Journal of Medical Systems, Vol. 15, No. 2, 1991
MDA-Image: An Environment of Networked Desktop Computers for TeleRadiology/Pathology M a r k E. Moffitt, 1'3 William R. Richli, 1 Cesar H. Carrasco, 1 Sidney Wallace, 1 Stuart O. Z i m m e r m a n , 3 Alberto G. Ayala, 2 Robert S. Benjamin, 4 Shirley Chee, 1'3 Paul W o o d , s Peggy Daniels, 3 Shan-Qun Guo, 1 John Grossman, 1 and Dennis A. Johnston 3
MDA-Image, a project of The University of Texas M. D. Anderson Cancer Center, is an environment of networked desktop computers for teleradiology/pathology. Radiographic film is digitized with a film scanner and histopathologic slides are digitized using a red, green, and blue (RGB) video camera connected to a microscope. Digitized images are stored on a data server connected to the institution's computer communication network (Ethernet) and can be displayed from authorized desktop computers connected to Ethernet. Images are digitized for cases presented at the Bone Tumor Management Conference, a multidisciplinary conference in which treatment options are discussed among clinicians, surgeons, radiologists, pathologists, radiotherapists, and medical oncologists. These radiographic and histologic images are shown on a large screen computer monitor during the conference. They are available for later review for follow-up or representation.
~TRODUCTION The University of Texas M. D. Anderson Cancer Center is one of the world's leading cancer centers devoted to excellence in cancer patient care, research, education, and prevention. The cornerstone of treatment at M. D. Anderson Cancer Center is the multidisciplinary team approach to the total care of the cancer patient. Multidisciplinary conferences are held at M. D. Anderson to discuss treatment options among clinicians, surgeons, radiologists, pathologists, radiotherapists, and medical oncologists. The history of the case, current stage of the disease, and treatment plans are From the Departments of 1Diagnostic Radiology, 2 Pathology, 3 Biomathematics, 4 Medical Oncology, and 5Instructional Development, The University of Texas, M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030. 111 0148-5598/91/0400-0111506.50/0 © 1991 Plenum Publishing Corporation
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discussed. Radiographic and histopathologic images play a crucial role in these discussions. MDA-Image, an environment of networked desktop computers for teleradiology/ pathology, was developed to resolve a pressing need in patient care: better communication of radiographic and pathologic images in multidisciplinary conferences at M. D. Anderson. While radiographic film has always been available for review (via film, although difficult to see in a large conference room), pathologic images have not generally been available.
M A T E R I A L S AND M E T H O D S MDA-Image was developed around the following requirements: 1. Ability to capture and display radiographic and pathologic images from anywhere in the institution. 2. Expandability to all multidisciplinary conferences at M. D. Anderson. 3. Easy operation by beginning computer users. 4. Minimum software development. 5. Low cost.
Radiographic Image Resolution During the development of MDA-Image it soon became apparent it would not be possible to display high-resolution (2k x 2k x 12 bit) radiographic images (i.e., chest radiographs showing metastasis) on low-cost workstations. Also, because file sizes were large, storage, communication, and display of high-resolution radiographic images would not be accomplished within the initial phase (1989-1991) of the MDA-Image project. Currently, medium-resolution radiographs (structures and masses) are digitized at a lk x lk × 8 bit resolution and CT (either bone or soft tissue window), MRI, nuclear medicine, ultrasound, etc., are digitized at a 512 x 512 x 8 bit resolution.
Histopathologic Image Resolution Histopathologic images are digitized at 640 x 480 x 24 bits (8 bits of red, green, and blue (RGB)) resolution. While these images can be dithered to a resolution of 640 × 480 x 8 bits pseudo-color at some loss of image quality, they must be displayed using a 24-bit display card in order to show radiographic and pathologic images simultaneously.
System Configuration The Bone Tumor Management Conference was the first clinical trial of MDA-Image (November 1990). Apple Macintosh Ilci computers connected via AppleTalk over Ethernet were used to capture, store, communicate, and display images between the conference and the departments of radiology and pathology. The Apple Macintosh II computer was selected over IBM PC compatible computers and Unix workstations. The IBM PC does not incorporate a 24-bit image file format as part of the operating system. Consequently, software to display 24-bit images are gen-
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erally proprietary to the hardware display device, expensive, and limited in functionality. Also, display of 24-bit color images requires an additional monitor. The same is true of Unix workstations. In addition, Unix is not an easy operating system to learn for beginning computer users. The Apple Macintosh II incorporates a 24-bit image file format standard within the operating system. This means a wide range of off-the-shelf software for displaying and manipulating 24-bit color images is available. Also, the Apple Macintosh II is simple to connect to a communication network. Lastly, the Apple Macintosh is easy for beginning computer users to learn to operate.
Radiographic Image Capture A Truvel TZ-3X film scanner connected to an Apple Macintosh IIci is used to digitize radiographic film. Select images from a patient's film jacket are marked with a grease pencil by a radiologist and digitized by a scan operator. An image acquisition module supplied by Truvel is used to digitize film from within Adobe PhotoShop. The selected images are then cut, pasted, and sized into separate image files in PhotoShop. These images are stored on the MDA-Image data server.
Histopathologic Image Capture A Sony DXC-750 RGB charge coupled device (CCD) camera and controller mounted on a Nikon microscope is connected to an Apple Macintosh IIci computer by way of a Truevision NuVista 4M video capture card. A video capture program supplied with the NuVista card (Capture) is used to digitize an image once the field of view is selected by the pathologists. These images are stored on the MDA-Image data server. Experiments with RGB frame capture cameras were less than successful. While the image quality from RGB cameras was outstanding, factors such as no live color view of the image before capture, long image-capture times, and the need for a separate blackand-white preview monitor make these cameras cumbersome to operate in this setting.
Image Storage A central image archive was required to store images from different sources for display in the conference. An Apple Macintosh IIci computer with a 170-MB disk drive running AppleShare connected to Ethernet is used for the MDA-Image data server. Image capture and display devices are set up to automatically connect to the MDAImage data server via AppleShare when powered on. The MDA-Image data server acts like just another volume on the desktop. When a patient is registered for the conference, a folder is created from the patient's six-digit hospital number. Patient images are stored in these folders. Image file names identify the type of exam, date of exam, and number of images digitized in the exam. The first two digits identify the type of exam (XR, CT, MR, NM, US, etc.) and the next eight digits identify the date of exam in the form YY/MM/DD. This way exams are grouped by date when listed under MultiFinder. The last digits indicate the number of images digitized for this exam (preceded by a " . " ) . For example, a CT scan dated January 4, 1991,
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in which two images are digitized would be stored in the files CT91/01/04.1 and CT 91/01/04.2. Images are stored in the PICT file format. An average of seven images (radiographic and histopathologic) are digitized per patient. This translates to an average of 3.5 MB of image data per patient. Image Display
An Apple Macintosh IIci with a RasterOps 24-bit display card and a 19-in. Sony monitor is used to display images during the conference. The display resolution is 1024 x 768 x 24 bits (RGB). A 24-bit display card is required to display radiographic grayscale and color pathologic images simultaneously. The RasterOps card incorporates a hardware zoom, which is useful for magnifying regions quickly. Adobe PhotoShop is used to display and manipulate images during the conference. Experiments with RGB projectors were also successful. While the image quality is not quite as good as the 19-in. Sony monitor, these projectors, once permanently installed and calibrated, are ideal for large conference rooms.
RESULTS AND DISCUSSION Although the radiographic images are available during the conference on the Apple Macintosh, film is still used by the radiologist during the conference due in part to the superior radiographic film resolution and in part to the increased number of available images over those chosen for digitization. The availability of pathologic images during the conference has generated the most interest and resulted in greater in-depth discussions on the pathologic findings during case presentations, thus raising the level of understanding of pathology for conference participants (medical staff). MDA-Image has been expanded to include the Soft Tissue Management and Thoracic Sarcoma Conferences. Four additional multidisciplinary conferences are expected to begin using MDA-Image during 1991. To accommodate the expected increase in image storage requirements, a larger image data server is being installed. The server is a Solbourne Series 5 (SUN 4 compatible) running Information Presentation Technology's uShare, which gives a Unix platform AppleShare file server capabilities. Experiments with Network File Services (NFS) for the Macintosh are on-going. The Solbourne data server will initially have 10 GB of magnetic disk storage (approximately 20,000 images). The MDA-Image project has led to other projects utilizing radiographic and histopathologic images on the Macintosh including the production of a CD-ROM of cases from the Bone Tumor Management Conference, image database development, and medical imaging teaching programs. Incorporating these images in treatment records will aid tremendously in verification and interpretation of research data. For example, histopathologic and radiographic images will verify patient eligibility, and follow-up radiographic images will verify determinations of response to therapy. Development of systems to store, communicate, and display medical images has focused on radiographic images during the 1980s. These systems grew out of the development of computer-based digital imaging modatities (CT, MRI, etc.). Conversely, development of systems to store, communicate, and display pathologic images was practi-
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caUy nonexistent during this time. The foremost reason for this was the lack of computerbased imaging systems in the field of pathology to foster the development of telepathology systems. Companies are realizing the field of pathology is as big a market for electronic imaging as the field of radiology. The 1990s should see an explosive growth in the development of telepathology systems, including computer-based microscopes with builtin communication interfaces (Ethemet) and CCD RGB cameras for capturing and communicating pathologic images. The need for radiographic-pathologic correlation (images and reports) should foster the development of picture archiving and communication systems (PACS) connecting radiographic and histopathologic imaging modalities together and the development of extensions to radiology information systems (RIS) for pathologic findings.