Faculty Bibliography

OBJECTIVE: The purpose of our study was to describe the imaging findings and CT characteristics that lead to accurate distinction of large exophytic renal angiomyolipomas from retroperitoneal perirenal liposarcomas, which at times can be confused on imaging studies and even at pathologic examination. MATERIALS AND METHODS: We retrospectively analyzed CT images of 15 large exophytic renal angiomyolipomas and 12 well-differentiated perirenal liposarcomas. Pathologic correlation was available for six of 15 angiomyolipomas and all of the liposarcomas. All examinations were evaluated for lesion size, renal parenchymal defect, enlarged vessels, kidney displacement, lesion encapsulation or margination, associated hemorrhage, and additional angiomyolipomas. The records of patients with tuberous sclerosis or the forme fruste of that condition were excluded from the study. RESULTS: The average size of the angiomyolipomas was 14 x 10 cm. They showed a renal parenchymal defect (n = 15), enlarged vessels (n = 12), renal displacement (n = 14), good margination without a distinct capsule (n = 14), hemorrhage (n = 1), and additional (one or two) angiomyolipomas (n = 4). The average size of the liposarcomas was 18 x 11.6 cm. They showed enlarged vessels (n = 3), renal displacement (n = 11), and encapsulation (n = 4); none showed a renal parenchymal defect, hemorrhage, or associated angiomyolipomas. CONCLUSION: Although large exophytic angiomyolipomas and well-differentiated retroperitoneal liposarcomas may have similar appearances on imaging, careful evaluation for a defect in the renal parenchyma combined with the presence of enlarged vessels in angiomyolipomas should enable accurate differentiation in almost all cases. Achieving an accurate diagnosis can have a significant impact on patient treatment

Although ultrasound (US) is the primary imaging modality of choice in the radiologic evaluation of the female patient with acute pelvic pain, the role of computed tomography (CT) in the evaluation of abdominal and pelvic pain continues to expand. CT may be performed if a gynecologic disorder is not initially suspected, if US findings are equivocal, or if the abnormality extends beyond the field of view achievable with the endovaginal probe and further characterization of pelvic disease is required. Many gynecologic disorders that cause acute pelvic pain (eg, uterine disorders, ovarian disorders, endometriosis, pelvic inflammatory disease, postoperative or postpartum complications) demonstrate characteristic CT findings. Familiarity with these CT appearances is important: It will allow the radiologist to guide appropriate treatment of affected patients and may eliminate the need for further imaging evaluation

OBJECTIVE: The purpose of this study was to determine the CT findings in acute gangrenous cholecystitis. MATERIALS AND METHODS: Four observers retrospectively reviewed CT scans in 75 patients (23 with acute gangrenous cholecystitis, 25 with acute non-gangrenous cholecystitis, and 27 without cholecystitis). The following findings were evaluated: distention, mural thickening, wall enhancement, irregular wall, wall striation, intraluminal membranes, pericholecystic inflammation, gallstones, pericholecystic fluid, enhancement of liver parenchyma, pericholecystic abscess, and gas in the wall or lumen. Sensitivity and specificity of CT for gangrenous cholecystitis and for each finding were calculated. Two reviewers in consensus measured gallbladder dimension and wall thickness. Logistic regression models were used to predict gangrenous versus non-gangrenous cholecystitis. RESULTS: Sensitivity, specificity, and accuracy of CT for acute cholecystitis were 91.7%, 99.1%, and 94.3%, respectively, and for acute gangrenous cholecystitis were 29.3%, 96.0%, and 64.1%, respectively. Findings with the highest specificity for gangrenous cholecystitis were gas in the wall or lumen (100%), intraluminal membranes (99.5%), irregular or absent wall (97.6%), and abscess (96.6%). The difference between the mean gallbladder wall thickness and the short-axis dimension for the two groups with cholecystitis was statistically significant. In three patients with gangrenous cholecystitis, no mural enhancement was seen. Pericholecystic fluid also achieved statistical significance for the diagnosis of gangrene. Multivariate logistic regression analysis showed that the overall accuracy of CT for gangrenous cholecystitis was 86.7%. CONCLUSION: CT findings most specific for acute gangrenous cholecystitis are gas in the wall or lumen, intraluminal membranes, irregular wall, and pericholecystic abscess. Gangrenous cholecystitis is associated with a lack of mural enhancement, pericholecystic fluid, and a greater degree of gallbladder distention and wall thickening

OBJECTIVE: Localized cystic disease of the kidney is a benign nonsurgical condition. Its imaging and clinical features are characterized and differentiated from autosomal dominant polycystic kidney disease, multilocular cystic nephroma, and cystic neoplasm. MATERIALS AND METHODS: Localized cystic disease was diagnosed in 18 patients on the basis of a review of imaging studies, clinical histories, and pathologic proof in four of the 18 patients. Average age at diagnosis was 54 years (age range, 24-83 years). Fifteen of the patients (83%) were men. CT was performed on 18 patients, sonography on nine, excretory urography on six, arteriography on four, and MR imaging on two. RESULTS: Localized cystic disease was unilateral in all patients and characterized by multiple cysts of various sizes separated by normal (or atrophic) renal tissue in a conglomerate mass suggestive of cystic neoplasm. In some patients, involvement of the entire kidney, which was suggestive of unilateral autosomal dominant polycystic kidney disease, was seen. No cysts were seen in the contralateral kidney in 14 patients, and only one or two scattered small cysts were present in four patients. Clinical presentations included hematuria, flank pain, palpable abdominal mass, and localized cystic disease as an incidental finding. None of the patients had a family history of autosomal dominant polycystic kidney disease. Ten patients underwent follow-up (follow-up range, 1-12 years); nine patients underwent imaging follow-up and one patient underwent clinical follow-up, which showed stability of disease. Four patients underwent nephrectomy for suspected renal neoplasm. CONCLUSION: Familiarity with localized cystic disease of the kidney and its imaging findings is important to avoid unnecessary surgery and to differentiate the disease from autosomal dominant polycystic kidney disease

A 64-year-old man presented with recurrence of transitional cell carcinoma attributed to needle tract seeding of tumor 8 months following fine-needle aspiration of a lower pole renal mass

Benign urinary bladder tumors are very rare, leiomyoma being the most common among them. We wish to report a case and discuss the radiological findings with special emphasis on magnetic resonance (MR) imaging

A prospective clinical trial of concomitant interferon-alpha 2b and etoposide was conducted in 24 previously untreated patients with epidemic Kaposi's sarcoma. Eight of 21 evaluable patients (38%) achieved either a complete response (1 patient) or a partial response (7 patients). None of the responders had a prior history of opportunistic infection. Hematologic toxicity was severe, and 8 patients developed an opportunistic infection. The combination of interferon-alpha 2b and etoposide has modest activity, but no additive or synergistic activity was evident in the dose and schedule utilized in this study. The exact role for interferon-alpha in epidemic Kaposi's sarcoma, both as a single agent and in combinations, remains to be determined