Validation by CT of the new ultrasonography classification of acute colonic diverticulitis among Japanese patients

Abstract

Objective: To select patients eligible for outpatient therapy for acute colonic diverticulitis (ACD), we had proposed a new ultrasonography (US)-based classification of ACD. In this study, we validated this US grading system by comparing diagnostic results with those of computed tomography (CT). Methods: We performed a two-part study. In Study 1, we retrospectively analyzed data collected from 116 ACD patients in Japan, who had undergone both US and CT examinations. The severity of inflammation was two grades (I,II) scored as classification of ACD on the basis of US. Study 2: According to US-based classification, we retrospectively evaluated whether 170 patients with grade I were successfully treatable in outpatient hospital setting. Results: 107/107 (100%) US grade I were also CT grade I, and 5/9 (55.6%) US grade II were also CT grade II. The concordance (kappa) value between US and CT grades was 0.698 (SEM = 0.142). Among grade II cases, the findings by US of inflamed diverticulua, pericolitis and abscess > 2 cm in diameter were same as CT. However, CT did not detect an abscess ≤ 2 cm in diameter as detected by US. The retrospective study revealed that 97 (95.1%) of 102 right-sided ACD and 65 (95.6%) of 68 left-sided ACD cases that were diagnosed as grade I were treatable as outpatients. Conclusions: US can select patients eligible for outpatient therapy, and ACD patients with grade I are allowed to be treated as outpatients.

Keywords

• acute colonic diverticulitis (acd)
• abdominal sonography
• ct scan
• outpatients