Fig. 10.

Gallbladder fossa abscess (*) observed after open cholecystectomy converted from laparoscopic cholecystectomy because of gallbladder perforation and intraperitoneal spillage of infected bile, sonographically (a) seen as ovoid well-demarcated infrahepatic collection with inhomogeneous hypo-anechoic structure. Unenhanced (b) and post-contrast (c) CT images confirmed abscess collection occupying the surgical bed, with predominantly fluid content, non-dependent air and thin enhancing peripheral wall. The faintly calcific fragment (arrow in c) corresponded to a dropped gallstone. Percutaneous CT-guided drainage was required to relieve extended-spectrum beta-lactamase-producing (ESBL+) Escherichia coli infection. (Partially reproduced from Open Access ref. [43])