Helical CT signs in the diagnosis of intestinal ischemia in small-bowel obstruction

OBJECTIVE. The purpose of our study was to determine prospectively the valu e of helical CT and of various signs of ischemia in the context of acute bo wel obstruction SUBJECTS AND METHODS. All patients seen over a 3-year period with a CT diag nosis of small-bowel obstruction were included. There were 144 examinations in 142 patients. Images were interpreted prospectively with consensus by a fellow and an experienced gastrointestinal radiologist. Attention was focu sed on the presence of the following signs of strangulation and ischemia: r educed enhancement of the small-bowel wall, mural thickening, mesenteric fl uid, congestion of small mesenteric veins, and ascites. A diagnosis of isch emia was made if enhancement of the bowel wall was reduced or if at least t wo of the other signs were found. Results were correlated with surgical fin dings in 73 cases and clinical follow-up in 71 cases. RESULTS. A diagnosis of ischemia was made at surgery in 24 patients. CT dia gnosis was correct in 23 patients (96% sensitivity). Then were nine false-p ositive diagnoses (93% specificity). The negative predictive value of CT wa s 99%. Reduced enhancement of the bowel wall had a sensitivity of 48% and s pecificity of 100%. mural thickening had a sensitivity of 38% and specifici ty of 78%, mesenteric fluid had a sensitivity of 88% and specificity of 90% , congestion of mesenteric veins had a sensitivity of 58% and specificity o f 79%, and ascites had a sensitivity of 75% and specificity of 76%. CONCLUSION. Helical CT is a highly sensitive method to diagnose or rule out intestinal ischemia in the context of acute small-bowel obstruction.