Computed tomography findings of ceftriaxone-associated biliary pseudocholelithiasis in adults

Purpose This study aimed to characterize the computed tomography (CT) findings of pseudolithiasis and investigate the outcomes and natural history in adult patients receiving CTRX therapy. Methods A total of 17 patients were diagnosed with CTRX-associated biliary pseudolithiasis on CT between April 2013 and March 2017. The medical records, characteristics, complications, treatment options, and outcomes of these patients were examined. Serial CT images and the form, density, and location of pseudolithiasis were reviewed by two radiologists. Results Of the 17 patients with CTRX-associated pseudolithiasis, seven were men and ten were women. The median patient age was 78 years (range 31–88 years). The median interval from CTRX administration to the diagnosis of pseudolithiasis was 10 days (range 4–32 days). The CT findings of pseudolithiasis included a sludge pattern (11 patients [64.7%]), stone pattern (two patients [11.8%]), and stone plus sludge pattern (four patients [23.5%]). Seven patients (41.2%) showed gall bladder enlargement along with a common bile duct (CBD) stone. Two patients with CBD stones underwent endoscopic CBD stone removal. The median time to pseudolithiasis resolution after CTRX cessation was 69 days. Conclusion The high-density sludge pattern is the most common typical CT finding of CTRX-associated pseudolithiasis in adults.