The value of initial sonography compared to supplementary CT for diagnosing right-sided colonic diverticulitis

The purpose of the study was to assess the value of initial sonography in the diagnosis of right-sided colonic diverticulitis in comparison with supplementary CT.

A total of 183 consecutive adult patients with right lower quadrant pain (73 diverticulitis, and 110 non-diverticulitis) who underwent both initial sonography and subsequent CT within 24 h were enrolled in this study. Two reviewers retrospectively assessed imaging findings of diverticula, colonic wall thickening, inflammatory pericolic fat, and pericolic abscess for each sonography and CT and then classified each case as non-diverticulitis, simple diverticulitis or complicated diverticulitis. Sonography and CT were independently reviewed at 2-week intervals. The value of initial sonography was assessed through head-to-head comparison with CT results.

Sensitivity, specificity and accuracy for diagnosing diverticulitis were not significantly different between the two modalities (p = 0.366, 0.605 and 0.259, respectively). In addition, the net sensitivity (97.26%) of both sonography and CT was not significantly different from the sensitivity (89.04%) of sonography alone (p = 0.101). Agreement between sonography and CT for the classification of diverticulitis and the four imaging findings was excellent (all κ > 0.8).

Initial sonography can be as effective as CT for the diagnosis of right-sided colonic diverticulitis. Supplementary CT is only needed when sonography is inconclusive.