Ultrasound can differentiate complicated and noncomplicated acute colonic diverticulitis: a prospective comparative study with computed tomography

Objective To prospectively assess the diagnostic value of intestinal ultrasound (US) compared to computerized tomography (CT) in differentiating uncomplicated and complicated acute colonic diverticulitis (ACD). Materials and methods During a period of 14 months patients referred to the department of Radiology with clinical suspicion of ACD underwent an US examination. All confirmed US ACD diagnosis were included and subsequently underwent an emergency abdominal CT, used as gold standard. The WSES (World Society for Emergent Surgery) classification of diverticulitis was used. Diverticulitis was prospectively classified as either uncomplicated or complicated. Sensitivity, specificity, positive predictive value, and negative predictive values of US were evaluated. Before CT scan, the radiologist indicated whether they would have required or not a complementary CT scan, based on US findings. Results Of the 240 patients included in our study, 71 (29.6%) were Stage 0, 127 (53%) Stage 1A, and 42 (17.5%) were moderate-severe ACD (stages 1B, 2A, 2B, 3 and 4). The sensitivity of US for diagnosing complicated ACD was 84% and specificity of 95.8%. Most patients (24 of 27) misclassified by US as uncomplicated diverticulitis were classified on CT as stage 1A. From the 148 cases in which the radiologist considered CT unnecessary, only 3 of these revealed signs of complicated ACD on CT; none of them required emergency surgery. Conclusion US is an effective technique to differentiate complicated from uncomplicated ACD. Our results suggest that US, may be a valuable alternative to CT for the initial radiologic evaluation in patients with clinical suspicion of ACD.