan speed 30 mm/s, scan line spacing 1.0 mm). The projected surface area of the carpal bones (Ac) was measured by two operators independently, within a region of interest specially defined. The patient bone age was estimated by the Greulich and Pyle method. Results: The precision of the measurements was better than 1 %. Ac values ranged from 0.34 cm2 to 13.68 cm2 in girls, and from 0.25 cm2 to 15.83 cm2 in boys. Correcting these values for height, as Ac x Hn/H resulted in a high linear correlations (r2 > 0.9) with radiographic bone age. Conclusion: The DXA technique could be used to assess bone age. The method is not operator dependent, and the precision seems better than ± 2 months.

14 T2 RELAXATION TIME MAPPING OF OSTEOCHONDROMAS: WHY INCREASED VALUES ARE NORMAL Tal Laor, MD, Department of Radiology, Children’s Hospital Medical Center, Cincinnati, Ohio; Bernard Dardzinski, PhD; Kevin E. Bove, MD Purpose: Cartilaginous caps of osteochondromas persistently show markedly increased T2 signal on MR imaging when compared to other cartilage. Our aim is to compare T2 relaxation times of these cartilage caps with other regions of hyaline cartilage, and to correlate with histology. Materials and Methods: Thirteen osteochondromas in 11 children (ages 5–17 years) underwent T2 relaxation time mapping (TE ¼ 9– 99/TR ¼ 1500 msec). Lesions were femoral=6, fibular=3, tibial=2, and scapular=2. Histology correlation was available for 7 lesions. T2 values were compared to those of physes and unossified epiphyses. Results: Average cap T2 times ranged from 151–366 msec. T2 times of distal femoral and proximal tibial physes, and epiphyses were 69–87 msec, and 40–62 msec, respectively. Osteochondral caps with the highest average T2 values showed relatively increased numbers of hypertrophic chondrocytes. These hypertrophic chondrocytes demonstrated less columnar organization than is typical of normal physeal cartilage. Conclusion: T2 relaxation times of osteochondral caps were persistently higher than values obtained from other pediatric cartilage. There is a positive correlation between T2 relaxation times and cellularity of the cartilage, and a negative correlation to the degree of cellular organization. Marked hyperintense T2 signal should not be considered abnormal when evaluating osteochondral caps.

15 UNDERSTANDING THE FUNCTIONAL ANGIOGENIC PROCESS IN AN ANTIGEN-INDUCED ARTHRITIS MODEL: BOLD MR IMAGING (FMRI) CORRELATION WITH THE STAGES OF SYNOVITIS ALONG THE TIME COURSE OF THE DISEASE* Andrea S. Doria, MD, Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada; Paul S. Babyn, MD; Adrian Crawley, PhD; Mike Noseworthy, PhD; Kenneth Pritzker, MD; Robert B. Salter, MD; et al Purpose: To test the feasibility of BOLD MR imaging for evaluation of the synovial response of the knee to a hyperoxic stimulus. Materials and Methods: fMRI (1.5T GE MR scanner) was performed in 16 arthritic juvenile rabbits (32 knees) after injection of ovalbumin in one of the knees (arthritis induction) and of saline (placebo) in the contralateral knee, and in 2 control juvenile rabbits (4 knees). Sets of 2 rabbits were sacrificed at 4, 10, 24, 48 hours, 7, 14, 21 and 28 days from arthritis induction, upon the end of examination. Each scan (3:04 min) consisted of three 30-sec-hyperoxic paradigms (100 % oxygen/mask) alternated with three 30-sec-normoxic paradigms. T2*-weighted sequences were used (TE/TR=40/2000 msec, flip angle=90°, FOV=70 mm, matrix=264, thickness/gap=4/0 mm, NEX=2). Results: Activated voxel ratios of arthritic/contralateral knees at 4 (154 %), 10 (117 %), 24 (271 %), 48 (197 %) hours and 7 (112 %) days (initial arthritic stages) were significantly higher than normal knee ratios (26 %). Subsequently there was an inversion in the activation pattern at 14 ()0.6 %), 21 ()8 %) and 28 ()68 %) days (decreased response). A quadratic trend for the slope was estimated by negative time squared values ()0.47), P=0.07 (ANOVA).BOLD MR imaging is a feasible method for evaluation of synovial response to a hyperoxic stimulus what might be useful to predict the potential synovial response to therapy at a certain timepoint of the disease.

16 SPINE BONE DENSITOMETRY IN ASTHMATIC CHILDREN TREATED WITH HIGH DOSE CORTICOSTEROIDS: CORRECTING FOR RACIAL DISCREPENCIES S. Bruce Greenberg, MD, Radiology, Arkansas Children’s Hospital, Little Rock, AR; Pippa M. Simpson, PHD; Stacy M. Jones, MD; Sharla Holloway; Joanna J. Seibert, MD Purpose: High dose steroid therapy for asthmatic children reduces bone mineralization. Bone density is greater in African American children (AAC) than Caucasians (CC) resulting in under-reporting abnormal bone density in AAC if a common standard based on CC is applied. Our aim was to show how to correctly assess bone density in both races. Methods: Spine bone densitometry was performed on 82 AAC and 80 CC receiving high dose steroid therapy for asthma. Z-values using a common standard were calculated to assess bone density. 32 zvalues specific for AAC were used in a regression analysis with the AAC values as dependent and the common values as independent. Results: Using the common z-values, the mean 0.18 for AAC was significantly higher than )0.57 for CC, p<0.002) and the incidence of abnormal bone mineralization was greater in CC [(29 cc, 36 %) versus 16 AAC (20 %), p<0.015)]. From regression, z-value specific for AAC ¼ (calculated z-value) )0.86. Using this equation for all AAC resulted in increased detection of abnormal mineralization (38 AAC, 46 %). The difference in incidence between AAC and CC abnormal bone mineralization is no longer significant (p>0.12). Conclusion: Standards developed for CC can be adjusted for use in AAC by using a simple regression equation. AAC have the same incidence of bone demineralization as CC receiving high dose steroid therapy for asthma.

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17 CONTRAST-ENHANCED TRIGGERED HARMONIC SONOGRAPHY FOR QUANTIFICATION OF SYNOVIAL BLOOD FLOW IN AN ANTIGEN-INDUCED ARTHRITIS MODEL: PRELIMINARY RESULTS OF MICROBUBBLE DESTRUCTIONREPERFUSION AND WASH-IN/WASH-OUT CURVES* Andrea S. Doria, MD; Diagnostic Imaging, Hospital for Sick Children, Toronto, ON, Canada; Paul S. Babyn, MD; Peter Burns, PhD; Raffi Kharchakdjian; Arun Mohanta, RT; Stephanie Holowka; et al Purpose: To investigate the use of contrast-enhanced pulse inversion gray-scale harmonic sonography for evaluation of synovial blood flow along time in an antigen-induced arthritis model. Materials and Methods: 10 juvenile rabbits (20 knees) including 2 control rabbits underwent US examination using 7 MHz lineararray probes-HDI 5000, ATL. Eight rabbits were injected ovalbumin (induction of arthritis) in one knee and saline in the contralateral knee being imaged at 4, 10, 24, 48, hours, 7, 14, 21 and 28 days of arthritis induction and then were harvested. A continuous infusion (destruction-reperfusion) protocol (10 microliters/kg in 50 ml saline-DefinityÒ, Bristol-Myers Squibb, MI=0.21, triggering times=30, 20, 10, 5, 2, 1, 0.5 sec) was followed by a bolus injection (wash-in/wash-out) protocol (10 microliters/kg, MI=0.06). Results: Times to peak were longer for arthritic knees at all timepoints (P=0.03, difference in regression lines intercepts) but enhancement intensity was higher for contralateral knees (P=0.09). Synovial vascular volume and flow rate were higher for contralateral knees (P=0.05 and 0.009 respectively) with a decrease in the contralateral/arthritic knee vascular flow ratio along time (range: 17 %=4 h to 1.9 %=28 days)/normal knee ratio= 0.17 %. Contrast-enhanced imaging demonstrated a functional variation in the pattern of microbubble destruction-reperfusion and wash-in/wash-out curves between arthritic, saline-injected and control knees along time. (Support of contrast material provided by Bristol-Myers Squibb Medical Imaging, Boston, MA).

18 ACUTE HEMATOGENOUS OSTEOMYELITIS OF CHILDREN: ASSESSMENT OF SCINTIGRAPHY-BASED DIAGNOSIS IN THE ERA OF MRI Susan A. Connolly, MD, Pediatric Radiology, Massachusetts General Hospital, Boston, MA; Leonard P. Connolly, MD; Laura A. Drubach, MD; S. T. Treves, MD; Diego Jaramillo, MD Purpose: To evaluate a strategy using skeletal scintigraphy as primary modality and MRI as supplemental in suspected acute hematogenous osteomyelitis (AHO). Materials and Methods: We reviewed records of 213 children with possible AHO and non-diagnostic radiographs, referred for skeletal scintigraphy. MRI was obtained when diagnostic uncertainty persisted after scintigraphy or when abscess was suspected because of anatomic location or poor antibiotic response. Results: Scintigraphy detected 79 of 86 (92 %) cases with final diagnosis of AHO, with none indicated only by MRI. Of 34 children undergoing MRI for diagnostic uncertainty after scintigraphy, there was extraosseous pathology in 20 (59 %) [synovitis (n=10), myositis (n=5), other abnormalities (n=5)] and no pathology in 8 (24 %). Of 33 children with suspected abscess, MRI showed abscess in 15 (45 %): 6 of 15 (40 %) studied due to concern at diagnosis (5 pelvic, and 1 spinal) and 9 of 18 (50 %) evaluated for poor antibiotic response. Abscesses were drained in 3 (6 %) of 48 cases of long bone AHO, and in 5 of 25 (20 %) cases of pelvic AHO. In Conclusion: a) scintigraphy effectively detects bone infection; b) in equivocal scintigrams, MRI often shows extraosseous pathology;

and c) when there is pelvic infection or poor therapeutic response, MRI often demonstrates abscesses.

19 RADIOGRAPHIC FEATURES OF BISPHOSPHONATE THERAPY IN PEDIATRIC PATIENTS Leslie E. Grissom, M.D., Department of Medical Imaging, A.I. duPont Hospital for Children, Wilmington, Delaware; H. Theodore Harcke, M.D. Increasing numbers of children at risk for fracture are receiving bisphosphonate therapy. Distinctive radiographic findings such as dense metaphyseal bands have been reported in these patients. Radiographs of 35 patients on pulsed dose bisphosphonate therapy were reviewed. Multiple metaphyseal bands were seen in the long bones corresponding to the doses of bisphosphonates, varying in spacing according to the rate of growth. The increased density reflects the decrease in osteoclastic activity produced by the medication. Plain film findings of pulsed bisphosphonate therapy are readily recognizable in the growing skeleton. This presenter has disclosed that a pharmaceutical that has not cleaned the FDA for specific ‘‘off-label’’ use is being presented.

20 THE SONOGRAPHIC PATTERNS OF PRIMARY HYPEROXALURIA OF TYPE 1 IN CHILDREN* Oussou Diallo, MD; Fred E. Avni, MD, PhD, Pediatric Imaging, University Children’s Hospital Queen Fabiola, Brussels, Belgium; Francoise Janssen, MD; Michelle Hall, MD Purpose: To determine the sonographic (US) patterns of primary hyperoxaluria of type 1 (HP1) in children and the relation between US patterns and the development of renal failure. Material and methods: The US examinations– at diagnosis and during follow-ups – of thirteen affected patients were analyzed by two observers. US findings were correlated with corresponding biological data. Results: On the basis of the US findings at diagnosis, the patients were separated into two groups. Five patients (4 neonates) with cortical nephrocalcinosis; all 5 developed renal failure rapidly and 4 were transplanted. Seven patients (no neonates) presented medullary nephrocalcinosis; only 2 developed renal failure and were transplanted; in both, a diffuse medullary nephrocalcinosis with acoustic shadowing persisted during all US follow-up studies. There was a good agreement between the two observers. Conclusion: HP1 may present under two different US patterns: cortical and medullary nephrocalcinosis. Cortical nephrocalcinosis has a poor prognosis in terms of renal function. Among patients with medullary involvement, the persistance during follow-up of a marked and diffuse nephrocalcinosis is also predictive the development of renal failure.

21 ROLE OF IMAGING IN THE MANAGEMENT OF CHILDHOOD EMPYEMA Aruna Vade, MD; Jennifer Lim-Dunham, MD; Carla Harmath, MD Purpose: To assess the role of imaging in the management of childhood empyema. Methods: This is a retrospective study on 22 children who presented with parapneumonic fluid effusions. All children failed antibiotic therapy. The clinical outcomes in these children were correlated with

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imaging modalities and therapeutic interventions. Chest radiographs, US and CT were used to define the extent and characterize the parapneumonic effusions both before and after the therapeutic interventions. Therapeutic interventions included thoracostomy tubes (n=11), thoracostomy tubes with intrapleural urokinase administration (n=4), video assisted thoracoscopy with lysis of adhesions (n=2), decortications (n=13) and partial lobectomies (n=2). Results: The mean age of the children was 3.4 years. Mean duration of symptoms prior to the admission was 5 days and mean duration of hospital stay was 13 days. 50 % of thoracostomy tubes and 25 % of intrapleural urokinase failed to treat empyema when imaging showed multiple loculations and thick pleural rinds. In these patients, video assisted thoracostomy with lysis of adhesions or decortication procedure resulted in prompt resolution of symptoms. Conclusion: Imaging can play an important role in the management of childhood empyema. Review of clinical outcome suggests that when cross sectional imaging shows multiloculated parapneumonic exudates, aggressive surgical intervention may decrease morbidity and hospital stay.

22 RADIATION REDUCTION IN PEDIATRIC CHEST CT: SUB-CENTIMETER LESION DETECTABILITY Kevin J. Roche, MD, Radiology, New York University Medical Center, New York, NY; Rafael Rivera, MD; Naomi Strubel, MD; Nancy R. Fefferman, MD; Lynne P. Pinkney, MD; Nancy B. Genieser, MD Purpose: To determine whether reduced MA for chest CTs affects the ability to detect and characterize subcentimeter pulmonary lesions in patients with malignant neoplasms. Materials and Methods: Non-contrast chest CT examinations, using both standard and more recently adopted lower mA settings, were retrospectively reviewed in twenty patients with known primary malignant neoplasms. Five examiners read a total of 40 studies each. Lesions were characterized in terms of number, location, size and the confidence that a lesion represented a metastsis (5=highly likely, 4=likely, 3=indeterminate, 2=unlikely, 1=highly unlikely). Study quality was graded as excellent, good, adequate, unacceptable. Surgical excision, response to treatment and/or six-month follow-up were performed for confirmation of radiographic findings. Results: The mean overall reduction in radiation dosage was 42 % (range 34–60 %). For patients less than 10 years old, radiation reduction was 56 % (range 41–60 %). For patients greater than 10 years-old, radiation reduction was 38 % (range 34–58 %). There was no statistically significant difference in terms of lesion detectabilty between standard and lower mA CT techniques (p > .05). Conclusion: Chest CT, using decreased mA techniques, resulted in a significant reduction in radiation dosage (mean 42 %) while the ability to detect sub-centimeter lesions was unchanged.

23 LOW CONTRAST LESION DETECTION AND RADIATION DOSE IN PEDIATRIC CT* Marta Hernanz-Schulman, MD; Mark Reese, MD, Radiology, Vanderbilt University Medical Center, Nashville, TN; Price Ron, MD; Pickens David, PhD; Stein M. Sharon, MD; Heller M. Richard, MD; et al Purpose: Determine relationship between mAs and low contrast lesion identification, and the effect of film vs. workstation on lesion detection. Methods: 16 cm low-contrast phantom, (13 lesions 0.3–2 cm) was imaged at 40–300 mAs (20 mAs increments, collimation: 3, 5, and

7 mm). Three pediatric radiologists, blinded to parameters, recorded number of lesions detected in each viewing format. Radiation dose was measured at phantom center; S/N and spatial resolution as a function of mAs. Vp was constant at 120. Results: Lesion detection increased with mAs, collimation, lesion size, and viewing on workstation vs. Film (W200–L40). Relative peak lesion detection on film occurred at 200 mAs: 3 mm: 1 lesion; 5 mm: 3.5; 7 mm: 5.5. On workstation this occurred at 160 mAs: 3 mm: 6; 5 mm: 10; 7 mm: 12; lesion detection was markedly increased. There was little improvement above 200 mAs. Lesion detection doubled at 100 mAs with 7 mm collimation; at 160 mAs with 5 and 3 mm collimation. S/N increased with mAs and collimation. At 3 mm S/N was less than 2 at all mAs levels, at 7 mm above 2 at 160 mAs. Radiation dose range was 320–3050 mrad at phantom center. Spatial resolution was constant at 7 lp/cm. Conclusion: At low contrast, mAs and radiation dose can be lowered effectively, and need to be considered in conjunction with collimation and viewing parameters, which significantly affect detection of diagnostic information.

24 IN-PLANE BISMUTH BREAST SHIELDS FOR PEDIATRIC CT: EVALUATION OF EFFECTS ON DOSE AND IMAGING QUALITY USING EXPERIMENTAL AND CLINICAL DATA* Bradley L. Fricke, MD, Radiology, Cincinnati Childrens Hospital, Cincinnait, OH; Lane F. Donnelly, MD; Donald P. Frush, MD; Terry Yoshizumi, PhD; Vladimir Varchena, PhD; Stacy A. Poe, MS; et al Purpose: To evaluate the degree of dose reduction and effect on image quality when using a bismuth in-plane breast shield for CT of the chest and abdomen in girls. Methods: 50 consecutive CT scans (chest 29, abdomen 21) (subjects: mean age 9 years, all female) were performed with a 2-ply (2 mm thickness, 1.7 gm bismuth/cm2) bismuth shield (three sizes for varying patient size) in place overlying the breasts. CT images were evaluated for a perceptible difference in image quality (yes, no) in the lungs at the anatomic level under the shield as compared to non-shielded lung and whether the images were of diagnostic quality (yes, no). In addition, 2 mm regions of interest were placed in the peripheral anterior and posterior portions of each lung in shielded and non-shielded areas and noise (stand deviation for HU) was measured. Differences in noise were compared for both individual anatomic areas (ie anterior left vs. anterior left) and all areas combined (all left and right, anterior and posterior) for shielded versus non-shielded areas (paired t-test). The breast shield was also evaluated with an infant anthropomorphic phantom (ATOM, CIRS) using thermoluminescent detectors at the breast tissue. The phantom was imaged with ant without the breast shield using identical CT parameters. The study was IRB approved. Results: All scans demonstrated diagnostic quality with no perceptible difference in image quality in shielded vs. non-shielded lung. There was no statistically significant difference between the shielded and non-shielded lung for noise for either all areas together (mean noise shielded 17.3, non-shielded 18.8, p ¼ 0.5180) or for any individual area (all p greater than 0.2). There was also no significant difference in noise comparing anterior to posterior values (mean noise anterior 18.4, posterior 18.7, p ¼ 0.2). Phantom measurements demonstrated a 30 % reduction in dose to the breast when using a medium-dose CT protocol. Conclusion: Bismuth in-plane breast shielding for pediatric CT decreased radiation dose to the breast by 30 % and demonstrated no qualitative or quantitative changes in image quality. Further studies with breast shields are ongoing. (Vladimir Varchena, PhD works for CIRS.)

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25 CT FINDINGS AND OUTCOME OF PERSISTENT PULMONARY INTERSTITIAL EMPHYSEMA IN NEONATES: A MULTI-INSTITUTIONAL STUDY Lane F. Donnelly, MD, Radiology, Cincinnati Children’s Hospital, Cincinnati, OH; Javier Lucaya, MD; Vanildo Ozelame, MD; Donald P. Frush, MD; Peter J. Strouse, MD; Thomas E. Sumner, MD Purpose: Pulmonary interstitial emphysema (PIE) typically resolves over time. Rarely, PIE may persist (PPIE), forming an expanding, lucent mass that can cause mass effect and progressive respiratory distress. The presence of soft tissue density linear and dot-like structures in the central of the lucent lesions seen on CT has been described as specific for PPIE (vessels surrounded by interstitial gas). In contrast to other types of lucent lung masses seen in neonates, the initial treatment of PPIE is non-surgical; therefore, CT findings separating PPIE from other lesions would be helpful. Since reports are limited, our purpose is to review CT features and outcome of infants with PPIE. Methods: From 6 institutions, 16 cases of PPIE who underwent CT were identified. All cases were neonates who required ventilation for lung disease and developed hyperexpanded lucent lung lesions following typical radiographic findings of PIE. CTs were reviewed for anatomic distribution, appearance, and presence of classic lines/ dots within lucent mass. The management (surgical vs. non-surgical) and outcome in non-surgical cases was recorded and compared between USA (8) and non-USA (8) cases. Results: On CT, all lesions were hyperexpanded, cystic lucencies. Distribution was single lobe 9 (LUL 5, LLL 3, RML 1), multilobar 7, and bilateral 5. 14 (88 %) of 16 cases demonstrated the characteristic lines/dots pattern. All cases were initially managed conservatively. 9 patients eventually underwent surgical resection with pathologic confirmation. Of 9 patients who underwent non-surgical management for a least a year, lesions resolved in 4, decreased in size in asymptomatic patients in 3, and enlarged eventually leading to resection in 2. Surgical resection was performed in 100 % (8/8) of USA cases as compared to 13 % (1/8) of non-USA cases. Conclusion: Most cases (88 %) of PPIE demonstrate characteristic CT findings (central lines/dots surrounded by lucency). PPIE occurred more frequently on the left than right. Although most cases in this series eventually underwent surgical management, initial management should be conservative. The decision to perform surgery may reflect the underlying medical culture.

26 DATA ANALYSIS OF 3D LUNG VOLUMES OF CHILDREN WITH ASPHYXIATING THORACIC DYSTROPHY UNDERGOING LATERAL THORACIC EXPANSION SURGERY Brent H. Adler, MD, Radiology, Children’s Hospital, Columbus, OH; Terrance Davis, MD; Robert Castile, MD; Richard Shel, MD; Fred Long, MD Method and Materials: Six children with ATD age 6 months to 18 months were evaluated for a new method of chest wall expansion. During the work-up children underwent Chest CT performed with a controlled ventilation technique. The CT was done using a single or multislice helical acquisition. CTs were repeated before the second side was expanded and after recovery. The 3D data set obtained was analyzed with respect to lung volume using established techniques. The lung volume was evaluated for regional density differences which might suggest localized emphysema, and to determine which areas of the lung were affected by the surgical expansion. Data was compared to standard Pulmonary Function Tests done the same day as the CT.

Results: The CT data sets demonstrated increases in lung volume that correlated well with the standard PFTs. They demonstrated increases in lung volume that correlated with clinical improvement. Regional differences were observed between upper and lower lobes but further investigation is needed to validate this technique.

27 LOW-TUBE CURRENT, MULTISLICE HELICAL CT FOR CHILDREN WITH SUSPECTED EXTRINSIC AIRWAY COMPRESSION* Preeyacha Pacharn, MD, Radiology, Cincinnati Children’s Hospital, Cincinnati, OH; Lane F. Donnelly, MD Objective: Because of rapid speed of acquisition, multislice helical CT is becoming a more widely used means of evaluating for extrinsic airway compression/vascular rings. In contrast to MRI in infants and young children, CT examinations can often be performed without sedation. The major disadvantage of CT, radiation exposure, can be minimized by using low tube current and rapid table speed. This study reviews the technical success and need for sedation when using low-tube current, multislice CT for the evaluation of children with suspected extrinsic airway compression. Materials and Methods: All CT examinations performed for evaluation of extrinsic airway compression during the first year after instillation of a multislice CT scanner at a pediatric hospital were reviewed. Technical parameters, including tube current, kVp, slice thickness, mode of study, sedation technique, amount of contrast material, and post processing techniques applied were recorded. Studies were evaluated for timing of contrast bolus, image quality, motion artifact, need for sedation, usefulness of reformatted images, and diagnoses made. Studies were reviewed by two pediatric radiologists and conclusions made by consensus. This review of data was approved by our IRB. Results: There were 54 studies performed in 50 patients (mean age 2.4 years, range 15 days–17 years, 30 male / 20 female). The mean tube current was 52.2 mA (range 30–140 mA). Thirty-four (63 %) studies were performed without sedation (sedation 12, general anesthesia 6, intubated prior to imaging 2). Imaging quality was excellent in 35 (65 %), diagnostic in 19 (35 %), and poor in none. Motion artifact was present on several slices of 2 (4 %) examinations. Contrast was well-timed in 49 (91 %), early in 3 (5 %), and late in 2 (4 %) examinations. Multiplanar or 3D reconstructions were created in 16 (30 %) and felt to be helpful in 4 cases. Airway abnormalities were detected in 26 (48 %) studies including extrinsic compression by vascular anomalies (14) or nonvascular masses (5), and intrinsic airway disease without extrinsic compression (7). Conclusions: Evaluation for extrinsic compression of the pediatric airway can be accomplished using a low-tube current, multislice CT protocol, without the use of sedation in the majority of cases. In our practice, multiplanar or 3D reconstructions were occasionally performed and offered unique information in a minority of studies.

28 COMPARISON OF UPPER AIRWAY MOTION AS DEPICTED ON CINE MR DURING SLEEP IN CHILDREN WITH AND WITHOUT OBSTRUCTIVE SLEEP APNEA Lane F. Donnelly, MD, Radiology, Cincinnati Children’s Hospital, Cincinnati, OH; Victoria Surdulescu, MD; Barbara A. Chini, MD; Keith A. Casper, MS; Stacy A. Poe, MS; Rauof S. Amin, MD Purpose: The degree of airway obstruction during sleep may not be directly related to intraluminal diameter of the upper airway. We hypothesize that children with obstructive sleep apnea have

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increased dynamic motion of the upper airway during sleep as compared to controls. The purpose of this study is to compare patterns of dynamic airway motion as depicted on MR cine studies during sleep between children with and without obstructive sleep apnea. Materials and Methods: Fast gradient echo images were obtained on a 1.5 T MR scanner in the sagittal midline to create MR cine images. MR cine images obtained during sleep were compared in 12 children with obstructive sleep apnea and 148 children with no airway symptomatology. Motion of the nasopharynx, oropharynx, and hypopharynx were characterized as static patent (SP), dynamic patent (DP), intermittent collapse (IC), or static collapsed (SC) and maximal diameter and greatest change in size (mm) were calculated. Adenoid size and mouth position (opened, closed) were determined. Differences in the frequency of imaging parameters in the different anatomic regions were evaluated (Chi Squared Test, Fisher’s Exact Test, Satterthwaite t-Test). In the apnea group, patterns of airway motion were also evaluated on axial MR cine images obtained at the level of the mid hypopharynx. Results: There were statistically significant differences in the two groups for the following parameters: nasopharynx SP (p ¼ 0.0002) and IC (p < 0.0001); hypopharynx SP (p ¼ 0.0006) and IC (p ¼ <0.0001); oropharynx IC (p ¼ 0.0205); and mean change in airway diameter in the nasopharynx (p ¼ 0.0012) and hypopharynx (p ¼ 0.0007). The mean adenoid size was larger for the OSA group (p ¼ 0.0280). On axial MR cine images, the mean change in diameter was greater in the left-to-right diameter (13.3 mm) than in the anterior-to-posterior diameter (10.1 mm). Conclusions: There are significant differences in the patterns of dynamic airway motion between children with and without obstructive sleep apnea. Evaluation of patterns of dynamic motion may provide valuable information that may not be available on static imaging. The axial plane may provide greater quantitative information when evaluating airway motion than the traditional sagittal plane.

29 RADIOLOGICAL/PATHOLOGICAL CORRELATION OF CONGENITAL LUNG MASSES IN INFANTS Soroosh Mahboubi, M.D., Radiology, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania; Anne Hubbard, M.D.; Eduardo Ruchelli, M.D.; Scott Adzick, M.D. Purpose: The purpose of this study was to correlate the accuracy of Spiral CT Scan of the Chest with Surgical Pathologic result of Congenital Lung masses in infants. Material and Methods: 34 infants (17 male and 17 female) age 1 day to 3 months (average 1.7 m) had CT Scan of the chest following administration of 2 cc/kg intravenous contrast media under sedation. All CT Scan results correlated to pathological results. Results: 18 of 34 patients with Cystic Adenomatoid Malformation (CCAM) pathology confirmed the CT Scan. CT Scan diagnosed 6 of 34 pathologically confirmed sequestration (SEQ). CT Scan diagnosed 5 of 6 pathologically confirmed combination of CCAM and SEQ. CT Scan correctly diagnosed 1 patient with both CCAM and Congenital Lobar Emphysema (CLE), 1 patient with CCAM and Bronchiogenic Cyst, 1 patient with CCAM and Bronchial Atresia and 1 patient with simple CLE. Conclusion: Congenital lung masses in infants have characteristic CT Scan features but there is a spectrum of combined lesions for which enhanced CT Scan is most helpful.

30 WIRELESS CAPSULE VIDEOENDOSCOPY: A NEW TECHNIQUE TO EVALUATE SMALL BOWEL DISORDERS – PRELIMINARY STUDY* Ana Maria Guilhon, MD; Jose´e Dubois, MD, Departments of Medical Imaging and Gastroenterology, Hopital Ste-Justine and Universite´ de Montre´al, Montreal, Quebec, Canada; MarieClaude Miron, MD; Ernest G. Seidman, MD Purpose: To evaluate the feasibility, the sensitivity and the specificity of the capsule videoendoscopy in children. Materials and Methods: A prospective study (October 2001– December 2001) was performed in pediatric patients (11 to 17 y.o.) suspected to have small bowel disorders such as: 1) Crohn disease; 2) polyposis; 3) occult GI bleeding. The Given Imaging diagnostic system is made of three main subsystems: an ingestible M2A capsule, a Given data recorder and a rapid workstation. We compared the results of the videocapsule procedure for each patient with the gold standard imaging procedure used to diagnose the disorder. Patients were followed for two weeks after the procedure in order to detect delayed adverse reaction. Results: We studied 8 patients (3F, 5M): 3 occult GI bleeding, 3 intestinal polyposis and 2 misleading Crohn disease. In the group of occult bleeding, the vascular anomaly was confirmed in 2 out of 3. In the group of polyposis (Peutz-Jeghers Syndrome) the capsule confirmed small bowel polyps in all 3 cases. Both patients with Crohn disease were observed to have typical aphtous and linear ulcers in the small bowel. All exams were well-tolerated and without adverse events. Conclusion: The videocapsule study is an improvement for the evaluation of the small bowel in children. It is safe, easy to perform and particularly useful for obscure small bowel disorders.

31 ULTRASOUND: STILL A RELIABLE METHOD FOR DIAGNOSING APPENDICITIS WITHOUT RADIATION – A 3-YEAR RETROSPECTIVE ANALYSIS Martha M. Munden, MD; E. B. Singleton Department of Diagnostic Imaging, Texas Children’s Hospital, Houston, TX; A. Dilley, MD; D. Wesson, MD; J. Hicks, MD Purpose: Recent publications have raised public concern regarding long term risks of radiation in the pediatric population. Our aim was to evaluate and revisit the usefulness of sonography in the routine management of children with suspected appendicitis in a large pediatric hospital. Materials and Methods: Results of 2056 ultrasound examinations performed on children and adolescents with suspected appendicitis over a 3 year period from August 1, 1996 to July 31, 1999 were cross referenced with surgical and pathology databases retrospectively. Results: Ultrasound examinations were performed for right lower quadrant pain or suspected appendicitis by staff radiologists or pediatric radiology fellows available 24 hours a day. Ultrasound examinations over this 3 year period had a sensitivity of 89 %, specificity of 95 %, positive predictive value of 86 %, and a negative predictive value of 96 % (true positives, n=496, false positives, n ¼ 81, true negatives, n=1417, false negatives, n=62). Pathology unrelated to appendicitis was found by ultrasound examination in 157 patients. Conclusion: In a setting where ultrasound examinations are performed routinely for right lower quadrant pain, sonography can be used to limit the use of radiation for evaluation of children with suspected appendicitis effectively.

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32 IS THE ADMINISTRATION OF ORAL CONTRAST SAFE PRIOR TO ABDOMINAL CT IN CHILDREN WHO REQUIRE SEDATION?* Matthew A. Ziegler; Bradley L. Fricke; Lane F. Donnelly, MD, Radiology, Cincinnati Children’s Hospital, Cincinnati, OH Objective: It has been common practice to administer oral contrast in preparation for abdominal CT in children who require sedation or general anesthesia in order to be examined. At some institutions, the practice of giving oral contrast prior to sedation / anesthesia is being challenged because it does violate NPO status that is otherwise strictly enforced prior to sedation. Our purpose is to review our safety record with administering oral contrast for CT prior to sedation. Materials and Methods: Radiology reports, medical records, and department incident reports were reviewed from all patients who required sedation for abdominal CT for the past five years (IRB approved). Patient age, gender, type of sedation given, and complications related to oral contrast prior to the sedation (defined as vomiting with aspiration) were recorded. For routine oral contrast, dilute hypaque was administered in an age based amount 1 hour prior to scanning. For sedation, depending upon patient age either oral choral hydrate (70–100 mg/kg) or IV pentobarbital (3 mg/kg with repeat dosing up to 7 mg/kg) was utilized. Results: 337 patients who received oral contrast prior to sedation for abdominal CT were identified (mean age 2.9 years, range 1 month–19 years, 200 boys, 167 girls). Chloral hydrate was utilized in 30 and IV pentobarbital in 337. No complications related to the administration of the oral contrast prior to the sedation were identified. Conclusions: The practice of administering oral contrast prior to sedation for abdominal CT in children is safe and should not be discontinued based on safety issues.

34 UPPER MOTILITY CATHETER PLACEMENT IN CHILDREN: A SIX YEAR EXPERIENCE* Anne Marie Cahill, M.D., Radiology, Children’s Hospital of Pittsburgh, Pittsburgh, PA; Carlo D. DiLorenzo, M.D.; Robin D. Kaye, M.D.; Richard B. Towbin, M.D.; Charles R. Fitz, M.D. Purpose: To discuss the technique, method of data acquisition, technical difficulties and results of upper motility catheter placement in children. Materials and Methods: From February 1995 to present 239 upper motility catheter procedures were performed fluoroscopically in 234 children (119 M, 115 F), age range 6 mths to 48 yrs, mean 10 yrs. The clinical indications include reflux/vomiting/retching (97), feeding intolerance (12), abdominal distension/pain (28), transplant evaluation pre/post (23), weight loss/food refusal (6), diarrhea/constipation (71), and miscellaneous (2). 213 catheters (90 %) were placed via the nares (90 %) and 24 catheters (10 %) via the preexisting G stoma site. The catheter tip was determined to be in ideal position when 2 transducer sideports were located in the gastric antrum and 6 in the duodenum. Results: 237 upper motility catheters were successfully placed without sedation. There were 2 failed catheter placements due to difficult access post small bowel transplant. 5 patients had followup studies. 184 (77 %) of the studies demonstrated abnormal antroduondenal motility, 45 (20 %) were normal, and 8 (3 %) results are pending at present. There were no complications. Conclusions: Upper motility catheter studies provide significant diagnostic information in cases of bowel dysmotility. The technique, technical limitations and data acquisition are discussed in this presentation.

35 LOWER MOTILITY CATHETER PLACEMENT IN CHILDREN: A SIX YEAR EXPERIENCE* 33 SHOULD CT REPLACE BARIUM FOR IBD EVALUATION*? Peter J. Shipman, MBBS, Radiology, Gastroenterology, BC’s Children’s Hospital, Vancouver, B.C., Canada; Douglas H. Jamieson, MBChB; Kevan Jacobson, MBChB; David M. Israel, MD Purpose: Comparison of SBFT with multidetector CT evaluation of IBD. Methods: This is an ongoing prospective study. 10 patients undergoing initial workup for IBD underwent endoscopy, SBFT and CT prior to commencement of therapy. The CT protocol was a multislice portal venous phase study. Examinations were independently reviewed. Patients completed questionnaires assessing each study. Results: In 8/10 cases CT and SBFT concurred in evaluation of terminal ileal (TI) disease. In 2 cases the TI was not visualized in SBFT but CT demonstrated TI disease. In 2 cases CT detected skip segments of small bowel disease not appreciated by SBFT. In no instance did SBFT show disease not demonstrated on CT.CT provided additional information in 8 cases, including extent of colonic involvement in 7 cases (2 with incomplete colonoscopy), and one colonic juvenile polyposis.The questionaire revealed 9/10 patients preferred CT. The reasons were poor tolerance of barium and long duration of SBFT. Conclusion: CT involves increased radiation, but has better sensitivity for small bowel IBD compared to SBFT.CT consistently allows evaluation of the entire small and large bowel and in 4/10 patients this was not achieved with combined SBFT and colonoscopy.

Anne Marie Cahill, M.D., Radiology, Children’s Hospital of Pittsburgh, Pittsburgh, PA; Carlo D. DiLorenzo, M.D.; Robin D. Kaye, M.D.; Richard B. Towbin, M.D.; Charles R. Fitz, M.D. Purpose: To discuss the technique, data requisition, and technical difficulties of colonic motility catheter placement in children. Materials and Methods: From February 1996 to present 225 colonic motility catheter procedures were performed in 225 children (117 M, 108 F), age range 1.5 yrs to 12 yrs, mean 11 yrs. All children were sedated with a combination of Pentobarbitol, Fentanyl and Midazolam intravenously. The clinical indications include constipation/encopresis (99), abdominal pain (4), diarrhea (9), transplant evaluation (2), evaluate for possible stoma closure (3), and closure of ileostomy (1). The lower motility catheter placement was deemed appropriate if the tip was positioned at least in the left hemicolon and at least one transducer sideport in the rectum. Ideal location of catheter comprised the tip positioned in the right hemicolon with the most proximal transducer sideport in the rectum. Results: 224 lower motility catheters were successfully placed with endoscopic and fluoroscopic guidance. One procedure failed due to rectal perforation with endoscope. 122 studies demonstrated abnormal colonic motility, 96 were normal studies and 6 results are pending. Conclusion: Lower motility catheter placement is a useful diagnostic tool for colonic dysmotility. The radiologic technique, difficulties in catheter placement, data acquisition and results are discussed in this presentation.

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36 PLAIN FILMS IN INTUSSUSCEPTION: AN ANALYSIS OF FINDINGS*

38 TRANSIENT SMALL BOWEL INTUSSUSCEPTION IN CHILDREN ON CT

Jose A. Hernandez, MD, Radiology, The University of Texas Medical Branch, Galveston, Texas; Leonard E. Swischuk, MD; Eric P. Hendrick, MD; Carlos A. Angel, MD

Peter J. Strouse, MD, University of Michigan, Ann Arbor, MI; Michael A. DiPietro, MD; Fermin Saez, MD

Purpose: To review and document the plain film findings in cases of proven intussusception and assess their relative frequency and importance. Materials and Methods: We conducted a retrospective review of 74 patients with proven intussusception documenting the following abdominal radiological findings: normal gas pattern, high grade obstruction, early or partial obstruction mass, rim sign, paucity of right lower quadrant gas, and combination of: (1) mass, obstruction and paucity of lower quadrant gas, (2) obstruction and mass, and (3) mass and normal small bowel. Results: A normal gas pattern was found in nearly 50 % of cases. The next most common finding was high grade obstruction. Partial obstruction was seen in 23 % of cases and a mass was seen in 25 % of cases. An obstruction and a mass were seen in 7 % of cases, while a mass with a normal small bowel gas pattern was seen in 16 % of cases. the classic triad of obstruction, mass and paucity of gas in the right lower quadrant was not seen in any of our patients. Conclusions: Plain films in intussusception are extremely variable and a normal film is very common. This would suggest that the plain film is not very reliable for the detection of intussusception if a mass or obstruction are not present.

37 THE EFFECT OF SCREENING SONOGRAPHY ON THE POSITIVE RATE OF ENEMAS FOR INTUSSUSCEPTION* Susan Henrikson, BS; Caroline E. Blane, MD; Khaldoun Koujok, MD; Peter J. Strouse, MD; Michael A. DiPietro, MD; Mitchell M. Goodsitt, PHd Purpose: To determine the change in rate of positive enemas performed for suspected intussusception with the intervention of screening ultrasound. Methods and Materials: Since October 1995, 221 patients (mean age 2.2 years) with suspected intussusception were referred for enema. In January 2001 ultrasound (US) was introduced as a screening test for intussusception. Enemas were performed after a positive US and were offered for negative US if clinical suspicion persisted. Results: Prior to 2001, 184 children underwent enema with intussusception documented in 40 (22 %). Since January 2001, 37 children have been sent with suspected intussusception. Four went directly to enema (1/4 positive). 33 children had an US. In 15/33 the US was positive and intussusception was found at enema in 14/15. In 18 cases the US was negative. Four of the 18 children with a negative US had an enema, which was also negative. 14 enemas were canceled. The positive rate for enemas prior to screening US was 22 % and since January 2001 in those cases without US the positive rate was 25 %. With a screening US the positive rate for enemas is 74 %. We know of no case of intussusception missed on US. Conclusion: Screening US has dramatically decreased unnecessary enemas for clinically suspected intussusception. This has in turn reduced radiation exposure to our patients.

Objective: To determine the significance of small bowel intussusception in children on CT. Materials and Methods: CT reports between 1995 and 2001 were reviewed to identify patients with small bowel intussusception. Intussusceptions were identified as an intraluminal mass with a characteristic layered appearance and/or continuity with adjacent mesenteric fat. Ileocolic intussusceptions were excluded. Imaging studies and medical records were reviewed. Results: 21 pediatric patients (15 male, 6 female; mean age ¼ 11.8 years) were identified with small bowel intussusception on CT. No patient had a persistent intussusception requiring surgery. Seven had immediate repeat CT images as part of the same examination demonstrating resolution of the abnormality. In two patients with persistent symptoms, underlying pathology was subsequently identified requiring treatment (giardiasis – 1, small bowel inflammation/strictures – 1). In 19 other patients, direct correlation of symptoms to CT abnormality was absent or questionable, no treatment was required, and there was to clinical or imaging evidence of persistence or recurrence. Follow-up CT (n ¼ 10 (4 within 24 hours)), ultrasound (n ¼ 1) and small bowel follow-through (n ¼ 4) showed no abnormality. Conclusion: Most small bowel intussusceptions identified in children by CT are transient and of no clinical significance.

39 EXTRA-URINARY FINDINGS IN CHILDREN WHO ARE REFERRED FOR RENAL-BLADDER US WITH SIGNS AND SYMPTOMS LIMITED TO THE URINARY TRACT: WHAT IS THE YIELD IN ALSO IMAGING THE ENTIRE ABDOMEN AND PELVIS?* Mamata Chithriki, MD; J. Michael Zerin, MD, Department of Pediatric Imaging, Children’s Hospital of Michigan, Detroit, MI Purpose: Children who are referred to us for renal-bladder US also undergo examination of the abdomen and pelvis, even when they only present with urinary signs and symptoms. This project was undertaken to determine the frequency of non-urinary US findings in these patients. Materials and Methods: We retrospectively reviewed dictations from renal-bladder/abdominal ultrasound examinations in 773 consecutive pediatric patients with urinary symptoms. UTI was the most common indication. Other indications included hypertension, antenatal hydronephrosis, incontinence, reflux, hematuria, and proteinuria. Patients with signs or symptoms of non-urinary intraabdominal disease were excluded. Results: Urinary tract abnormalities were detected in 274 patients (35.4 %). Sixty-four (8.3 %) had non-urinary abnormalities. Unsuspected, clinically important non-urinary abnormalities were detected in 10 (1.3 %) – asplenia (n=1), choledochal cyst (n=1), and gallstones (n=8). In three patients, extra-urinary sonographic ‘‘abnormalities’’ were either not confirmed or had resolved on later imaging – gallbladder ‘‘mass’’ not identified on repeat pre-cholecystectomy US (n=1), abdominal aortic ‘‘flap’’ not present on MRI or aortography (n=1), and ‘‘absent’’ uterus and ovaries clearly identified on later MRI (n=1). Conclusion: Unsuspected, clinically important non-urinary abnormalities are very uncommon in children who present for urinary tract US and have no signs or symptoms suggestive of extra-urinary disease.

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40 ULTRASOUND CONTROL OF BONE REGENERATION DURING MANDIBLE COMPRESSION-DISTRACTION OSTEOSYNTHESIS IN CHILDREN* Andrei G. Nadtotchi, MD, PhD, Radiological, The Moscow State Medical & Stomatological University, Moscow, Russian Federation; Natalia I. Bojarina, MD; Sergei A. Ulianov, PhD, MD Purpose: Mandibular compression-distraction osteosynthesis (MCDO) is a modern surgery-sparing lengthening method for mandibular abnormalities and acquired deformities. This presentation will show the value of ultrasound (US) as a guide for MCDO. Materials and Methods: 25 children (13–18 years old) with unilateral (19) and bilateral (6) distraction were examined by dynamic US (SonoDiagnost-360, Philips) at the time of bone fragment compression, each week during the distraction, and once per 2–3 weeks during the fixation stage. Results: US showed uncomplicated MCDO in 17 patients. In 4 cases, unusual osteogenic activity was recognized; 2 cases showed high osteogenesic activity (increased distraction rate); and 2 cases with low osteogenesic activity (decreased distraction rate). The use of ultrasound after MCDO correction showed no complications in 21 patients. In 4 cases MCDO complications were shown: 1 case of osteoporosis development; 1 case with mandible angular deformation (compression-distraction device (CDD) had been in incorrect position); 1 case with a CDD metallic construction deformation; and 1 case with the regenerating bone partially ruptured. Conclusions: Dynamic US is very useful in each stage of MCDO. The correction of CDO may be satisfactorily evaluated thanks to US.

41 BLADDER MALKOPLAKIA Aruna Vade, MD; Brian Steele, MD, Radiology, Loyola University Medical Center, Maywood, IL; Jennifer Lim-Dunham, MD We report imaging features of bladder malkoplakia in a 16-yearold girl with Russell-Silver Syndrome who presented with a syncopal episode. Routine evaluation revealed chronic renal insufficiency and urine leukocytosis. Work-up of the patient’s renal disease included renal ultrasound, lasix renal scan, voiding cystourethrogram, and retrograde pyelogram. It is important that the radiologist be aware of the sonographic appearance of bladder malkoplakia (not described before in the literature) since ultrasound is often the first imaging modality requested for the evaluation of urinary tract infection. This presenter will discuss or describe a medical device that is classified by the FDA as investigational for the intended use.

42 MR DIFFUSION IMAGING OF KIDNEYS IN CHILDREN Damien Grattan-Smith, MBBS, Children’s Healthcare of Atlanta at Scottish Rite, Emory University School of Medicine, Atlanta, Ga; Richard A. Jones, PhD; Stephen Little, MD; Marcos Perez, MD; Andrew Kirsch, MD Purpose: To evaluate the role of MR diffusion imaging in the kidneys of children. Materials and Methods: Diffusion imaging of the kidneys has been performed in six children without evidence of renal disease and in three children with hydronephrosis. The diffusion technique used a single shot EPI with a diffusion trace preparation sequence, three b values were obtained and respiratory gating was used to obtain consistent positioning. ADC maps were calculated for all six slices. In the children with hydronephrosis the diffusion scans were acquired

prior to the administration of Lasix and ten to fifteen images were acquired at one minute intervals after injection. ADC was evaluated in regions of interest placed in the renal cortex and medulla. Results: Normal children have symmetric ADC values and values measured in older children are consistent with those previously reported with the ADC in the cortex being typically 25 % higher than that of the medulla. There appears to be an age dependent variation in the ADC values. To date little change in the ADC values following the administration of Lasix has been observed. Conclusion: Diffusion imaging of the kidneys is a method that has the potential to evaluate individual renal function.

43 MR IMAGING OF KIDNEYS: FUNCTIONAL EVALUATION USING F-15 PERFUSION IMAGING Damien Grattan-Smith, MBBS, Children’s Healthcare of Atlanta at Scottish Rite, Emory University School of Medicine, Atlanta; Richard A. Jones, PhD; Stephen Little, MD; Marcos Perez, MD; Andrew Kirsch, MD Purpose: To evaluate functional imaging of kidneys using a F-15 perfusion imaging protocol in children with hydronephrosis. Materials and Methods: 33 scans have been performed in 31children with hydronephrosis using F-15 perfusion imaging technique (mean age 1.6 years). Fifteen minutes after administration of Lasix a 3D, T1 weighted gradient echo set of images was obtained prior to an injection of contrast agent (Gd-DTPA). Subsequently the 3D sequence was repeated every 15 seconds for 3 minutes and then at one minute intervals up to a total of twenty minutes. Signal intensity versus time curves were generated. To determine the split renal function the volume of perfused renal parenchyma is calculated at two minutes. Results: There were 14 children with UPJ obstruction, 5 with UVJ obstruction, 8 duplex systems, and 4 showed no evidence of obstruction. Two children were studied both pre and post-operatively. The anatomic delineation of the urinary tract was superior to other imaging techniques. Differential renal function was comparable in most cases to the differential renal function as determined by renal scintigraphy. Conclusion: F-15 Perfusion imaging is a technique that combines excellent morphologic imaging with the ability to calculate differential renal function and to evaluate renal excretion.

44 TRANSURETHRAL SUBURETERIC INJECTION OF AUTOLOGOUS CHONDROCYTES FOR TREATMENT OF VESICOURETERAL REFLUX: SONOGRAPHIC IMAGING FEATURES* Bharti Khurana, MD; Harriet J. Paltiel, MD, Children’s Hospital Boston, MA; David A. Diamond, MD; David Zurakowski, Ph.D; Anthony Atala, MD Purpose: To determine the US features indicative of success or failure of transurethral subureteric injection of autologous chondrocytes, a novel, minimally invasive alternative to conventional operative repair of vesicoureteral reflux. Materials and Methods: Fifty-eight injections of autologous chondrocytes were performed in 40 ureters. Treatment success was determined by normal post-procedure voiding cystography. The presence of hydroureteronephrosis, and the presence, volume, contour, and echogenicity of the subureteric cartilaginous mounds were assessed by US done 1 month, 1, 2 and 3 years after treatment. Correlation with treatment success was performed using the Fisher exact test. Results: Reflux was successfully treated in 24/58 injections. Chondrocyte volume and US mound volume were weakly correlated

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(r=0.29, p=0.04). In 8/58 no mounds were identified by US and the failure rate was 100 %. In 3/58 the mounds were bifid and the failure rate was 100 %. In the remaining 47 injections, there was no correlation between mound volume, echogenicity and treatment success. Transient moderate hydroureteronephrosis developed in one child. Conclusion: Ultrasound mound volume and echogenicity are indeterminate features with regard to treatment outcome. Absence of chondrocyte mounds or presence of a bifid mound contour by US has 100 % correlation with treatment failure. Treatment-induced hydroureteronephrosis is rare. This presenter will discuss or describe a medical device that is classified by the FDA as investigational for the intended use.

45 TESTICULAR TORSION IN THE PEDIATRIC PATIENT: SONOGRAPHIC APPEARANCE OF THE EPIDIDYMIS Anna R. Blask, MD, Radiology Department, Children’s National Medical Center. George Washington University, Washington, DC; Gil Rushton, MD Purpose: To determine the sonographic appearance of the epididymis in pediatric patients with testicular torsion. Materials and Methods: The sonographic studies of 30 patients [newborn-17 years] with testicular torsion were reviewed. The size and appearance of the epididymis, color flow, surgical/pathologic findings, and outcome were assessed. Results: There were 8 patients with acute torsion and 22 patients with late phase torsion. The testis was salvaged in 6/8 patients with acute torsion and in none of the patients with late phase torsion. The epididymis was enlarged in all patients [range 1.5 cm x 1.3 cm x 1.5 cm–5.5 cm x 4 cm x 4.5 cm]. The epididymis was avacular in 26/30 cases, hypovascular in 1/30 cases, hyperemic in 2/30 cases, and hyperemic in 1/30 cases studied only post detorsion. 3/3 cases studied after detorsion showed epididymal flow. The epididymis was heterogeneous or homogeneous with increased echogenicity. Pathologic examination showed hemorrhagic infarction. Conclusion: An enlarged hyperechoic epididymis is a consistent finding and can resemble an extratesticular mass. In the majority of cases (93 %), the avascular or hypovascular appearance at color Doppler distinguishes the epididymis from epididymitis. However, infrequently (7 %) the epididymis can be enlarged and hyperemic. The appearance of the epididymis is abnormal in both acute and late phase torsion and cannot be utilized to predict testicular salvage.

46 OVARIAN TORSION: INITIAL DIAGNOSIS ON ABDOMINAL AND PELVIC CT* Peter I. Maslin, DO, Dept. of Radiology, Winthrop University Hospital, Mineola, NY; Adam M. Gittleman, MD; Anita P. Price, MD; Dan Barlev, MD; Thomas H. Smith, MD; Douglas S. Katz, MD Ovarian torsion is an uncommon surgical emergency which is often confused clinically with other conditions in both pre- and postmenarchal girls. Although sonography remains the imaging test of choice for this disorder, with the increasing utilization of CT for imaging children with acute abdominal and pelvic conditions, ovarian torsion may now be initially encountered on CT. We present the CT findings in three girls who were diagnosed with ovarian torsion on the basis of an abdominal and pelvic CT scan. The CT appearance of ovarian torsion is highly specific, and is very similar to its sonographic appearance of an enlarged ovary with multiple peripheral follicles.

47 PRECOCIOUS PSEUDOPUBERTY WITH SYMMETRICAL OVARIES: US FINDINGS AND EVOLUTION Francoise Rypens, MD; Laurent Garel, MD, Department of Medical Imaging, Hopital Ste-Justine and Universite de Montreal, Montreal, Quebec, Canada; Josee Dubois, MD; Andree Grignon, MD; Guy Van Vliet, MD Usually, isosexual precocious pseudopuberty (PPP) is associated with a stimulated uterus and unilateral follicular cyst whereas symmetrical ovaries are detected in central precocious puberty (CPP). Purpose: To report cases of PPP associated with symmetrical ovaries and their peculiar evolution. Patients and Methods: The clinical, biological, and imaging data of 13 girls with isosexual PPP were retrospectively reviewed and correlated with the follow-up (1988 to 2001). Eight patients with unilateral ovarian cyst were excluded from the study. Results: 5 patients had symmetrical ovaries and presented with breast development and vaginal bleeding at a mean age of 2 y. and 7 m.o. (16 m.o. to 3 y. 11 m.o.) Bone age was normal (n=4) or slightly increased (n=1). Pelvic US detected stimulated uterus (n=5) with symmetrical normal ovaries (n=2), or symmetrically enlarged ovaries with multiple large follicles (n=3). 3 patients had McCune-Albright syndrome with polyostotic fibrous bone dysplasia and slowly progressing pubertal development. Uterus remained stimulated on follow-up. 2 patients had only ‘‘cafe´-au-lait’’ spots without further pubertal development. Conclusion: PPP may present sonographically with symmetrical ovaries (5/13 in our material). A stimulated uterus and symmetrical ovaries in a patient with sexual precocity is therefore not synonymous of CPP.

48 CHILDREN’S EMOTIONAL STRESS DURING RADIOLOGIC PROCEDURES: IS IT THEIR TEMPERAMENT OR THE TEST? Dunya T. Yaldoo, PhD; Marilyn J. Goske, MD, Pediatric Radiology, Cleveland Clinic Children’s Hospital, Cleveland, Ohio; Jonathon Ross, MD; Stuart Morrison, MD; Janet R. Reid, MD; Sunny Chung, MD; et al Purpose: Little investigation into the impact of radiologic testing on a child’s emotional well-being has been performed. General competency goals (‘‘practice based improvement’’) set by the American Board of Radiology suggest patient feedback after testing. This study compares the emotional and behavioral morbidity experienced by children undergoing voiding cystourethrogram (VCUG) with the less invasive renal ultrasound (US). Materials and Methods: Twenty-four children (1–8 yrs, 18 girls, 6 boys) have been studied. Parents complete the Child Behavior Checklist (CBCL) and Colorado Childhood Temperament Inventory (CCTI) prior to procedures. After imaging, radiologists (PDR) and parents (PPQ) rate their perceptions of child distress. Two weeks later, parents complete follow-up CBCL and PPQ. Results: Marginal evidence was found of a potential negative relationship between Sociability and radiologist PDR (Spearman correlation, r=)0.40, p=0.08) and of a potential positive relationship between Emotionality and level of distress experienced during catheter insertion (Spearman correlation, r=0.43, p=0.11). A marginally significant increase (+1.78) in aggressive behavior post-VCUG was found (Wilcoxon signed-rank test, p=0.06). Conclusion: To date, findings suggest that level of distress experienced during VCUG may correlate with temperament. There may be short-term increase in aggressive behavior post-VCUG.

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48A FAST MR IMAGING OF SMALL CELL TUMORS IN CHILDREN, NCI PROPOSAL

49 TRANSCRANIAL DOPPLER (TCD) CHANGES IN CHILDREN WITH SICKLE CELL DISEASE (SSD) ON HYPERTRANSFUSION THERAPY: WHAT SHOULD WE EXPECT?* Wendy Thomas, MD, MPH, Diagnostic Imaging, Children’s National Medical Center, Washington, DC; Dorothy Bulas, MD; Catherine Driscoll, MD; Caterina Minnitti, MD; Gilbert Vezina, MD Purpose: To evaluate changes in TCD velocities in SSD patients undergoing hypertransfusion therapy.M & M: Since 1998, 34 SSD patients have been treated with hypertransfusion therapy. 16 children (mean 10.1 yrs) had 2 or more TCDs (ATL, HDI 5000) performed while on therapy (32 studies on, 14 off therapy). Changes between sequential studies were classified as increased, decreased, or unchanged within normal (<170 cm/sec), conditional, or abnormal (>200 cm/sec) categories. 26 comparisons were categorized and correlated with MRA findings. Results: 6 children with normal MRAs s/p stroke had normal TCDs while on hypertransfusion. Of 3 studies following discontinuation of therapy, 1 demonstrated a mild increase in velocities but remained < 170 cm/sec.Of 10 children with abnormal MRAs, all TCDs initially were abnormal. 7 follow up studies remained unchanged on therapy. 7 studies demonstrated a decrease in velocities, though 6 remained in the abnormal/conditional range. Of 3 patients with abnormally low velocities secondary to severe stenosis, 2 increased to conditional range on therapy, while 1 developed LMCA occlusion on therapy. Conclusions: TCD velocities alter slightly once on transfusion therapy. Abnormally high velocities may decrease on therapy but typically remain in abnormal/conditional range. Abnormally low velocities may increase on therapy. Patients with normal MRAs and TCDs remain normal on therapy.

50 OPTIMIZATION OF CRANIAL CT IMAGES WHILE LOWERING THE RADIATION DOSE Thomas L. Slovis, MD, Pediatric Imaging, Children’s Hospital of Michigan, Detroit, MI; Thomas L. Toth, MS; Stanley Fox, PhD; Wilbur Smith, MD Purpose: A single cranial CT in children (0–17 y) has a CT Dose Index (CTDI) between 1.5–4.5 cGy. Many children receive multiple CTs. Attempts at lowering the radiation by decreasing the mA result in reduced tissue contrast (gray-white interface) and produced more noise. Decreasing kV theoretically increases mA will keep will keep the noise constant and lower radiation. We attempted to lower radiation while keeping the ratio of tissue contrast to noise constant. Materials and Methods: Thirty children who received multiple cranial CTs were evaluated at 80 and 120 kV. Half had a third scan at 100 kV. The mA was increased by a factor of 2.8 so that the CTDI was approximately the same as the initial scan of 120 kV. The raw data was then electronically manipulated by adding noise to simulate lowering the mA. Images were created and compared with the initial scan for gray white differentiation and noise. Results: The preliminary findings showed that decreasing kV with the same radiation dose produced images with higher tissue contrast. This suggests we can maintain current image quality and lower the radiation dose by 20–30 %. (Technical support from General Electric Medical Systems.)

51 INCIDENCE OF SUBDURAL HEMORRHAGE BY MR IN TERM NEONATES WITH CONGENITAL HEART DISEASE UNDERGOING VAGINAL DELIVERY Robert A. Zimmerman, M.D., Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Federica Tavani, M.D.; William S. Mahle, M.D.; Robert R. Clancy, M.D. Purpose: To determine the incidence of subdural bleeding in normal vaginal delivery of term infants without complicated births. Materials and Methods: Twenty-four infants with congenital heart disease were examined by MRI in the days after birth but before corrective heart surgery. Twenty-one patients had uncomplicated vaginal deliveries with Apgar scores at 1 minute of 7 or above and at 5 minutes of 8 or above. Results: Twelve of 21 had subdural hemorrhage posteriorly at the tentorium or along the falx. Seven had choroid plexus hemorrhage (CPH) and one with a CPH had blood in the occipital horn. The 3 patients born by Caesarean delivery were free of any bleeds. Conclusion: Normal vaginal deliveries produce some tentorialposterior falx subdural bleeding in more than 50 % of cases.

52 REVERSIBLE POSTERIOR LEUKOENCEPHALOPATHY IN CHILDREN: CLINICAL UTILITY OF PROTON MR SPECTROSCOPY Kim M. Cecil, PhD, Children’s Hospital Medical Center Cincinnati, OH; Richard S. Dunn, RT; Blaise V. Jones, MD Purpose: To demonstrate the MR spectroscopy (MRS) findings in reversible posterior leukoencephalopathy (RPL) in children, and show how these findings are consistent with the proposed etiology of these lesions. Reversible posterior leukoencephalopathy describes a condition demonstrating focal lesions arising from hypertension or toxicity following treatment with therapeutic agents such as cyclosporine. However, discriminating these lesions from other conditions such as infarction, metastatic disease, and demyelination can be difficult. Methods: MR Spectroscopy was employed in distinguishing RPL from other disease processes in 12 children. Results: Children with a benign MRS profile of lesions, without choline and lactate elevations, demonstrated resolution of symptoms and lesions in followup examinations. Children with lactate elevations on MRS demonstrated volume loss and/or leukomalacia on followup. Conclusions: MRS is useful in the clinical evaluation of RPL in children. MRS can confirm the diagnosis of RPL over other disease etiologies. Furthermore, MRS can demonstrate the character of these lesions and distinguish them as either reversible or irreversible ischemic foci. These are significant differential considerations in the immunocompromised pediatric population.

53 MRI OF CHIARI MALFORMATION COMPLICATIONS IN PEDIATRIC PATIENTS: INFARCTIONS AND CONTUSIONS WITH FALLS Robert A. Zimmerman, M.D., Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Federica Tavani, M.D.; A. Telfeian; Larissa T. Bilaniuk, M.D.; Erin M. Simon, M.D. Purpose: To demonstrate that Chiari malformations can present as an acute neurological problem following trauma.

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Materials and Methods: Six pediatric patients, age 11 months– 18 years, 3 male and 3 female, were studied by MRI acutely following falls. Results: Three patients demonstrated cerebellar infarctions related to vascular compression of the vertebral artery by the caudalized cerebellar tonsil; while in the other patients, tonsillar contusions were present. Conclusion: Chiari malformation constitutes a risk factor for posterior fossa infarction and contusion following falls in pediatric patients.

54 PERINATAL MRI OF TERMINAL MYELOCYSTOCELES

of the spinal nerve sheath. All but 2 children had scoliosis. In 4 boys, the neurofibromas were solitary; 2 dumb-bell, 1 intradural and 1 paraspinal tumor(s). Three boys had plexiform neurofibromas of the sacral plexus. Solitary lesions were resected in 2 children because of its intradural component. Follow up imaging performed for 6 children over a mean follow up period of 59 months showed no evidence of tumor progression or recurrence. Conclusion: There have been very few published reports of systematic radiologic screening for NF-1 children, especially of the spine. We found that intracranial lesions (excluding UBO) are rare whilst spinal tumors are not uncommon in our population. These findings have important implications on the optimal strategy for radiologic screening in NF-1 children.

Larissa T. Bilaniuk, MD, Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA; Erin M. Simon, MD; Robert A. Zimmerman, MD; Leslie N. Sutton, MD; Scott Adzick, MD

56 MAPPING AGE-RELATED CHANGES IN DTI VALUES IN THE BRAINS OF NORMAL CHILDREN

Purpose: To present fetal MRI characteristics of terminal myelocystoceles, which constitute a rare form of skin-covered dysraphism in the lumbosacral region. Also, to demonstrate how these lesions can be differentiated from the more common myelomeningoceles. Material and Methods: Four fetuses were diagnosed with ultrafast MRI to have terminal myelocystoceles. One fetus had serial followup MRI studies. There was no elevation of amniotic alpha fetoprotein and acetylcholinestarase in any of the cases. Results: All four fetuses were noted to have large sacs with relatively thick walls and with prolapsed stretched cord coursing through the sac. There were no hydrocephalus or Chiari II changes. Serial follow-up in one fetus showed progressive marked enlargement of the sac. In one fetus the sac ruptured. Conclusion: Terminal myelocystocele can be differentiated from myelomeningocele on fetal MRI and this is of great importance because only myelomeningoceles are considered for fetal surgery.

55 THE CLINICAL UTILITY OF RADIOLOGIC SCREENING IN ASYMPTOMATIC NEUROFIBROMATOSIS-1 (NF-1)* Pek-Lan Khong, MD, Department of Diagnostic Radiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong; Winnie Goh, MD; Virginia Wong, MD; Cheuk-Wing Fung, MD; Clara Ooi, MD Purpose: The optimal strategy for radiologic screening in NF-1 children is controversial and unresolved. We describe the findings and evaluate the clinical utility of a MRI screening program in Chinese children with NF-1. Materials and Methods: Sixty-two children, consecutively seen in a NF-1 clinic between July 1995 and Jun 2001 were recruited into a screening program, which included MR imaging of the brain, orbit and spine. All children were asymptomatic and satisfied the clinical criteria for diagnosis of NF-1. MR imaging of the brain and orbit (n=55) and spine (n=53) was performed using a 1.5T imager. MR imaging findings, clinical signs and symptoms and subsequent clinical management were recorded. Results: MRI brain and orbit: Thirty-seven patients (67.3 %) had T2-weighted hyperintensities (UBO) in the brain. Other findings were Moya Moya disease in 2 patients (3.6 %), optic gliomas (5mm and 6 mm in size) in 2 patients (3.6 %) and dysplastic cerebellum and arachnoid cyst in 1 patient each. Apart from 1 patient with an optic glioma who had decreased visual evoked potential amplitude in the affected eye, other patients had no neurological signs referable to the lesions. All lesions were treated conservatively. Fortyone follow up MR scans available in 23 patients over a follow up period of 36 months did not demonstrate progression of lesions. MRI spine: Seven children (13.2 %), all boys, had neurofibromas

John C. Haselgrove, PhD, Department of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania; Erin M. Simon, MD, OTR; Joan Rubin, BA; Dongzhu Jin, MD Purpose: Quantitative evaluation of pediatric brain Diffusion Tensor Index (DTI) values powerfully detects abnormalities. We extend previous studies of normal values (1,2). Materials and Methods: We have accrued data on 34 children (16M, 18F; 3 mo–8 yrs) using a Siemens Vision 1.5T scanner with b values ¼ 0 and 800 sec/mm2 in 6 directions (15, 5 mm slices; gap 5 mm, FOV 240, MA=96*128, NEX=4). Apparent diffusion coefficient (ADC) and anisotropy index (AI) were calculated for 23 regions including corpus callosum, internal capsule, deep gray nuclei, lobar and cerebellar cortices and white matter, corona radiata, centrum semiovale, pons, and middle cerebellar peduncle. Results: ADC falls with age, while AI rises. ADC and AI variations with age fit a single decaying exponential model, asymptoting to a constant value (Value ¼ A exp(age/k) + C). In the corpus callosum, ADC almost halved and AI almost doubled from 3 months– 3 years. In many other white matter regions, brain maturation (represented by decay constant of anisotropy) was significantly longer than that of ADC. Conclusion: We provide whole brain DTI imaging normal values against which individual values may be compared. References: 1. P Mukherjee, et al. Radiology 221:349–358 (2001) 2. MC Morris, et al. Neuroradiology 41:929–934 (1990)

57 DIFFUSION IMAGING IN HERPES SIMPLEX VIRUS (HSV) INFECTION IN INFANTS AND CHILDREN Robert A. Zimmerman, M.D., Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Erin M. Simon, MD; Larissa T. Bilaniuk, MD Purpose: To evaluate the sensitivity of diffusion weighted imaging (DWI) relative to conventional MR with and without gadolinium in the identification of HSV infection in the brain. Materials and Methods: Four infants and 2 children with HSV infection were studied utilizing 1.5T MR with T1, T2, FLAIR, DWI and T1 + Gad enhancement. Results: Diffusion imaging was positive in two infants when routine imaging was still negative. Subsequent studies showed evolution of injury at sites positive on diffusion in these two patients as well as the four in which both diffusion and routine MRI were positive.

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Conclusion: DWI is a sensitive component of the MR evaluation in children suspected of HSV infection. Failure to utilize DWI may lead to failure to diagnose HSV by imaging.

60 CORRELATION OF TOTAL INTENSITY UPTAKE IN WHITE BLOOD CELLS SCINTIGRAPHY AND BIOLOGICAL PARAMETERS IN THE FOLLOW-UP OF CHILDREN WITH INFLAMMATORY BOWEL DISEASE*

58 TECHNICAL FAILURE RATE OF SINGLE VOXEL MAGNETIC RESONANCE SPECTROSCOPY IN PEDIATRIC BRAIN STUDIES

Jean-Louis Alberini, M.D.; Department of Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA; Martin Charron, M.D.; Fabio Ponzo, M.D.; Dan Von Allmen, M.D.

Tina Young Poussaint, MD, Radiology, Children’s Hospital, Boston, MA; Richard L. Robertson, MD; Francine M. Kim, MD; Karen M. Sarao, BA; Robert V. Mulkern, PhD Magnetic Resonance Spectroscopy (MRS) is useful for clinical diagnosis of numerous pediatric diseases including brain tumors, hypoxic-ischemic encephalopathy and various metabolic diseases. Modern 1.5 T scanners now come equipped with single voxel MRS capabilities which largely overcome early technical difficulties which often rendered MRS studies difficult to perform and interpret. We have determined how reliably our current MRS package (General Electric Medical Systems) yields diagnostically useful spectra. From November 2000 to November 2001, we performed 385 single voxel short echo STEAM (N ¼ 98) and long echo PRESS (N ¼ 287) MRS as part of the standard clinical brain MR exam for various brain disorders, particularly tumor. Technical failure was identified as the inability to properly phase, identify and quantify standard metabolite signals with manufacturer supplied software (SAGE) due to various combinations of poor water suppression and shim, noisy baselines, or excessive lipid contamination. Of the 385 spectra analyzed, a total of 27 were deemed of no diagnostic value due to technical failure. The 9.4 % failure rate over the course of one year’s recent clinical activity is considered encouraging from the perspective of utilizing MRS as a reliable clinical tool in this new millenium.

59 CODED APERTURES IN NUCLEAR MEDICINE: IMAGING A 19 lCi 57CO POINT SOURCE IN 1 SECOND WITH 1.7-MM RESOLUTION

Purpose: In order to evaluate the role of White Blood Cells Scintigraphy (WBCS) in the follow-up of children with Inflammatory Bowel Disease (IBD), we studied retrospectively the correlation between the evolution of the scan activity index (SAI), semiquantitative measure of the intensity uptake in involved segments, and of different biological parameters measured at two different times in the follow-up. Patients and Methods: Sequential 34 WBCS were performed in 17 children (age med ¼ 13.5y) with IBD. The evolution of SAI was correlated with these of erythrocyte sedimentation rate (ESR), WBC count (WBC) and platelets (PLAT) with 3 different patterns (improved, stable or worsed). Results: Decrease, stability and increase of SAI were respectively observed in 11, 3 and 3 patients. The evolution of biological parameters was as follow: respectively for ESR, WBC and PLAT improvement was noted in 9, 8 and 4 patients; stability was noted in 4, 7 and 11; a worsening was noted in 4, 2 and 2 patients. A correlation was obtained between SAI and ESR in 11 patients and was better than for WBC or PLAT. Conclusion: Stability of WBC and PLAT values was observed in the majority of the patients and represented a limitation for their use to quantify the intensity of the IBD. Correlation between SAI and ESR was good. WBCS using SAI seems to be a useful tool to evaluate the intensity of IBD, in association with ESR.

61 PEDIATRIC TRACHEOBRONCHOGRAPHY: INDICATIONS, TECHNIQUE AND RESULTS IN 254 DIAGNOSTIC AND INTERVENTIONAL PROCEDURES

Roberto Accorsi, Ph.D., Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Martin Charron, M.D.; Richard C. Lanza, Ph.D.

Derek J. Roebuck, FRANZCR; Clare McLaren, Radiology, Great Ormond Street Hospital, London, United Kingdom

Purpose: to demonstrate the potential for high sensitivity and high resolution of a nuclear medicine coded aperture camera. Methods and materials: a coded aperture is a particular arrangement of many pinholes (in our case 480). Having many pinholes increases sensitivity but comes at the price of having to deal with overlapped copies of the same image. The particularity of coded apertures is that this overlap can be conveniently undone by computer post-processing. Image reconstruction takes about 1 second on a commercial personal computer and recovers a single image from the collected data. We compared the performance of a 1-mm pinhole to a coded aperture with 1-mm pinholes arranged in a 62 x 62 pattern based on a Modified Uniformly Redundant Array. The detector was a commercial Anger camera. To compare sensitivity, a 19-lCi 57Co point source was imaged for different exposure times. For a fair comparison, resolution and field of view were the same for both the pinhole and the coded aperture. Results: both methods showed approx. 1.7-mm system resolution. The coded aperture showed a sensitivity higher than the pinhole by a factor of 480 and, unlike the pinhole, was capable of locating the point source after a 1-second exposure. Conclusion: coded apertures provide high-sensitivity imaging. This advantage can be exploited in terms of lower dose, higher resolution or decreased exposure times.

Purpose: To report the indications, technical aspects, and results for paediatric tracheobronchography. Materials and methods: Prospective study of tracheobronchography at a children’s hospital (August 1999 to December 2001). Indications, technique and outcome were recorded at the time of the procedure. Results: 254 tracheobronchograms were performed in 118 children. The age range was 7 days to 15 years (median 7 months). Indications for tracheobronchography included malacia in 151 (59 %) and/or stenosis in 136 (54 %). 172 tracheobronchograms (68 %) were purely diagnostic and 82 (32 %) were performed as part of an interventional procedure. All interventional and 87/172 diagnostic procedures (51 %) were performed under general anesthesia. Access to the airway was via an endotracheal tube in 194 (76 %), tracheostomy tube in 34 (13 %) and a laryngeal mask airway in 26 (10 %). Flexible bronchoscopy was performed in 115 (45 %). The most frequently-used contrast was iotrolan 240 (81 %). Dose range was 0.15 to 2.85 mL (median 0.75) for diagnostic and 0.20 to 5.65 mL (median 1.00) for interventional procedures. Interventions included stent insertion (24) and balloon dilation (63). There were no significant short-term complications (95 % confidence interval 0.0 to 1.2 %). 47 children (19 %) had transient arterial desaturation >10 %. Conclusion: Tracheobronchography is a safe procedure in children.

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62 DYNAMIC CONTRAST LYMPHANGIOGRAPHY FOR THE INVESTIGATION OF CHYLOUS LEAK IN CHILDREN*

64 COMPETENCY MAINTENANCE TRAINING SYSTEM FOR PEDIATRIC US GUIDED HIP ARTHROCENTESIS

David J. E. Lord, MBBS, Interventional Radiology, The Children’s Hospital, Harvard Medical School, Boston, MA; Steven K. Fishman, MD; Joseph Upton, MD; Loren J. Borud, MD; Patricia E. Burrows, MD

William E. Shiels, DO, Department of Radiology, Childrens Hospital, Columbus, OH; Brian D. Coley, MD; Mark J. Hogan, MD; James W. Murakami

Purpose: To investigate the efficacy of dynamic lymphangiography for investigation of chylous leaks. Materials and Methods: Records and imaging studies were reviewed in 10 patients who underwent lymphangiography (8 male, 2 female; age range 18 months–25 years; mean age 11.2 years; median age 10 years). Dynamic lymphangiography was performed by cannulation of inguinal lymphatic with a 30-gauge needle by a microsurgeon using an OR microscope. Contrast progression was monitored fluoroscopically until thoracic duct opacification, then by serial digital subtraction images and subsequent CT. Results: Indication for procedure was chylothorax in 8 patients, chyloperitoneum in 3 and chyluria in one. Seven patients had a known lymphatic anomaly, one had a lymphaticovenous anomaly and one patient with Noonan syndrome had chylothorax and lower body edema after cardiac surgery. Inguinal lymphatic cannulation was successful in 9/10 patients and appropriate anatomy imaged in 8/10. Dynamic lymphangiography delineated a discrete chylous leak in 7/10. The leak was confirmed at surgery in 6 patients who underwent lymphaticovenous anastomosis or surgical resection. In one patient the microsurgeon was unable to cannulate an inguinal lymphatic. Conclusion: Dynamic lymphangiography is feasible and reliable in demonstrating the precise site of chylous leaks.

63 EVALUATION OF CHILDREN WITH CONGENITAL HYPERINSULINISM WITH ARTERIAL STIMULATION AND HEPATIC AND PANCREATIC VENOUS SAMPLING Robin D. Kaye, M.D, Radiology, Children’s Hospital of Philadelphia, Philadelphia, PA; Paul S. Thornton, MD; Charles A. Stanley, MD; N. Scott Adzick, MD; Richard B. Towbin, MD Purpose: To demonstrate the techniques and results of transarterial stimulation and hepatic and transportal venous sampling for surgical planning. Materials and Methods: To date 31 patients with congenital hyperinsulinism have been studied. 25/31 patients failed medical therapy and required surgery. Preoperatively, under general anesthesia, angiography with selective arterial catheterization of the splenic, gastroduodenal, proximal SMA, and a control artery. In each of the vessels, calcium gluconate was injected and hepatic venous sampling performed at 30, 60, 90, and 120 seconds to detect insulin levels. In one patient, transhepatic pancreatic vein sampling (THPVS) was also performed, during which hypoglycemia was maintained and sampling from multiple veins draining the pancreas was performed to detect insulin levels. Results: Eighteen of 25 (72 %)had focal disease (FHI) and 7/25 had diffuse disease (DHI). Arterial stimulation and venous sampling (ASVS) was attempted in 17/18 patients with FHI and was successfully performed in 16/17. Fourteen out of 16 (88 %) had positive ASVS results that were informative about the site of the lesion. Six out of 7 patients with DHI underwent ASVS successfully. Results of the ASVS were consistant with DHI in 3 patients (50 %) but incorrectly suggested FHI in 3. Results of the THPVS incorrectly suggested FHI.

Purpose: To describe a lifelong learning and competency maintenance system for pediatric US guided hip arthrocentesis. Methods and Materials: A hip effusion/arthrocentesis tissue learning system was used for annual competency maintenance training in a group of 14 pediatric radiologists, to support a requirement that all members maintain competency for this on-call procedure. After training, group competency was analyzed in a group of 60 patients (mean age 64 months) with 66 attempted hip arthrocenteses. Results: The group succeeded in 94 % of first operator attempts at arthrocentesis. Individual training yielded a conversion from 30 % to 100 % success in pediatric hip arthrocentesis.

65 VENOUS ANATOMICAL VARIANTS DISCOVERED DURING PERCUTANEOUS EMBOLIZATION OF LEFT VARICOCELES Laurent Garel, MD, Departments of Medical Imaging and Surgery, Hopital Ste-Justine and Universite de Montreal, Montreal, Quebec, Canada; Josee Dubois, MD; Francoise Rypens, MD; Alain Ouimet, MD; Salam Yazbeck, MD Purpose: To report on the high incidence of anatomical variants of the origin, and the course of internal spermatic vein (ISV) discovered at the time of percutaneous embolization of left varicoceles in a pediatric population. Materials and Methods: We reviewed retrospectively the 65 cases of left varicocele treated by percutaneous embolization (grade II and III) in our institution between 1990 and 2000. The course of the left renal vein (LRV), the origin of the ISV, the number of ISV and their pathway were recorded in all cases, according to Ba¨hren classification. Results: In 37/65 (56 %), the ISV was single and arose from a normal LRV (type 1).The following variants were encountered: type 5 - circumaortic LRV 9/65 (14 %); type 4B - intrarenal origin of ISV 8/65 (12 %); type 2 - multiple ISV 5/65 (8 %); pelvic collaterals 6/65 (9 %). Conclusion: 1) Venous anatomical variants are frequently encountered (44 %) at the time of left varicocele embolization in children. 2) Such variants often impose some adjustments to the technique of embolization, and at time hamper the procedure.

66 INTRAARTICULAR STEROID INJECTIONS IN SMALL FOOT JOINTS OF PATIENTS WITH JRA: TECHNIQUES AND OUTCOMES William E. Shiels II, DO, Department of Radiology, Childrens Hospital, Columbus, Ohio; Robert R. Rennebohm, MD; Mark J. Hogan, MD; Brian D. Coley, MD; James W. Murakami, MD Purpose: To evaluate outcomes of US guided small foot joint steroid injection therapy (USGSI). Materials and Methods: 31 small foot joints in 11 JRA patients were treated with USGSI. Success and complications were evaluated with a mean follow-up time of 13. 5 months. Results: Subjective and objective improvement were documented in 97 % and 100 % of evaluated patients respectively. Treatment complications included only a single case of subcutaneous atrophy associated with steroid injection of a subtalar joint. A joint specific,

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weight-based steroid prescription table was used for treatment planning and execution. USGSI is now used in large and small joints, including elbow, wrist, ankle, tenosynovia, and bursae.

69 TRANSJUGULAR LIVER BIOPSY AND HEPATIC ARTERY EMBOLIZATION IN A FOUR-WEEK-OLD BOY WITH STAGE 4S NEUROBLASTOMA AND LIFE-THREATENING HEPATOMEGALY

67 CHILDHOOD TAKAYASU ARTERITIS

Derek J. Roebuck, FRANZCR, Department of Radiology, Great Ormond Street Hospital, London, United Kingdom; Antony J. Michalski; Peppy Brock

Philip Stanley, M.D., Imaging Services, Childrens Hospital Los Angeles, Los Angeles, CA; Derek Roebuck, MD; Ashley Barboza, MD Purpose: To review the clinical and angiographic features of children with Takayasu Arteritis seen at our institution. Materials and Methods: The angiographic features in 21 children, age 7 months to 14 years, were reviewed. There were 14 girls and 7 boys. Hypertension, diminished pulses, claudication and abdominal bruit were the most common presenting features. All patients had catheter angiography of the abdominal aorta and thoracic arch angiography was performed in nine patients. The presence or absence of each of five radiographic findings (occlusion, focal stenosis, diffuse irregularity or narrowing, poststenotic dilatation and aneurysm) were recorded for each artery and arterial system. Ten patients had repeat angiography. Results: Seventy-one abnormal systems were identified. Thirteen children had abnormalities confined to the abdomen with aortic and iliac artery narrowing (13), stenosis of the renal (26), celiac axis (3) and superior mesenteric arteries (7). Eight patients had irregular dilation or frank aneurysms of the thoracic aorta with stenosis and aneurysms of the carotid (11), subclavian (7) and brachiocephalic vessels (4).Treatment included bypass grafting, angioplasty, nephrectomy, antihypertensive and immunosuppressive therapy. Conclusion: Arterial narrowing and aneurysms of major vessels are common manifestations of Takayasu Arteritis. There are multiple therapeutic options with good results.

68 TRANSHEPATIC TRANSBILIARY BILE DUCT BIOPSY Michael J. Temple, MD, Diagnostic Imaging, Centre for Image Guided Therapy, Hospital for Sick Children, Toronto, ON, Canada; Peter G. Chait, MB, Ch.B.; Bairbre L. Connolly, MB, Ch.B. Purpose: To describe a unique approach to bile duct biopsy. Materials and Methods: Bile duct biopsy was performed in 2 male patients (9 & 10 yrs) using a transhepatic route after obtaining access to the biliary system. Indications for biopsy was biliary stricture of unknown cause resulting in biliary obstruction. One patient had undergone bone marrow transplants for acute myelogenous leukaemia. Both patients demonstrated tight focal stenosis of the proximal, intrahepatic common hepatic duct. Bile duct biopsy and biliary drainage was requested. Access was obtained via the right (n=1) or left (n=1) hepatic duct. The biliary system was delineated with contrast. A Neff set was used to introduce a 17 gauge coaxial needle into the area of biliary stenosis. Two samples were obtained with a 21 gauge X 2.2 cm Bard biopsy device. The area of stenosis was sampled by controlling respirations to result in an appropriate trajectory. Ultrasound was used to assure blood vessels were avoided. Following biopsy a biliary drain was placed. Results: There were no complications associated with the procedures. The samples obtained yielded bile duct. Histologic analysis demonstrated fibrosis in 1 and fungal hyphae in the other. Conclusions: Transhepatic transbiliary biopsy can be considered when both bile duct biopsy and biliary drainage are needed. This represents a unique and easily performed method of bile duct biopsy.

Infants with stage 4S neuroblastoma and rapidly-progressive hepatomegaly have a poor prognosis, due to respiratory and/or renal complications. A neonate with respiratory failure, IVC obstruction, coagulopathy and thrombocytopenia underwent transjugular liver biopsy (TJLB), Hickman catheter insertion, and hepatic artery embolization with PVA particles. There was biochemical evidence of tumor lysis (day 1) and stabilization of liver size (day 2). Systemic chemotherapy and external beam radiotherapy were given. The biopsy showed neuroblastoma with MYCN amplification. Fifteen months later he is well. Embolization is a promising option in stage 4S neuroblastoma with rapidly-progressive hepatomegaly. TJLB is feasible in neonates with liver tumors.

70 PEDIATRIC IMAGING PROCEDURAL SEDATION: EVALUATION OF A SYSTEMS APPROACH James H. Hertzog, MD; Kathleen K. Bradford, MD; Jodi Schirling; Leslie E. Grissom, MD, Departments of Anesthesiology and Critical Care and of Medical Imaging, A.I. duPont Hospital for Children and the Nemours Office of Operational Assessment, Wilmington, DE; Marc S. Keller, MD; Stephen L. Lawless, MD Purpose: Limited information about procedural sedation exists describing relationship of risk factors, medications, procedure type, and complications. Our approach uses sedation RNs and MD oversight (but not necessarily presence) with protocol patient assessment and medication administration. We analyzed data to understand better the aforementioned relationships. Materials and Methods: Since 1993, information has been collected prospectively including demographic and procedural data, personnel involved, co-morbidities, medication doses, medical and systems complications, and resultant therapies. Results: 5602 imaging sedations were performed representing 59.2 % of all procedural sedations. Other sedations included 2063 EEG (21.8 %), 1074 GI endoscopies (11.4 %), 377 ASR/BAER (4.0 %), and 336 LP (3.6 %). Medication doses were within recommended ranges for 90 % of sedations. Complication rates in pediatric imaging were 4.0 % medical, 2.0 % systems vs. EEG - 4.3 %, 4.3 %, GI 3.2 %, 2.2 %, ASR/BAER - 4.0 %, 4.0 %, and LP - 3.6 %, 3.6 %. Complications correlated with an increasing number of co-morbidities (p<0.05) and an increasing number of sedation agents(p<0.05). Conclusion: Using a systems approach to sedation, low complication rates were achieved and lowered with experience over time. Complications were associated with identifiable risk factors. Physician presence during the entire course of sedation may not be necessary.

71 N1177 (PH50), A LOW OSMOLAR NANOPARTICULATE IODINATED CONTRAST AGENT FOR CARDIOVASCULAR AND GENERAL CT APPLICATIONS Francis G. Blankenberg, MD, Lucile Salter Packard Children’s Hospital, Palo Alto, CA; Frandics Chan, MD, PhD; Reinhard Koenig, MD Purpose: N1177 (Photogen; New Hope, PA) is a suspension of crystalline triiodobenzoate, chemically similar to Hypaque

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(diatrizoate). N1177 has a very long circulatory half with little diffusion outside the vascular space. It is also taken up by macrophages in the liver and spleen. We wished to determine whether N1177 could be used as a blood pool and liver/spleen CT contrast agent. Methods: 6 Adult male New Zealand White Rabbits received intravenous injections of either 1 (n=2), 3 (n=2) or 6 (n=2) mL/kg of N1177;150mg/mL (76 mg/mL iodine) and underwent serial axial whole body images in the electron beam CT scanner (Seimens; 3mm collimation, 0.2 sec scan time) pre, immediate, 1, 5, 10, 15, and 20 minutes after the end of injection. Results: The half life of N1177 in the blood pool was 5, 10, and > 20 minutes (zero order clearance kinetics) in the 1, 3, and 6 mL/kg animals, respectively, with peak enhancements of 113.7, 208, and 291, HUs. Liver progressively enhanced with time in all groups with maximal attenuations of 112., 165, and 177.4 HUs at 20 minutes after injection, respectively. There was no renal or hepatobiliary excretion noted. Conclusions: N1177 can be used as both a blood pool liver contrast agent with permitting high resolution low radiation dose CT imaging protocols free of both mixing and perfusion artifacts without the need for power injection or strict timing. (Francis G. Blankenberg – Photogen Scientific Advisory Boar, Frandics Chan – Photogen Scientific Advisory Board, Reinhard Keonig – Photogen, Medical Officer.)

72 COMPARISON OF MR TECHNIQUES FOR DETERMINING THE INTRAABDOMINAL/SUBCUTANEOUS ADIPOSE TISSUE RATIO FOR PREDICTING CARDIOVASCULAR RISK IN CHILDREN: A PHANTOM STUDY Lane F. Donnelly, MD, Radiology, Cincinnati Children’s Hospital, Cincinnati, OH; Bernard J. Dardzinski, PhD; Kendall J. O Brien; Scott K. Holland, PhD; Stephen R. Daniels, MD Purpose: Patients who have a greater distribution of intraabdominal adipose tissue (IAT) as compared to subcutaneous adipose tissue (SAT) [increased IAT/SAT ratio] are at greater increased risk for coronary artery disease and diabetes. Such risk factors may develop in childhood. As pediatric obesity becomes an increasing health issue in the USA, it is likely that more research will be focused in this area. Previous investigations have used T1-weighted MR images to determine IAT/SAT ratios. There has been little investigation into the accuracy of different MR sequences in predicting adipose distribution. Other sequences are much faster and may prove more valuable for patient screening. The purpose of this investigation is to compare MR imaging and segmentation techniques in measuring IAT/SAT ratios using an adiposity phantom. Methods: A phantom was created to simulate the distribution of subcutaneous and intraabdominal fat: actual volumes: IAT ¼ 137 ml, SAT ¼ 690 ml, IAT/SAT ratio ¼ .199. Axial MR images were obtained twice through the phantom at 5 mm slice thickness, zero gap: T1-weighted SE images, T1-weighted fast Dixon images (images allow information segmented into water, fat, and combined images), T1-weighted 3D fast gradient echo (GRE), and T1-weighted 3D spoiled gradient echo (SPGR). An in-house computer software program was then utilized to segment the volumes of fat and calculate: total fat, IAT, SAT, and IAT/SAT ratios. Each imaging data set was segmented three times for a total of 6 sets of data for each imaging technique. Results: The imaging sequences performed as follows [mean result ( % actual volume)]: T1-weighted SE images: IAT ¼ 85.3 (62 %), SAT ¼ 597 (87 %), IAT/SAT ratio ¼ .142; fast Dixon fat images: IAT ¼ 95.5 (70 %), SAT ¼ 654 (95 %), IAT/SAT ratio ¼ .146; 3D GRE images: IAT ¼ 74.1 (54 %), SAT ¼ 528 (77 %), IAT/SAT ratio ¼ .138, 3D SPGR images: IAT ¼ 86.7 (63 %), SAT ¼ 583 (85 %), IAT/SAT ratio ¼ .149. All imaging sequences were insensitive to the small volumes of fat(narrow IV tubing) with the

fast Dixon being most accurate: fast Dixon 6.8 (18.3 %), T1weighted SE .47 (01 %), others 00 %. This is why the percentages are less for the IAT, which contained the tubing. Conclusion: Of the imaging sequences tested, the fast Dixon images, which segment data into fat and water data sets, was most accurate at predicting all volumes of fat. However, many of the imaging sequences performed equally well in predicting the IAT/SAT ratio, suggesting that a rapid imaging sequence may be adequate for predicting this ratio. Conventional T1-weighted SE images, the current sequence of practice for measuring visceral adiposity, may not be the optimal choice of MR sequences.This research is funded by the NIH.

73 FREE-BREATHING CARDIOVASCULAR MR IMAGING WITH REAL-TIME NAVIGATOR RESPIRATORY SYNCHRONIZATION IN PEDIATRIC PATIENTS AND ADULTS WITH COMPLEX CONGENITAL HEART DISEASES Taylor Chung, M.D.; Edward B Singleton Dept of Diagnostic Imaging, Texas Children’s Hospital, Houston, TX; Raja Muthupillai, PhD; Ricardo H. Pignatelli, MD; John P. Kovalchin, MD; Giles W. Vick III, MD Background: Respiratory motion causes artifacts in cardiovascular MR (CMR) examinations. Real-time respiratory navigator (NAV) technique which continuously tracks the diaphragmatic position has been used for adult coronary artery imaging successfully. Purpose: To evaluate NAV method for CMR in pediatric patients and adults with complex congenital heart diseases. Methods: In 2001, 28 pediatric patients (median age: 11 years; range: 3 months to 16 years) and 2 adults (23 and 25 years) underwent 34 CMR studies which include 3D fast spoiled gradient recalled echo with NAV. Reasons for CMR: exercise-induced syncope (n ¼ 18); Kawasaki disease (n ¼ 3); tetralogy of Fallot (n =2); pulmonary atresia (n ¼ 2); atrial septal defect/partial anomalous pulmonary venous return (n ¼ 2); transposition, coarctation, total anomalous pulmonary venous return. Correlations made with available echocardiograms, cineangiograms, and surgical data. Results: NAV technique provided superior delineation of proximal coronary arteries, proximal pulmonary arteries and veins, atrial septum, compared to other pulse sequences used. 29 of 34 cases had excellent correlation with clinical data. One case of false positive aberrant coronary artery on CMR was noted. Four cases had no correlations. Conclusions: NAV technique is feasible in free-breathing pediatric patients and it is not limited to coronary artery imaging.

74 FAST CINE MR EVALUATION OF LEFT VENTRICULAR FUNCTION IN PEDIATRIC PATIENTS USING BALANCED FASTFIELD-ECHO (bFFE) SEQUENCE WITH SENSIVITIY ENCODING (SENSE) ACCELERATION TECHNIQUE WITH INTERACTIVE REAL-TIME PLAN SCAN: WORK-IN-PROGRESS Taylor Chung, M.D., Edward B Singleton, Dept of Diagnostic Imaging, Texas Children’s Hospital, Houston, TX; Raja Muthupillai, PhD; Giles W. Vick III, MD; Ricardo H. Pignatelli, MD Purpose: To illustrate feasibility of a rapid MR examination of left ventricular function in pediatric patients. Methods: On a clinical 1.5T MR scanner, we used interactive realtime plan scan tool (to obtain the short axis plane of left ventricle (LV)), and 2D cine bFFE sequence with SENSE acceleration, to achieve 33 milliseconds temporal resolution evaluation of LV function. Both breath-holding (higher spatial resolution) and free-breathing (lower spatial resolution) examinations were

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performed in 4 patients (ages: 9, 10, 11, 15 years) with dilated cardiomyopathy (n ¼ 2) and muscular dystrophy (n ¼ 2). Breathhold duration per location was 4 seconds. LV was covered in 10 locations. Free-breathing scan time for the entire LV was 25 to 34 seconds (acquisition time per images ¼ 2 heart beats). LV ejection fraction (LVEF) was computed with both breath-hold and freebreath data by manually tracing LV endocardial margin on enddiastolic and end-systolic images. Results: Total scan time of entire examination ranged from 18 to 21 minutes. All patients could comfortably perform the breath-hold sequence. LVEF from breath-holding sequences and free-breathing sequences for the 4 patients respectively were: 23 % vs 27 %, 52 % vs 56 %, 63 % vs 55 %, and 28 % vs 24 %. Conclusions: A rapid MR measurement of LVEF in pediatric patients is clinically feasible using multiple 4-seconds breathholds or free-breathing technique.

75 ARE THE CLASSIC VASCULAR RINGS THE MOST COMMONLY ENCOUNTERED CAUSE OF EXTRINSIC COMPRESSION OF THE LOWER AIRWAY IN CHILDREN? Robert J. Fleck, MD and Lane F. Donnelly, MD, Department of Radiology, Cincinnati Children’s Hospital, Cincinnati, OH. Purpose: The literature describing the potential causes of extrinsic airway compression has emphasized classic causes of compression such as double aortic arch and pulmonary sling. The purpose of this study is to evaluate a large series of MRIs obtained on children with potential extrinsic airway compression to determine how often the cause of airway compression is from ‘‘classic’’ as compared to ‘‘other’’ causes. Methods: All MRI of the airway obtained over a 5-year period to exclude extrinsic airway compression were reviewed and positive cases identified. Extrinsic airway compression was categorized as secondary to ‘‘classic’’ causes when a double aortic arch, other arch anomaly with complete ring (right arch with aberrant left subclavian artery), or pulmonary sling. All other causes of compressed airway were considered ‘‘other’’. Results: 180 MRI was evaluated (mean age 1.6 years). Extrinsic airway compression was present in 67 (37 %) of the cases. Of those 67 cases, classic causes of airway compression were present in 13 (19 %) cases: double aortic arch 3, right arch with aberrant subclavian artery 7, pulmonary sling 3. ‘‘other’’ causes were the cause of airway compression in 54 (81 %) of cases: innominate artery compression syndrome 24, midline descending aorta 8, enlarged pulmonary arteries 7, chest wall deformity 5, post-operative anatomy 3, shift from hypoplastic lung 3, enlarged left atrium 2, and non-vascular middle mediastinal masses 2. Conclusion: Classic vascular rings are the cause of extrinsic airway compression in the minority of children (19 %) referred for imaging of extrinsic airway compression. This should be considered when teaching residents or evaluating imaging studies.

76 MAGNETIC RESONANCE ANGIOGRAPHY (MRA) OF THE TORSO AND CORONARY ARTERIES IN INFANTS WITH ACUTE PRESENTATION OF KAWASAKI DISEASE Taylor Chung, M.D., Edward B Singleton Dept of Diagnostic Imaging, Texas Children’s Hospital, Houston, Texas; Richard M. Braverman, MD; Wesley W. Vick III, MD; Ricardo H. Pignetelli, MD; Grace C. Kung, MD; Maria D. Perez, MD; et al Purpose: To illustrate the utility of MRA of the torso including the coronary arteries in the clinical evaluation of infants with Kawasaki disease.

Methods: Three infants (age range: 3–6 months) were imaged with clinical MR 1.5T scanner using ‘time-resolved’ contrast-enhanced MRA of the torso with SENSE acceleration technique (n ¼ 6) and non-contrast coronary 3D-MRA with respiratory navigator technique (n ¼ 6). All patients were sedated and freely-breathing. Scan times for each CE-MRA acquisitions were 5–6 seconds (average: 8 acquisitions) and 6–8 minutes for each coronary MRA acquisition (average: 3 acquisitions). Results of coronary MRA were compared with echocardiography. Medical records were reviewed. Referring pediatric rheumatologists were consulted to determine the clinical utility of the MRA results. Results: All MRA’s were successfully acquired and were of diagnostic quality. All 3 infants had multiple aneurysms in the arterial system torso and limbs. Coronary MRA revealed aneurysms in all infants and correlated well echocardiographic results. Serial MRA’s in 2 infants showed regression of aneurysms. MRA results helped to guide therapy in all cases. Conclusion: MR was used successfully as a non-invasive imaging modality to evaluate infants with Kawasaki disease yielding clinical relevant information to help guide therapy.

77 WITHDRAWN 78 CONSTRICTIVE PERICARDITIS IN A PEDIATRIC PATIENT: MRI EVALUATION WITH REVIEW OF CURRENT LITERATURE Bernard F. Laya, D.O.; The Children’s Medical Center, Dayton, OH; Lubabatu Abdurrahman, MD Constrictive pericarditis is uncommon in children. We report a case of an eight-year-old caucaisan boy who presented with chronic cough, dyspnea and orthopnea. Chest radiograph and echocardiogram revealed pericardial and bilateral pleural effusion. Cardiac MRI was obtained showing pericardial thickening and effusion with restriction in diastole. Dilated inferior vena cava was also noted. Constrictive pericarditis was suggested and the diagnosis was supported by the hemodynamic data obtained during cardiac catheterization. The patient underwent pericardiectomy and the symptoms damatically improved. The MRI characteristics of constrictive pericarditis are reviewed, along with brief discussion of other imaging modalities, pathophysiology and current concepts.

79 BONE MINERAL DENSITY (BMD) AND OSTEONECROSIS IN SURVIVORS OF CHILDHOOD ALLOGENEIC BONE MARROW TRANSPLANTATION (BMT) Sue C. Kaste, DO, Diagnostic Imaging, St. Jude Children’s Research Hospital, Memphis, TN; Tami Shidler, RN; Xiong Ton, PhD; Deo K. Srivastava, PhD; Greg Hale, MD; Richard Rochester, PA-C; et al Purpose: The growing population of pediatric bone marrow transplant (BMT) survivors is at risk for disease- and therapyinduced diminished bone mineral density (BMD) and osteonecrosis. Materials and Methods: With IRB approval, we retrospectively captured patient demographics, treatment history, MR (hips and knees) and BMD (QCT and DEXA) results of consecutive survivors treated and followed by us. Results: We studied 62 patients; 29 male; 47 Caucasian; 8 AfricanAmerican; 7 of other race. Median age at BMT was 10.9 y (range, 1.6 y to 20.4 y). Both QCT and DEXA were done in 43 patients,

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DEXA alone for 45, QCT alone for 52. Median time from BMT was 4.9 y (range, 0.9 y to 10.2 y). Median QCT-determined BMD z-score was )0.96 (range, )4.06 to 3.05) and for DEXA, )1.1 (range, )3.9 to 3.6). Estimated mean (SE) of BMD by QCT was )0.23 (1.53) for males and )1.39 (1.47) for females (P=0.0075). Age at BMT, race, primary diagnosis did not significantly correlate with BMD. Of 56 patients with MRs, 28 had evidence of osteonecrosis. Nineteen (68 %) were female; female risk of osteonecrosis was significant (p=0.0182; odds ratio 3.8 [95 % CI: 1.25–11.5]). Conclusions: Pediatric BMT survivors have decreased BMD and increased risk for osteonecrosis. They should be monitored for early onset osteoporosis and osteonecrosis.

per exam. Actual differences are likely greater, as patients scanned with clips at the base tended to have more complex disease than did the comparison outpatients. Conclusions: The addition of dynamic clip imaging decreased mean procedure time by 25 % and improved patient throughput. Radiologists subjectively reported needing less time to review exams with dynamic imaging. This was confirmed in 4 out of 5 faculty. Mean time for physician review and frequency of re-scanning has not significantly changed. The institution presenting this paper has indicated that it is a luminary site for ACUSON.

82 SPEECH RECOGNITION SOFTWARE: EFFECTS ON REPORTING TIME FOR PEDIATRIC SONOGRAPHY 80 THE EFFECTS OF USING VARIOUS SIZE MEASUREMENT METHODS IN TUMOR RESPONSE CATEGORIZATION Simon C. Kao, M.D., Radiology, University of Iowa College of Medicine, Iowa City, IA; Wyatt L. Hadley, B.A. Purpose: To show how the use of different measurement methods affect tumor response categorizations on follow-up imaging. Materials and Methods: Size measurements of pediatric abdominal tumors were obtained from 24 children (93 sets of CT) who had one or more follow-ups with residual tumor. For each patient, maximal orthogonal diameters and the craniocaudal extent were recorded. For each of the 69 follow-up examinations, the tumor response was classified by comparing 3D (including) vs. 2D (ignoring craniocaudal extent) methods, square vs. oblique axes of tumor, and the WHO (World Health Organization) criteria vs. RECIST (Response Evaluation Criteria In Solid Tumors). Results: Tumor response categorization by 2D versus 3D craniocaudal dimension differed by 13.9 %. Using square versus obliqueaxis yielded a different tumor response classification in 7.5 % of the time. The RECIST yielded a different tumor response classification from the WHO criteria in 6.8 % (4.6 % more responsive and 2.2 % less responsive) of the time. Conclusions: In tumor imaging, it is important to be consistent in the measurement method in follow-up of tumor size, including number and orientation of longest dimensions used. The newly proposed RECIST criteria may be used provided that all three orthogonal dimensions are taken into consideration.

81 EFFECT OF DYNAMIC CLIP REVIEW ON ULTRASOUND WORKFLOW Sara M. O’Hara, MD, Radiology, Children’s Hospital Medical Center, Cincinnati, OH; Diane S. Babcock, MD; Tracey Adams, RDMS Purpose: To assess the impact on time spent performing and interpreting sonographic exams, after incorporating dynamic clip review into routine protocols. Materials and Methods: Time studies were compared for the period just prior to initiation of dynamic imaging review and several months after. A separate study of Radiologist review time and scanning habits was performed without the faculty’s knowledge. Radiologists’ performance at the hospital base was compared with satellite centers where dynamic imaging was not accessible. Results: Mean procedure time decreased from 52 minutes (±36) to 39 minutes (±18) after adding dynamic clips; statistical significance p<0.01.Radiologists reported less frequently re-scanning patients, though the re-scan rate was not significantly changed, 15–16 %. Four out of five Radiologists spent less time reviewing each case when clips were utilized. Differences were small : 0.4–2.4 minutes

Steven Don, MD, Mallinckrodt Institute of Radiology, Washington University, St. Louis, MO; Sonia R. Francis, BS, MT(ASCP); Charles F. Hildebolt, PhD, DDS Purpose: To determine if speech recognition software decreases the reporting times for pediatric sonographic examinations. Methods: Traditional dictation was compared with a PC-based, commercial, speech-recognition software. For a pediatric radiologist who used traditional-dictation, the time between examination completion and the signing of the report was recorded for a 5-month period. Following this and speech-recognition training, reporting time with the speech-recognition system was recorded for the same radiologist over a 7-month period. The reporting times with the two methods were tested for significant differences with a Shapiro-Wilk W test. Results: Times were recorded for 392 traditional and 463 speechrecognition dictations. Reporting time significantly decreased from 3.4 hours with traditional dictation to 0.8 hours with the speechrecognition system (p<0.0001). With the speech-recognition system, 231 of 463 (50 %) reports took 20 minutes or less compared with 3 of 392 (1 %) for traditional dictation. Only 111 of 463 (24 %) reports took greater than 1 hour with the speech-recognition system, with the majority (58) of these being portable cranial sonograms. In contrast, only 56 of 392 (14 %) examinations were reported in less than 1 hour with traditional dictation. Conclusion: Speech recognition software dramatically decreased reporting time for pediatric sonography. Real-time reporting is possible.

83 THE EFFECT OF COMPUTERIZED RADIOLOGY ORDER ENTRY ON WORKFLOW, EFFICIENCY, AND USER SATISFACTION AT A UNIVERSITY CHILDRENS HOSPITAL Eric J. Crotty, MB, BCh, Radiology, Children’s Hospital Medical Center, Cincinnati, OH; John M. Racadio, MD; Melissa L. Rickey, RN; Brian R. Jacobs, MD Purpose: Aim 1: Effect of a Radiology Order Entry System (ROES) on efficiency of a radiology department. Aim 2: Impact of ROES on number of correctly written radiology orders. Aim 3: Effect of ROES on user satisfaction with radiology reporting. Materials and Methods: Aim 1: Time-motion study evaluated efficiency of a radiology department in providing written reports. Requisitions were prospectively followed from time of ordering to availability of final report, also noting times of various intermediate steps. In Aim 2, requisitions were evaluated for: date and time of request, contact physician name and number, type of study, indication, and medical history. Aim 3: physicians, radiologists, and radiology technicians completed questionnaires assessing their satisfaction with completed requisitions. Aims were studied before and after implementation of ROES.

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Results: Aim1: 27 requisitions examined. Mean time from order of study to availability of final report was 10hrs. Aim 2: 481 requisitions. <1 % of requisitions were complete. A commonly absent element was contact physician number (11.23 %). Aim 3: Overall satisfaction of clinicians, radiologists, and technologists with handwritten system was: ‘‘adequate’’ to ‘‘good’’. Results post-implementation of ROES will be presented at meeting.

84 IMPLEMENTING DIGITAL DOCUMENTS TO SUPPLEMENT SOFT COPY FILM INTERPRETATION. ACCURACY AND REPRODUCIBILITY OF BONE AGE DETERMINATIONS USING TRADITIONAL AND SOFT COPY TECHNIQUES Brent H. Adler, MD, Radiology, Children’s Hospital, Columbus, Ohio; Larry Binkovitz, MD; D. G. Bates, MD Purpose: To create and evaluate an online bone age atlas, using an existing standard text. Demonstrate the creation, distribution, use and reliablity of a digital documents to supplement PACs and softcopy film interpretation. Method: Permission was sought and granted to digitize the images of Gruelich and Pyle’s atlas of skeletal developement. The Online version was created with an off the shelf Digital Camera and off the shelf digital document creation programs. It is viewed on the PACs workstation with programs loaded by the PACs vendor for use with other documents. Three radiologists prospectively reviewed the bone ages of 50 girls using Hard Copy film and the standard text, Soft Copy film and the standard text, and Soft Copy film and online text. Intra and Interobserver variability was calculated. Results: The three radiologists had good agreement on bone age with less than one age standard variability using any of the techniques. There was less than one age standard variability between their own standard readings and the various soft copy techniques. The document was easily mastered and well accepted. It has become the method of choice for determining bone age in our department since migration to soft copy image interpretation.

85 EFFECTIVE TEACHING IN A DIGITAL AGE: RESIDENTS EVALUATE A WEB-BASED CURRICULUM IN PEDIATRIC RADIOLOGY Janet R. Reid, MD,FRCPC, Pediatric Radiology, Cleveland Clinic Children’s Hospital, Cleveland, Ohio; Marilyn J. Goske, MD; Mariana Hewson, PhD; Nancy Obuchowski, PhD Purpose: We developed a web-based interactive curriculum for first year residents in pediatric radiology and formal evaluation by the residents provided feedback and validation. Materials and Methods: In a computer laboratory, residents critically evaluated six intranet-based modules for educational value and content including quality of pre- and posttest questions, interactive graphics, and illustrations. From an Excel database group mean test scores were compared to assess resident’s mastery of each topic using the two-tailed sign rank test. Subjective comments were recorded. Results: Nineteen residents completed six modules. Four completed 4 or fewer. There were 10 pre- and posttest questions for each module. The mean change in test scores was 1.3 to 2.6 (p<.001). Greater than 85 % of residents stated the curriculum increased their knowledge and web-based learning was preferable to a standard textbook. Educational content was rated as valuable. Specific comments for improvement will be discussed.

Conclusion: Residents preferred this web-based curriculum over standard methods and strongly endorsed it as a learning tool. Resident feedback altered the design but not the content of the modules. This format is consistent with the ‘‘life long learning’’ recommended by the ABR.This presentation was supported by an SPR Grant. (This presentation was supported in part by a Seed Grant from the Research and Education Foundation of the Society for Pediatric Radiology.)

86 PINHOLE IMAGING OF 131I-METAIODOBENZYLGUANIDINE (MIBG) IN A HIGH-RISK NEUROBLASTOMA MURINE MODEL Roberto Accorsi, Ph.D., Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA; Michael J. Morowitz, M.D.; Martin Charron, M.D.; John M. Maris, M.D. Purpose: To evaluate primary tumor growth and metastatic dissemination in a murine model of high-risk neuroblastoma using 131 I-MIBG scintigraphy. Methods: Neuroblastoma xenografts were created by inoculation of human neuroblastoma cell suspensions into the subcutaneous flanks of athymic nude mice. After measured tumor volumes exceeded 200 mm3, each mouse received an intraperitoneal injection of 18 lCi/g 131I-MIBG. Pinhole scintigraphy was then performed under anesthesia to evaluate each mouse for biodistribution of MIBG and to attempt to visualize the flank tumors. Each mouse was imaged for 10 minutes on a gamma camera equipped with a 3-mm pinhole (magnification 3.75) on one head and a HEGP collimator on the other (at contact). Results: Images demonstrated absorption of radiolabeled MIBG and visualization of flank tumors. Analysis of the images allowed for quantification of relative MIBG uptake in different organs as well as the tumor and for determination of linear and area measurements of the tumors. Conclusion: High-energy pinhole imaging effectively demonstrates uptake of radiolabeled MIBG by human neuroblastoma tumors in a murine laboratory model. This technique allows for in-vivo assessment of the tumor burden. In the future, we plan to use the method to evaluate metastatic spread and therapeutic efficacy in xenograft and orthotopic models.

87 RENAL CELL CARCINOMA FOLLOWING ADVANCED STAGE NEUROBLASTOMA IN EARLY CHILDHOOD: A CASE SERIES AND REVIEW OF THE LITERATURE Sandra L. Wootton-Gorges, M.D., Department of Radiology, University of California, Davis, Medical Center and U.C. Davis Children’s Hospital, Sacramento, CA; Julie M. Fleitz, MD; Lorrie F. Odom, MD; Josephine Wyatt-Ashmead, MD; Daniel C. West, MD; Kenneth W. Martin, MD; et al Renal cell carcinoma (RCC) is rare in children, comprising 1-3 % of primary pediatric renal tumors. We report four patients treated for advanced stage neuroblastoma (NB) who developed RCC later in life, and review the literature. Two of our patients had extra-abdominal primary NB, a finding not previously reported. Reviewing all cases, 11/16 had high stage NB (>= III) at diagnosis. RCC developed an average of 14.7 y after diagnosis of NB (range 2.4–34 y). Bilateral RCC was seen in 5/16. Development of RCC could not be related to prior radiation therapy or chemotherapy. Histology included clear cell, oncocytic and anaplastic varieties.

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88 IMAGING CHARACTERISTICS OF HEMOPHAGOCYTIC LYMPHOHISTIOCYTOSIS Nancy E. Fitzgerald, M.D., E. B. Singleton Diagnostic Imaging, Texas Children’s Hospital, Houston, Texas; Kenneth L. McClain, MD,PhD Purpose: To describe radiographic findings in the chest, abdomen and central nervous system in hemophagocytic lymphohistiocytosis (HLH), a type 2 histiocytosis. Materials and methods: Retrospective review of the 18 cases of HLH identified at Texas Children’s Hospital between April 1992 and September 2001. Results: Patient ages ranged from 5 days to 16.5 years, with mean age at diagnosis of 3.9 years. CNS symptoms preceded other systemic symptoms in three cases. Six patients required bone marrow transplant. Eight of the 18 patients (44 %), including one postbone marrow transplant, died of multiple organ failure.Common chest findings included progressive alveolar-interstitial opacities with pleural effusions. Abdominal ultrasound and CT studies were remarkable for hepatosplenomegaly, increased echogenicity of the porta hepatis, gallbladder wall thickening, renal enlargement and ascites. The most common brain imaging finding was periventricular leukoencephalopathy, with progressive enlargement of ventricles and extra-axial fluid spaces. In one uncommon presentation, parenchymal and extra-axial hemorrhage initially suspected due to nonaccidental trauma was later found related to hemorrhagic venous infarct from transverse sinus thrombosis. Conclusion: While common imaging findings of HLH resemble those of sepsis and coagulopathy, knowledge of this disorder may be helpful in diagnosis and in avoiding unnecessary studies.

89 FDG-PET VERSUS BONE SCINTIGRAPHY IN THE EVALUATION OF LANGERHANS CELL HISTIOCYTOSIS: PRELIMINARY FINDINGS Larry Binkovitz, MD, Children’s Hospital, Columbus, OH; Randal Olshefski, MD; Brent Adler, MD Bone involvement in Langerhans cell histiocytosis, LCH, is common. Both bone scintigraphy and plain films are used to assess for the presence lesions but lack sensitivity for disease presence and specificity for disease activity. FDG-PET is a sensitive technique for identifying bone lesions, especially when histiocytes are present. It may give more specific information regarding lesional response to therapy than bone scintigraphy or radiography and permit more accurate determination of treatment endpoints. We report our early experience with FDG-PET in LCH with comparison to bone scintigraphy and radiography.

Materials and Methods: Over the past year we have treated 25 children (11M, 14F) ranging in age from 11–129 m (X=65 m). Of the 25 patients 16 were for MR, 6 for CT, and 3 for IR. Sixteen patients were treated with 6–12 ounces of oral Mountain Dew (50 mg caffeine per 12 ounces). Nine patients were treated with IV caffeine (10 mg/kg, maximum 100 mg). All children were continuously monitored and symptoms were recorded. In both groups children were sedated with a combination of IV Nembutal, Fentanyl, and/or Versed. Results: Of the 16 children receiving Mountain Dew all consumed between 6 and 12 ounces. Within 20 minutes all children were noted to be improved, with diminished agitation and/or sleep. No child required admission to the hospital or suffered a complication. Of the 9 children receiving IV caffeine, 8 received a total dose of 100 mg while one received 75 mg. Eight of nine had prompt resolution of their symptoms. One child with a metabolic disease did not improve. Again no hospitalization or complication occurred.

91 CONTEMPORARY PRACTICE OF PEDIATRIC HELICAL CT USING WEB-BASED TECHNOLOGY Caroline L. Hollingsworth, MD, Radiology, Duke University Health System, Durham, NC; Donald P. Frush, MD; Mark D. Cross; Javier Lucaya, MD Purpose: Our purpose was to determine pediatric body CT practice, emphasizing parameters affecting radiation dose. Materials and Methods: Information was obtained using a webbased survey sent electronically to the SPR/ESPR membership. Topics include demographics, techniques for oral and IV contrast media, and age-based (0–4, 5–8, 9–12, 13–16, >16 yr) scan parameters (e.g. mA, collimation, pitch). Results: 92 responses. Notable results include: – 25 % use multislice HCT. – 33 % use oral contrast routinely for abdominal trauma.50 % routinely use power injector. – 98 % use low-osmolar IV contrast. – 2 times the use of < 2.0 ml IV contrast for chest vs. abdomen HCT. With respect to radiation exposure: – While ageadjusted scanning doses occur, relatively high mA is often used. For example, only 57 % of chest or abdomen HCT in young children (0–4 yr) and 38 % of abdomen HCT in older children (5–8 yr) are performed using <150 mA. In addition, 13 % of children >4 yr are exposed to =200 mA for routine chest CT. – 65 % use 120 kV. Only 4 % use <120 kV. – Approximately 20 % did not know specific scan parameters. Conclusions: While pediatric radiologists do practice age-adjusted, lower dose HCT, variable scanning techniques are utilized, imparting high radiation exposure. Information about current pediatric body HCT practice can serve as a foundation for future recommendations for pediatric HCT.

90 TREATMENT OF PARADOXICAL HYPERACTIVITY WITH ORAL AND INTRAVENOUS CAFFEINE: A PILOT STUDY

92 OVEREXPOSURE OF CHILDREN WITH COMPUTED RADIOGRAPHY

Robin D. Kaye, M.D., The Children’s Hospital of Philadelphia, Philadelphia, PA; Joan T. Rubin, B.A.; Victor Villemange, MD; Marybeth Bartko, R.N.; Richard B. Towbin, MD

Steven Don, MD, Mallinckrodt Institute of Radiology, St. Louis Children’s Hospital, St. Louis, Missouri; John J. Chaney, RT(R); Glenn Fletcher, PhD; Charles F. Hildebolt, DDS, PhD; Tawana M. Hughes

Purpose: Paradoxical hyperactivity (PH) is a troublesome complication resulting from sedation. PH is the most common side effect of sedation occurring in as many as 6 % of children. Children become inconsolable and highly agitated making their on-going care and discharge challenging. We have begun treating children with oral and intravenous caffeine in an attempt to resolve their symptoms.

Purpose: To determine if children are overexposed during computed-radiography (CR) examinations. Methods: The accuracy of the exposure index [EI, a measure of incident x-ray energy on a CR plate] was tested with a hand phantom. EIs were recorded for randomly-selected exposures of the chest,

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abdomen, skull, cervical spine, and appendicular skeleton and compared with the optimum EI, which is 2000 ± 300 (0.5 to 2 mR). Results: There was no discrepancy between the EI calculated for the hand phantom and the experimentally measured exposure. EIs were recorded for 522 examinations. Of these, 277 (53 %) were within the optimum range, 22 (4 %) were underexposed, and 224 (43 %) were overexposed. The examinations that had mean EIs within the optimum range were for the abdomen (mean EI ¼ 2032), cervical spine (1936), chest (2125), pelvis (2184), and skull (2204). Appendicularskeletal examinations with EIs above the optimum range were for the ankle (2360), elbow (2714), forearm (2671), foot (2609), hand (2732), knee (2544), and tibia/fibula (2463). Although appendicular examinations may involve two exposures per plate, this did not affect the EIs. Conclusion: There is a tendency to overexpose children with CR, especially for appendicular imaging. With CR plates (unlike film), overexposure results in acceptable images. The inclination to err with overexposure rather than underexposure may account for the results of this study.

and exposures at three mAs settings were performed using CR and DR systems. Alternating CR and DR images at equivalent kV/mAs were obtained on children who were to have two chest films within 24 hours after IRB approval and parental consent. Three blinded pediatric radiologists rated the conspicuity of the support equipment, bones, and overall image quality for each pair using side by side monitors and questionnaires. Results: For the phantom study, 35 of 36 DR images were rated equivalent or superior to CR, where CR dose was greater than or equal to DR (p<0.001). Eight patients of our planned 56 have been enrolled; thus far, DR quality was rated equivalent or superior in 58 % (p=0.291). Conclusions: From the phantom study, DR image quality is at least equivalent to CR (even at lower mAs setting). The patient trial is ongoing. DR imaging is a promising new technology that provides near instantaneous imaging and has potential for decreasing radiation dose.

95 PEDIATRIC BODY CT: HAS RECENT PUBLICITY AFFECTED TECHNIQUES CONTRIBUTING TO RADIATION DOSE?* 93 DOSE COMPARISON: DIRECT RADIOGRAPHY VS. COMPUTED RADIOGRAPHY VS. 400-SPEED FILM SYSTEM John D. Strain, MD, Children’s Hospital, Denver, CO; Ephraim J. Imperial, RT; David S. Herron, MS; Deborah Nedeau, RT

Ana Quinones, MD, Radiology, Duke University Health System, Durham, NC; Donald P. Frush, MD; Lane F. Donnelly, MD; Caroline L. Hollingsworth, MD; Matthew A. Ziegler

Purpose: Interest in radiation exposure has increased following the articles of February, 2001 that defined an increased cancer risk to a pediatric population from medical imaging. The purpose of this article is to compare the radiation dose required for direct radiography, computed radiography and a 400 speed screen system. Materials and Methods: Radiation exposure for KUB and AP shoulder obtained using direct radiography (Swissray ddR MultiSystem), computed radiography (Agfa ADC Compact and ADC Solo) and a 400 speed screen system (Film Dupont Ultravision Rapid, Screen Curix Ultra UVG) were compared. Techniques were recorded for infant, toddler, child, young adult and adult. DR images were phototimed. CR technique was recorded when the exposure level recommended by the manufacturer was achieved (2.1–2.3). Images were viewed on PACS workstation (GE Pathspeed) and image quality was subjectively assessed. Results: Subjective image quality for DR and CR were similar. The exposure levels for DR and screen system were comparable. Dose for CR was twice that for the screen system in all age patients. Conclusion: The radiation dose for CT is similar to that of a 400 speed screen system. The radiation dose for CR is twice that of a conventional 400 speed screen system. Even greater dose is needed for young adults and adult patients.

Purpose: Based on a previous study, our purpose was to determine the impact of current dose reduction literature on pediatric helical CT technique. Materials and Methods: Using identical methodology (AJR 2001; 18:73–79), and a new 3 month period, outside pediatric body (chest, abdomen) CT examinations for radiologic consultation at two institutions were reviewed. Data included tube current (mA), kilovoltage, collimation, and pitch. Children were again grouped by age (yr): < 5 (n=9); 5–8 (n=8); 9–12 (n=8); 12–16 (n=17). CT parameters were compared between the new and prior surveys to evaluate for application of dose reduction techniques. Results: 42 children (22M, 20F) (mean age ¼ 9.6 yr) had a total of 65 examinations (chest=15; abdomen=50). No CT parameters affecting radiation were greater in the more recent survey. Current CT techniques include: 5 % decrease in mean mA (208 vs 198) with a 15 % decrease in mean chest mA (181 vs 213); lower mA (mean 23) for chest vs abdomen CT (previously chest 7 mA higher); and age based slice thicknesses (3–10 mm based on age; previously no difference between 5–16 yr). Conclusion: While this suggests that several parameters are being adjusted for children, many examinations are still performed using parameters which exceed guidelines. A second survey (through 3–01–02) is underway to assess for further improvements potentially due to recent SPR (ALARA) and RSNA forums.

94 PORTABLE COMPUTED RADIOGRAPHY VERSUS DIGITAL RADIOGRAPHY IN THE ICU: WHO WINS ON QUALITY AND DECREASING RADIATION DOSE?

96 RECENT SHARP INCREASE IN PEDIATRIC BODY CT UTILIZATION IN A LARGE URBAN TEACHING HOSPITAL – IS THERE A REASON FOR CONCERN?*

Sunny Chung, MD, Cleveland Clinic Foundation, Cleveland, OH; Marilyn Goske, MD; Robert Cecil, PhD; William Davros, PhD; Janet Reid, MD; Stuart Morrison, MD; et al

Tara M. Lawrimore, MD, Radiology, Masschusetts General Hospital, Boston, Massachusetts; Sjirk J. Westra, MD; Hamid Salamipour, MD; Mark E. Mullins, MD; Diego Jaramillo, MD; Scott G. Gazelle, MD PhD

Purpose: A recently developed digital radiographic detector system (DR) provides a near instantaneous image at bedside. Our purpose is to compare image quality of a prototype portable DR system with computed radiography (CR) in a pediatric intensive care unit (PICU) and image quality and radiation dose in a phantom study. Materials and Methods: DR equipment was retrofitted onto a portable unit. Support equipment was incorporated into phantoms,

Purpose: We analyzed pediatric CT utilization at our large urban teaching hospital, as a first step for cost-effectiveness analyses. Materials and Methods: We queried our database for annual pediatric imaging utilization and pediatric CT utilization, subdivided according to area (head, neck, chest, abdomen and extremity). These data were divided by total imaging studies and total CT studies.

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Results: Between 1988 and 2001, total CTs increased from 17,000 to 71,000, and pediatric CTs from 1,200 to 2,900, whereas all imaging studies increased from 244,000 to 448,000 and all pediatric studies from 22,000 to 31,000. While the proportion of pediatric studies decreased from 7.1 to 6.9 % from 1995 to 2001, the proportion of pediatric CTs increased from 6.0 to 9.4 % (P<0.001). The sharpest increase in pediatric CTs has been in studies of abdomen, pelvis and chest, whereas the proportion of head and neck studies has decreased, and extremity CT utilization has remained relatively stable. Conclusion: Pediatric CT utilization has increased substantially during the past decade, both in absolute and relative terms, particularly in the chest and abdomen. These data, in combination with published age and gender-specific risk estimates and our ongoing institutional radiation dose survey, as modulated by the use of pediatric dose reduction protocols since 1999, will allow populationbased cost-effectiveness estimates for CT.

Results: While W/Wn was 1.53 ± 0.27 in females, and 1.49 ± 0.20 in males, BMCt/BMCtn, L/Ln and F/Fn were 1.12 ± 0.11, 1.25 ± 0.20, and 2.12 ±0.52 in females, 1.07 ± 0.10, 1.14 ± 0.12, and 2.34 ± 0.51 in males. F/Fn and L/Ln were moderately correlated with W/Wn (r2 ¼ 0.65–0.47, and 0.41–0.28, respectively, in females and males), BMCt/BMCtn was poorly correlated with this parameter (r2 ¼ 0.39 in females, and 0.13 in males). Conclusion: The alterations in L and F differed in males and females. Moreover, the increase of BMCt is rapidly limited to approximately 10 % in both sexes.Clinical images to be shown : DXA scans and results. Normal value curves.

SCIENTIFIC EXHIBITS NEUROIMAGING

97 BONE MINERAL DENSITY (BMD) IN SURVIVORS OF CHILDHOOD BRAIN TUMORS Sue C. Kaste, DO, St. Jude Children’s Research Hospital, Memphis, TN; Mark V. Sapp, MD; Tami J. Shidler, RN; Lisa Dillard; Xiaoping Xiong, PhD; Junhong Zhu, MS; et al Purpose: Cancer treatment, inadequate nutrition, sedentary lifestyle, secondary neuroendocrine and neurologic sequelae predispose pediatric brain tumor survivors to bone mineral deficits. Methods and Materials: After IRB approval, we retrospectively reviewed medical records of 72 patients treated and followed at our institution. We correlated lumbar spine QCT BMD results with clinical parameters including age at diagnosis, gender, race, cancer treatment, endocrinopathy and neurologic deficits. Results: Forty-four (55 %) were female; median age at diagnosis 6.48y (range 0.49–19.84y); 29 were treated for medulloblastoma (36.25 %). Mean age at time of study 14.17 y (range, 4.3–25.98y). Median time from diagnosis was 6.31y (range, 0.02–17.39 y). Mean BMD z-score was )1.389 (SD=1.579; SE=0.186), significantly decreased compared with normal values (P<0.00001). Fifty-one (64.56 %) had endocrinopathies. Normal ambulatory function was present in 58 (72.5 %); 10 (12.5 %) had ataxic gait; nine (11.25 %) ambulated with assistance; one used wheelchair or crutches and one used a leg brace. Conclusions: Children and adolescents who have survived treatment for childhood brain tumors have significantly decreased BMD placing them at significant risk for fracture, particularly when associated with falling resulting from of gait instability and seizures.

98 BONE MINERAL CONTENT AND BODY COMPOSITION IN OVERWEIGHT HEALTHY ADOLESCENTS Pierre M. Braillon, PhD, MD, Pediatric Imaging, Hospital Debrousse, Lyon, France; Adrian Serban, MD Purpose: To assess the bone mineral content and body composition in lean and fat masses in overweight youths, and to compare the measured values with normal data. Materials and methods: We studied 227 patients (139 females, 88 males) aged 4.4–18.0 years. The actual weights (W) ranged from 28.1 kg to 115.3 kg in the females (BMI: 27.9 ± 5.7), and from 29.0 kg to 134.5 kg in the males (BMI: 27.1 ± 3.7). A total body scan was obtained on a XR-36Ò DXA system (Norland Medical Systems, Fort Atkinson, Wi). The measured values of the total bone mineral content (BMCt), lean mass (L), and fat mass (F) were compared to their corresponding normal values, BMCtn, Ln, and Fn, calculated for the normal weight for the actual height of the patients (Wn).

1 SPATIOTEMPORAL MAPPING OF CEREBRAL MATURATION IN CHILDHOOD USING 2D MAGNETIC RESONANCE SPECTROSCOPIC IMAGING (MRSI) – PRELIMINARY REPORT Patrick Barnes, MD, Radiology, Lucile Packard Children’s Hospital at Stanford, Palo Alto, CA; Jamie Dermon, SMS1; Dan Spielman, Ph.D Purpose: Assess 2D MRSI for spatial and temporal mapping of cerebral maturation in early childhood. Materials and Methods: Eleven children (1 day to 9 years postterm age) with normal neurodevelopment had 2D MRSI at 1.5T. Regions of interest (ROI) for MRSI were selected from T2 images for (1)the basal ganglia and anterior limb of the internal capsule, (2) the thalami and posterior limb of the internal capsule, (3) occipital lobes, and (4)the frontal to parietal white matter using the PRESS method (TR 1500ms, TE 144ms, 10mm slice, 24cm FOV, 16x16 matrix, 2 averages, 2.25cc voxel). Peak areas, ratios, and maps for n-acetyl-aspartate (NAA), choline (Cho), myoInositol (mI), and creatine (Cr) were calculated using GE FuncTool software on a SunSparc workstation. Comparisons were made with conventional MRI and diffusion tensor (DTI). Results: Analysis shows the following trends regarding a spatiotemporal cerebral maturation gradient: increasing NAA/Cho and NAA/Cr, plus decreasing Cho/Cr and mI/Cr with age as well as caudal to cephalad, central to peripheral, and posterior to anterior. Spatial and temporal metabolite variations were similar but not identical to myelination patterns as determined from T2 and DTI. Conclusions: MRSI maturation criteria probably reflect a combination of myelination, neuroaxonal development, and synaptogenesis. Thus, quantitative MRSI may provide new insights into cerebral maturation.

2 STUDY OF WHITE MATTER MATURATION FROM BIRTH THROUGH ADULTHOOD USING HIGH b VALUE DIFFUSION WEIGHTED IMAGING Dafna Ben Bashat, PhD, The Wohl Imstitute for Advanced Imaging, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel; Liat Ben Sira, MD; Moshe Graif, MD; Elka Miller, MD; Talma Hendler, MD, PhD; Yaniv Assaf, PhD; et al White matter (WM) maturation is an important part in brain development and continues from birth through adulthood. High b value diffusion weighted imaging using q-space analysis was shown