Evaluation of biliary anatomy in the caudate lobe using drip infusion cholangiography-computed tomography.

PURPOSE: This study aimed to retrospectively evaluate the caudate branches (CBs), which are bile ducts originating from the caudate lobe (CL), using drip infusion cholangiography with computed tomography (DIC-CT).

METHODS: The confluence patterns of CBs were evaluated in 185 adult patients undergoing DIC-CT. The following bile duct features were evaluated: (a) number of depicted CBs; (b) identification of the caudate portion from which the CBs were derived; (c) identification of the confluence site of a CB; and (d) whether there was a difference in the confluence site of the CBs depending on the position of the right posterior hepatic duct (RPHD) and the portal vein (PV).

RESULTS: DIC-CT enabled detection of a total of 640 bile ducts from the CL in 185 patients, and the total number of CBs from the Spiegel lobe (SP), the paracaval portion, and the caudate process (CP) were 347 (54.2%), 112 (17.5%), and 181 (28.2%), respectively. In the SP, over 60% of CBs joined the left hepatic duct system (LHDS). The positional relationship between the RPHD and the PV was divided into a supra-portal course (n = 168) and an infra-portal course (n = 17). The number of CBs joining the LHDS was significantly different between a supra-portal course and an infra-portal course (p = 0.0484).

CONCLUSION: CBs were depicted by DIC-CT in 98.9% of the subjects, and a detailed evaluation was possible. The number of CBs joining the LHDS was associated with the position of the RPHD and the PV.