Digital Subtraction Imaging in the Hepatopancreatobiliary Field

[Background] Digital subtraction imaging (DSI) is a radiological technique widely employed to enhance visualization by eliminating background structures. [Objective] This study retrospectively analyzed 11 cases in which DSI was applied to hepatobiliary and pancreatic interventions at our institution between 2021 and 2025. These cases included two cases of route selection in ERCP for patients with reconstructed gastrointestinal anatomy, two cases of preoperative pancreatic duct imaging, and seven cases of hilar bile duct stricture evaluation. [Methods] DSI sequences were acquired using Ultimax-i DREX-U180 (Canon, Japan). DSP (Digital Subtraction Pancreatography) and CDDSC (CO2 Digital Subtraction Cholangiography) were performed with amidotrizoic acid or carbon dioxides infusion. CDDSE (CO2 Digital Subtraction Enterography) was employed to improve route selection by enhancing afferent loop visualization in patients with reconstructed anatomy. DSP and CDDSC were assessed for their ability to depict secondary duct branches, while CDDSE was evaluated for afferent loop clarity. [Results] The elimination of vertebral structures allowed DSP to clearly depict secondary branches of the pancreatic ducts. In contrast, CDDSC failed to visualize secondary biliary branches in 3 of 7 cases. CDDSE successfully enhanced afferent loop visualization in 2 cases. No procedural complications occurred in any case. The mean total radiation dose was 31.4 mGy. [Conclusion]The ability of digital subtraction techniques to eliminate vertebral and intestinal gas interference may enhance procedural accuracy and outcomes.