Biomedical subjects
Publications and source records attributed to E K Fishman.
High resolution CT of a fixed-inflated air-dried lung was obtained from a patient with rounded atelectasis. The dense periphery of the mass was shown to correspond to an invagination of the pleura, and the central lucency to slightly aerated atelectatic lung parenchyma.
Although urticaria and facial and peripheral edema are well recognized idiosyncratic reactions to ionic contrast medium, to our knowledge, isolated angioedema of the small bowel has not been reported previously. We present a case of acute onset of small bowel edema and ascites during the infusion of iodiated contrast medium.
A retrospective review of 275 consecutive patients with symptomatic Crohn disease to determine the frequency and type of bladder involvement yielded 14 cases. All 14 patients had a long standing history of Crohn disease with other positive radiologic features at the time of detection of bladder involvement. Patients were categorized into two groups based on the CT findings: Group I (n = 4) had focal bladder wall thickening adjacent to an extravesical soft tissue mass and/or focal bowel wall thickening; Group II (n = 10) had fistula formation with intravesical air with associated focal bowel wall thickening and/or extravesical soft tissue mass. Bladder involvement in Crohn disease is a progressive pathological process that can result in formation of an enterovesical fistula. The patient may come to radiologic attention at any stage in the course of the disease. Computed tomography is a sensitive and noninvasive method of evaluating the bladder and can be used to identify patients in the prodromal stage who are at risk of developing enterovesical fistulae. Timely intervention may prevent frank perforation into the lumen of the bladder by an inflammatory mass.
Visualization of portal venous air in adults is usually an ominous sign of impending death. The case reported below demonstrates portal vein gas with a benign course in a patient with a duodenal perforation following endoscopic retrograde cholangiopancreatography.
Computed tomography assessment of 634 surgically proven solitary pulmonary nodules included 12 pulmonary carcinoid tumors. Five were central (involving or directly abutting the bronchial tree), and seven were peripheral (surrounded by parenchyma). Three central and one peripheral lesion had CT numbers indicative of focal calcifications, frequently in the periphery of the nodule. Nodule size ranged from 1.2 to 3 cm. Nine nodules were smooth and round, two were irregular and lobulated, and in one the entire peripheral contour was difficult to assess because of postobstructive atelectasis secondary to tumor occlusion of the bronchus. The calculated average CT number ranged from 80.5 to 179 HU.
Radiographic identification of pulmonary metastases has proved to be a challenging problem. We applied high resolution CT (HRCT) to 180 post-mortem lung specimens prepared by a method that allows for direct one-to-one pathologic-radiologic correlation. Of the 180 lungs, 32 had pulmonary metastases. The location, number, size, and interstitial changes were evaluated in 32 cases with pulmonary metastases. The pulmonary metastases were peripheral lesions in 94% of these 32 patients, and multiple tumors were found in 91% of these cases. The metastases were less than 1 cm in diameter in 78%. Twenty-two of the 32 cases (69%) had obvious interstitial changes. In 19 of these 22 cases the interstitial change was characterized by the appearance of a "beaded septum" on HRCT. This beaded septal change corresponded directly to tumor growth in pulmonary capillaries and lymphatics and the septal interstitium. This sign was not noted in any of the specimens with pulmonary edema or fibrosis or in normal lungs. We believe that detection of the beaded septum sign on HRCT is highly suggestive of pulmonary metastases.
Simulated femoral neck fractures with varying amounts of distraction were studied using four modifications in a volumetric, three-dimensional CT reconstruction program to allow an objective comparison of volumetric versus surface (thresholded) rendering. Binary classification caused spurious fusion of gaps less than 2.0 mm or, at settings preserving these gaps, produced false holes in adjacent bone. Fracture gaps were visible to 0.0 mm using volumetric CT image rendering technique.
Patients with acquired immunodeficiency syndrome (AIDS) are subject to a variety of infections, including Mycobacteria avium intracellulare, cytomegalovirus, Cryptosporidium, and Pneumocystis carinii. Pneumocystis is most commonly associated with a potentially fatal pneumonia in AIDS patients. Other organ involvement by Pneumocystis is rare. We present a patient with hepatic and presumed splenic infiltration by Pneumocystis.
A case is presented of painful lytic bone lesions of the spine and pelvis as a manifestation of acquired immune deficiency syndrome (AIDS)-related Kaposi sarcoma (KS). Though KS is the most common AIDS-related neoplasm and may involve many organs, radiographic demonstration of bone involvement has not been previously reported. The value of CT in detecting these lesions, which were not evident on bone scan or plain films, is demonstrated.
Computed tomography of 25 cases of enterovaginal (19 cases) or vesicovaginal fistula (6 cases) were reviewed. Underlying causes of fistulization included gynecological malignancy and radiation therapy (14 of 25), inflammatory diseases of bowel (8 of 25), and miscellaneous conditions (3 of 25). A CT finding of contrast within the vagina provided definitive confirmation of the suspected diagnosis of vaginal fistula in 60% of patients (15 of 25), a detection rate superior to conventional examinations in our series. Other CT findings suggestive of vaginal fistulas included detection of air (20 of 25) and/or fluid (5 of 25) within the vagina. Computed tomographic findings associated with vaginal fistulas such as radiation changes, contiguous pelvic mass, or adherent thickened bowel gave clues to the underlying etiology of the fistula and provided important information regarding the extent of disease prior to attempted surgical repair.
Eleven isolated lungs from patients who had received amiodarone therapy and 22 other lungs from age-race-sex-matched controls autopsied at The Johns Hopkins Hospital were inflation fixed, air dried, and examined by high resolution CT (HRCT). The HRCT findings were directly correlated with gross and histologic changes in these lungs. Intralobular septal thickening and visceral pleural thickening on postmortem HRCT were significantly more severe in the lungs from patients who had received amiodarone than in the controls (p less than 0.05). These HRCT findings were directly associated with the presence of mural foam cells and intraalveolar foam cells. These results suggest that amiodarone therapy may lead to the accumulation of mural and intraalveolar foam cells, and the accumulation of these foam cells may account for the changes seen on HRCT.
Three-dimensional volumetric rendering of CT data has proven to be valuable in the evaluation of the hip. Although video loop animation allows review of the anatomy from all perspectives, it does not show the functional range of motion of the femur in the acetabulum. We have developed a technique termed simulated dynamic CT that gives dynamic animated three-dimensional viewing capabilities. This technique incorporates static CT data with gait and movement data to produce a sequence of dynamic images simulating range of motion. Additionally, this technique allows simulation of surgical techniques to visually anticipate the results of reduction and traction and potential limitations in subsequent hip movement. To assess the potential of this technique, two dysplastic hip patients were studied prior to reconstruction. In each case the perspective thus gained led to altered surgical management.
A retrospective review of CT scans on patients referred with either a definitive or a tentative diagnosis of achalasia was undertaken. Twelve patients were identified, of whom nine had proven achalasia. The remaining three patients were later definitively diagnosed with pseudoachalasia, benign stricture, and leiomyomatosis, respectively. Findings in all nine achalasia patients were similar: moderate to marked esophageal dilatation (mean diameter 4.35 cm at carinal level) with normal wall thickness. Findings are in distinct contrast to the three patients with other diseases, in which the degree of esophageal dilatation and/or wall thickness was atypical. Complications in the patients with proven achalasia included secondary carcinoma (one), iatrogenic esophageal perforation (one), and pulmonary aspiration (three). Computed tomography may not be indicated as a routine study, but in complicated cases CT may be invaluable in confirming the diagnosis or in detecting atypical features that may indicate the presence of other diseases or superimposed benign or malignant processes.
Abdominal CT of 230 patients (310 CT examinations) with a diagnosis of malignant melanoma was retrospectively reviewed for the evaluation of small bowel and mesenteric involvement. Seventeen (7.4%) patients had evidence of small bowel and mesenteric involvement on CT. There were four distinct patterns of disease: (a) intraluminal masses in 3 patients; (b) ulcerating lesions in 2; (c) diffuse infiltration in 6; (d) implants in 10. Four patients had more than two patterns of involvement. Of the 10 patients with tumor implants, carcinomatosis was noted in 2. Two patients had intussusception and 4 had extensive mesenteric nodal involvement. Of the 17 patients, 12 (71%) had at least one symptom referable to the gastrointestinal tract, while 5 (29%) were clinically asymptomatic. Fourteen of the 17 patients (82%) had additional intraabdominal metastases to sites other than small bowel and mesentery.
Standard axial CT supplemented by two-dimensional reconstruction in coronal, sagittal, and oblique planes was used to evaluate 35 patients with a history of breast cancer and clinical symptoms suggestive of brachial plexopathy. In five patients, definite tumor recurrence was seen either within the axilla or the neurovascular bundle or near the origin of the brachial plexus at the C5-C7 level. In six patients, there was thickening around the plexus compatible with fibrosis or scarring. In these patients, no mass was seen. In 24 patients, no evidence of abnormality was noted. Reformatted views can supplement transaxial CT and are particularly effective in defining the course of the brachial plexus and detection of tumor recurrence. The oblique views along with orthogonal planes provide optimal visualization of the brachial plexus and are helpful in the detection of tumor involvement.
Of the many steps involved in producing high quality three-dimensional (3D) images of CT data, the data acquisition step is of greatest consequence. The principle of "garbage in, garbage out" applies to 3D imaging--bad scanning technique produces equally bad 3D images. We present a formal study of the effect of two basic scanning parameters, slice thickness and slice spacing, on image quality. Three standard test objects were studied using variable CT scanning parameters. The objects chosen were a bone phantom, a cadaver femur with a simulated 5 mm fracture gap, and a cadaver femur with a simulated 1 mm fracture gap. Each object was scanned at three collimations: 8, 4, and 2 mm. For each collimation, four sets of scans were performed using four slice intervals: 8, 4, 3, and 2 mm. The bone phantom was scanned in two positions: oriented perpendicular to the scanning plane and oriented 45 degrees from the scanning plane. Three-dimensional images of the resulting 48 sets of data were produced using volumetric rendering. Blind review of the resultant 48 data sets was performed by three reviewers rating five factors for each image. The images resulting from scans with thin collimation and small table increments proved to rate the highest in all areas. The data obtained using 2 mm slice intervals proved to rate the highest in perceived image quality. Three millimeter slice spacing with 4 mm collimation, which clinically provides a good compromise between image quality and acquisition time and dose, also produced good perceived image quality. The studies with 8 mm slice intervals provided the least detail and introduced the worst inaccuracies and artifacts and were not suitable for clinical use. Statistical analysis demonstrated that slice interval (i.e., table incrementation) was of primary importance and slice collimation was of secondary, although significant, importance in determining perceived 3D image quality.
We report a case of a 35-year-old woman with a mucinous biliary cystadenoma of the liver. The patient presented with the acute onset of upper abdominal pain and jaundice, symptoms caused by bleeding into the cystadenoma. Findings of a variety of imaging modalities including ultrasound, CT angiography, MR imaging, and endoscopic retrograde cholangiopancreatography are correlated and verified by pathological studies performed on the material obtained surgically.
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