Biomedical subjects
Publications and source records attributed to E M Bellon.
The authors, in a careful prospective study, report the accuracy of MRI to be comparable to that of pneumoarthrography and arthroscopy in the diagnosis of internal derangements of the knee.
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Cosmetics can produce severe distortion of the orbital contents in MR imaging. This distortion, typical of compounds that exhibit a permanent magnetic moment, results from iron oxide in the pigments used to produce dark shades of makeup. In general, the artifact created by cosmetics does not interfere with interpreting routine head scans. However, if the orbital contents are the subject of clinical concern, the images may then be rendered nondiagnostic. The artifact created by the makeup is propagated along the frequency-encoding axis of the images.
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The process of creating MR images frequently gives rise to artifacts in the final display. Many artifacts may be corrected or ameliorated through an understanding of their cause. This requires familiarity with scanner design; theory of operation; and image acquisition, generation, and display. Some artifacts are obvious, totally degrading the image; others are regional, leaving much of the scan undisturbed. In some cases, the degradation is permanent; in others, the data can be reprocessed or manipulated to yield artifact-free images. Some artifacts are overt and easily identified. Others, such as those caused by phase-shift or gradient-strength effects, are subtle and require careful observation for detection.
In order to attempt to characterize atheromatous plaque dynamics, and to develop standardized techniques of observation of this behavior, 91 arteriographies were performed on 47 subhuman primates (40 Rhesus and 7 Fascicularis) over a 10-year experimental project. Histopathologic examination was performed at biopsy on the majority of animals and at autopsy on all animals. Selected representative arteriograms and histopathologic cross-sections are presented as well as detailed analyses of the various animals' response to atherogenic regimen. Arteriographic stenosis was site specific for 4 sites virtually exclusively: right internal carotid, inferior mesenteric, lumbar, and presacral arteries. There was no distinction within each grade of stenosis (on a 1-4 grade scale) for all arteriograms, and precision reproducibility of arteriographic technique was achieved without regard to age, size, weight, or type of animal. The consistency and exclusivity of arteriographic 4-site pattern of stenosis, together with non-correlation between it and the histopathologic or surgical observations, suggests that the stenosis observed by all of these methods may be partially or completely a function of artefact attributable to technique. At the very minimum, arteriographic and histopathologic methods are demonstrably dissociative and, therefore, the findings of these 2 cannot be compared in grading atherosclerotic plaque advancement or regression.
A case of osteogenic sarcoma of the mandible is presented. The most striking radiologic finding in this case was irregular widening of the mandibular canal, with areas of narrowing and loss of fine parallel cortical margins of the walls of the canal. These changes were accompanied by widening of the periodontal membrane of the adjoining teeth, an early sign of osteogenic sarcoma described by Garrington and colleagues, and loss of lamina dura of the same teeth and one additional adjacent tooth.
We report a case of multiple diverticula of the ureter. The clinical and radiological findings of the previously reported 41 cases, including our own, are analyzed, and the microscopic findings of the condition are reviewed. Multiple diverticula of the ureter or ureteral diverticulosis is most likely an acquired condition with a distinct radiological appearance.
A new xeromammographic needle localization technique for occult breast lesions seen on only one view is described, which permitted successful localization of an occult lesion visible only on mediolateral projection. To test its accuracy, the method was also applied to 15 other cases (16 lesions) where the lesion was seen in two views, but localization was performed as if it were seen in one view only. The technique takes advantage of the geometry of x-ray beam angulation and triangulation.
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On computed tomographic (CT) scans of the abdomen in patients with ascites, there is one consistently recognizable area of the spleen that is not surrounded by fluid. This area, designated the bare area of the spleen, is related anatomically to the upper anterior part of the left kidney, specifically the Gerota fascia. Awareness of this relation enables differentiation of intraperitoneal fluid from pleural fluid on cross-sectional CT images.
Discrepant enhancement of an internal jugular vein on computed tomography during intravenous infusion of contrast material via an upper extremity vein constitutes an abnormal finding. We demonstrate that the greater degree of opacification of the internal jugular vein on the affected side is due to reversal of flow on that side and is indicative of occlusion of a major venous pathway proximally.
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We describe a manually operated system, simple to assemble, that will enable xenon-133 lung ventilation studies to be performed on ventilator-assisted patients. It can be constructed from items readily available. Radiation exposure levels to the operator were measured and are reported.
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To evaluate clinical usefulness of quantitative sacroiliac scintigraphy (QSS) in detecting sacroiliitis, we used a modified, pixel by pixel technique for calculating sacroiliac joint/sacrum uptake ratios (sacroiliac joint index - SII). We studied 90 controls, 18 selected patients with active sacroiliitis, 2 ankylosing spondylitis patients with completely ankylosed sacroiliac joints, 14 patients with nonspecific low back pain and 5 patients with rheumatoid arthritis. In the controls, we found that the SII decreases with increasing age (P less than 0.001) and is higher in males than in females (P less than 0.005). In the patients with active sacroiliitis, 9 out of 14 older than 30 had an abnormal SII; 3 of these patients showed no radiographic or CT abnormalities of the sacroiliac joints. None of the 4 patients with sacroiliitis under 30 years of age had values which fell out of the normal range for their age and sex. Only 1 of the 14 patients with non-inflammatory low back pain had an abnormally high SII. A borderline SII was found in 1 of the 5 patients with rheumatoid arthritis. QSS may be useful in detecting active sacroiliitis, sometimes even before the occurrence of radiologic abnormalities. However, because of its low sensitivity, its clinical usefulness is limited, especially in patients under 30 years of age.