Sigmoid diverticulitis: diagnostic role of CT--comparison with barium enema studies.

The diagnostic value of computed tomography (CT) and barium enema (BE) studies was evaluated prospectively in hospitalized patients with the presumptive diagnosis of acute sigmoid diverticulitis based on the presence of left-lower-quadrant pain and tenderness, fever, and leukocytosis. Of 56 patients, 11 had sigmoid diverticulitis confirmed at surgery and 16 by clinical response to medical therapy. CT, performed in all diverticulitis patients, had positive results in 93% (25 of 27). These compared favorably with BE study results, of which 80% (20 of 25) were positive. Neither examination had false-positive results. In the 29 patients who did not have diverticulitis, an alternative diagnosis was made by means of CT in 20, but in only three by means of BE studies. Many of the extracolonic abnormalities recognized at CT were clinically unexpected and necessitated emergency surgery. The excellent sensitivity and specificity of CT coupled with its versatility in the detection of extracolonic disease give it an advantage over contrast enema studies for diagnosis of sigmoid diverticulitis. CT should be the initial study in acutely ill patients, especially when the clinical features are atypical for sigmoid diverticulitis.