Eugene Gedgaudas

Evaluation of abdominal fistulas with computed body tomography (CT).

Twenty-nine patients with 32 abdominal fistulas were evaluated by sinograms and CT. Sinograms were superior to CT in displaying the fistulous tract and its communications to specific organ systems. Ct added information affecting treatment plan or surgical approach by defining extent, nature and location of underlying disease, by eliminating overlap opacified fistulas, cavities, bowel loops and surface contaminations and by detecting additional undrained abscesses or recurrent tumor masses. While sinograms remain the initial procedure in the evaluation of abdomina fistulas, CT offers a useful secondary modality in selected instances.

Radiology of the human segmental pancreatic transplant

Twenty-three segmental pancreatic transplants have been performed for treatment of diabetes mellitus between July 1978 and March 1981 at the University of Minnesota. The radiologic evaluation of the transplants included ultrasonography,15Se-methionine isotope scanning, angiography, and CT scanning. Transplants of normal appearance by these studies had normal endocrine function. Pathologic findings are presented and their significance discussed.

Computer tomography, radionuclide imaging and ultrasonography in hepatic mass lesions.

The livers of 86 patients comprising this report were examined by both transmission computerized tomography (CT) and radionuclide scans (LS). Fifty-nine of them were also examined by gray-scale ultrasound (US). In a comparative study, the strengths and weaknesses of each modality were evaluated. CT demonstrated 85%. US 82%, and LS 73% of masses involving the liver. Because of better resolution and sectioning capabilities, together with stop-motion imaging, CT and US detected smaller and deeper mass lesions than did LS. However, LS was more informative in hepatocellular disorders than was US or CT. Our experience indicated that information obtained on the liver and surrounding structures by each imaging modality used here tends to be somewhat unique, and thus these procedures complement one another rather than being competitive.

Image Format and Viewers for Computerized Tomographic Scanners

Little technical information has been made available on CT image format or viewers. For large matrix displays (320 x 320 or 512 x 512), a high quality TV monitor with a bandwidth of 10 MHz or greater is required. If only a single field of a two to one positive interlaced TV monitor is displayed, an 875 line rate TV would be required in order to display the entire matrix. For image recording, a transparency system such as a multi-format unit or a 105 mm roll film camera will generally provide the best results. Finally, in order to improve the final CT image, various picture processing routines may be used. These include pre- and post-reconstruction smoothing, edge enhancement and image subtraction.

Roentgenologic Diagnosis of Congenital Heart Disease in Infants and Children

A radiologic classification is presented to aid in the preliminary separation of congenital cardiac anomalies into physiologic groups. Further analysis of findings in each group can be made to arrive at a specific diagnosis. In most cases a firm clinical diagnosis can be made from fluoroscopic and radiographic findings plus the other clinical data. In difficult or complicated cases or when surgical correction is contemplated, more specialized technics such as angiocardiography and retrograde aortography may be valuable. Some indications for the special technics are listed.

Acceptance Testing of a Computerized Tomographic Scanner

Computerized tomographic scanners have gained quick and widespread acceptance in diagnostic radiological practice. The cost of such units is currently about a half million dollars. Technologically, they are one of the most complicated pieces of equipment to be found in a radiology department. Because of the cost and complexity, it seems logical to set up performance specifications, acceptance tests, and a quality assurance program for a CT scanner. Pertinent performance specifications are herein described and discussed. In order to assure that the CT unit does meet specifications, appropriate acceptance tests are likewise discussed. Finally, a basic quality assurance program is outlined with an indication of the tests to be performed and their time frequency.