Usefulness of the tensile gallbladder fundus sign in the diagnosis of early acute cholecystitis.

Abstract

The purpose of this article is to evaluate the usefulness of the tensile gallbladder fundus sign on CT in diagnosing early acute cholecystitis. The tensile gallbladder fundus sign on CT is defined as the absence of gallbladder fundus flattening by the anterior abdominal wall due to increased gallbladder pressures. Between October 2010 and March 2012, 222 patients with confirmed diagnoses of acute cholecystitis by surgery or follow-up imaging studies underwent CT scans in the emergency department because of right upper quadrant pain. Two radiologists retrospectively reviewed all CT images to determine the presence of the tensile gallbladder fundus sign and other CT findings previously reported to be suggestive of acute cholecystitis. Diagnostic performances were calculated and analyzed using pairwise comparisons of receiver operating characteristic curves. The kappa statistic was calculated to evaluate the interobserver agreement. Using the diagnostic criteria in which acute cholecystitis is defined as the presence of three or more classic CT findings, the addition of the tensile gallbladder fundus sign increased the area under the receiver operating characteristic curve (Az) value from 0.693 to 0.739 (p = 0.003). In the subgroup of 91 patients with no other CT features suggestive of acute cholecystitis, the sensitivity, specificity, and Az value of the tensile gallbladder fundus sign for acute cholecystitis were 74.1%, 96.9%, and 0.855, respectively. Interobserver agreement was good with the tensile gallbladder fundus sign (κ = 0.721). The tensile gallbladder fundus sign may be useful for diagnosing acute cholecystitis, especially in the early stage when other CT findings are absent.