Sonography of acute right side colonic diverticulitis

Background: To describe the prevalence and sonographic findings and ultraso und diagnostic accuracy of the right side colonic diverticulitis in patient s having right lower abdominal pain with indeterminate nature. Methods: A total of 934 patients with acute right lower abdominal pain of c linically indeterminate nature were referred for ultrasound examination (US ). US studies were performed with 3.5 to 7.0 (or occasionally 10) MHz trans ducers using graded compression method. Twenty-three patients were finally diagnosed to have an uncomplicated acute diverticulitis of the right colon. The gray-scale sonographic images were reviewed. A retrospective study was undertaken to evaluate diagnostic contribution of US. Results: The prevalence of acute right side colonic diverticulitis was 2.5% in patients with clinically indeterminate acute right lower abdominal pain . Locations of the inflamed diverticula include cecum in 6 patients, proxim al ascending colon in 15 patients, and distal ascending colon in only 2 pat ients. Sonography detected 21 inflammed diverticula with 1 false positive a nd 2 false negative results. The most typical sonographic feature of an inf lamed diverticulum of right side colon was a rounded or oval-shaped hypoech oic or nearly anechoic structure (52%) protruding out from the segmentally thickened colonic wall. Some of them might contain strong echoes representi ng gas or feces (43%). or stone in the lumen (5%). Regional pericolic or pe ridiverticular fat thickening was noted in 57% of patients, and segmental c olon wall thickening in 38%. US examination yielded a sensitivity of 91.3%, a specificity of 99.8%, an overall accuracy of 99.5%, a positive predictiv e value of 95.5%. and a negative predictive value of 99.7%. A positive sono gram made the likelihood of acute right side diverticulitis 456.5 times gre ater compared with the pretest clinical impression. US differentiated acute right side colonic diverticulitis from acute appendicitis with a 100% accu racy. Conclusions: Ultrasound can be extremely useful in diagnosing acute right s ide colonic diverticulitis. Careful ultrasound evaluation of the right colo n and the cecum may facilitate a correct diagnosis and help differentiate f rom acute apprendicitis, and steer the surgeon to a more effective manageme nt. (C) 2001 Excerpta Medica, Inc. All rights reserved.