Differentiating neoplastic from nonneoplastic processes in the anterior extradural space.

PURPOSE: To compare neoplastic and nonneoplastic disease in the anterior extradural space (AES) with regard to the contour of the disease and the tethering of the central septum, as seen on axial magnetic resonance (MR) images. MATERIALS AND METHODS: In this institutional review board-approved HIPAA-compliant study, the data of patients who had AES disease determined at MR imaging and underwent diagnostic biopsy were studied. Two blinded observers reviewed the MR images and assigned the patients to one of two groups on the basis of the contour of AES disease: those with a centrally convex disease contour posteriorly and those whose disease contour was tethered in the midline to the posterior aspect of the vertebral body. Biopsy results served as the standard of reference. The two-tailed Fisher exact test, the Breslow-Day test, and κ statistics were used to compare groups. The sensitivity, specificity, and accuracy of the midline tethered contour of AES disease for the detection of neoplasm were calculated. RESULTS: The data of 32 patients (16 men, 16 women; mean age, 68 years) were studied. Seventeen patients had malignant epidural disease. Fifteen patients had nonneoplastic epidural disease: Six patients had hematomas, and nine had abscesses. A greater proportion of AES neoplasms (13 [76%] and 14 [82%] of 17 lesions for observers 1 and 2, respectively) than nonneoplastic AES lesions (four [27%] and three [20%] of 15 lesions for observers 1 and 2, respectively) demonstrated midline tethering of the central septum. For observers 1 and 2, a unilobed or bilobed appearance of AES disease had sensitivities of 76% (13 of 17 lesions) and 82% (14 of 17 lesions), respectively; specificities of 73% (11 of 15 lesions) and 80% (12 of 15 lesions), respectively; and accuracies of 75% (24 of 32 lesions) and 81% (26 of 32 lesions), respectively, for the detection of neoplasm. The mean κ value for interobserver variability was 0.62 (95% confidence interval: 0.35, 0.90). CONCLUSION: AES disease preserving the midline tethering of the central septum is more common with neoplastic disease than with infections or hematomas.

CT features of adnexal involvement in patients with diverticulitis.

OBJECTIVE: The purpose of this study was to evaluate the CT findings in patients with colosalpingeal fistula complicating diverticulitis. MATERIALS AND METHODS: Using a medical records database and radiology information system, we identified the cases of 14 women who underwent colonic resection for diverticulitis and simultaneous salpingo-oophorectomy with or without hysterectomy over a 10-year period. The patients were separated into two groups: group 1 included women with a pathologically proven colosalpingeal fistula, and group 2 included those who had contiguous periadnexal inflammation without a fistula. Preoperative CT scans of these patients were retrospectively evaluated in consensus by two radiologists blinded to the pathologic findings. The presence of adnexal gas and fluid collections was recorded. The findings were compared with those in the operative and pathology reports. RESULTS: Among 14 patients who had sigmoid (n = 13) or cecal (n = 1) diverticulitis, eight patients were in group 1 and six were in group 2. On CT scans, an adnexal collection of gas, either alone or in combination with fluid, was found in seven patients (88%) in group 1 and in no patients in group 2, resulting in 88% sensitivity and 100% specificity in the detection of colosalpingeal fistula. An adnexal collection of fluid alone was found in one patient (13%) in group 1 and one patient (17%) in group 2, resulting in sensitivity and specificity of 13% and 83%. CONCLUSION: In patients with diverticulitis, a collection of gas, either alone or in combination with fluid, within the adnexum is a sensitive and specific predictor of the presence of a fistula between the colon and an adnexum.