Complications of acute diverticulitis of the colon: improved early diagnosis with computerized tomography.

We have evaluated the diagnostic role of computerized tomography in 42 patients suspected clinically of having a complication of acute diverticulitis (abscess, colovesical fistula, or both). Diverticular abscesses were confirmed at operation in 10 patients. All 10 patients were diagnosed preoperatively on computerized tomography by the triad of diverticula, a segmentally thickened colon, and extravisceral fluid collection with (6 patients) or without (4 patients) associated gas. Contrast enema study suggested the presence of a diverticular abscess in only two of eight patients studied. Colovesical fistulas were confirmed in 12 patients. Eleven of 12 were diagnosed preoperatively on computerized tomography by the triad of air in the bladder, thickened colon adjacent to an area of thickened bladder, and the presence of colonic diverticula. Contrast enema examinations demonstrated the fistula in only three of eight patients studied. The remaining 20 patients proved to have uncomplicated acute diverticulitis. Findings on computerized tomography included the presence of a segmentally thickened colon with diverticula but without the findings of an abscess or a colovesical fistula. Computerized tomography correctly visualized acute diverticular complications in 21 of 22 patients and it excluded an abscess or fistula in all 20 patients with uncomplicated acute diverticulitis who were suspected of having a diverticular complication. Computerized tomography is the most sensitive and specific test for diagnosing complications of acute diverticulitis. It should be an early consideration in patients with suspected diverticular abscesses or fistulas so that appropriate therapy is not delayed.