Acute colonic diverticulitis: prospective comparative evaluation with US and CT.

Abstract

To compare the accuracy of ultrasonographic (US) and computed tomographic (CT) findings for diagnosis of acute colonic diverticulitis. US and CT were prospectively performed in 64 consecutive patients suspected of having acute colonic diverticulitis. Images were interpreted independently in a blinded fashion. Imaging data were compared with the final diagnosis, which was based on initial clinical and follow-up examination results (n = 64) and pathologic (n = 22), endoscopic (n = 21), and contrast enema (n = 15) examination findings. Final diagnosis was acute colonic diverticulitis (n = 33), other acute abdominal condition (n = 24), or unknown (n = 7). Both CT and US findings yielded 84% accuracy. US and CT findings were not statistically significant different in terms of sensitivity (85% and 91%, respectively) and specificity (84% and 77%, respectively). Positive predictive value was 85% for US and 81% for CT; negative predictive value was 84% for US and 88% for CT. When determining alternative diagnoses, US and CT findings yielded sensitivity of 33% and 50%, respectively (difference not statistically significant). CT scans depicted a small pneumoperitoneum overlooked on plain radiographs and US scans. Six pericolic abscesses were depicted with both techniques; three were depicted with CT only. US and CT findings result in similar accuracy for the evaluation of patients suspected of having diverticulitis.