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.