Magnetic resonance cholangiopancreatography evaluation of intrahepatic bile duct variations with updated classification.

PURPOSE Preoperative detection of intrahepatic bile duct (IHBD) variations is essential to reduce surgical morbidity and mortality rates. Magnetic resonance cholangiopancreatography (MRCP) is a noninvasive and reliable method for demonstrating the normal IHBD anatomy and its variations. This retrospective study aimed to identify and classify novel variations, except those already reported in the literature, using MRCP. METHODS MRCP examinations, which were conducted in two different centers in the last five years, were retrospectively evaluated. IHBD variations were recorded with respect to the Yoshida classification. In addition, newly detected variations that were not included in this classification were identified and classified. RESULTS MRCP examinations of 2624 patients were screened, and 2143 were determined to be eligible for evaluation. Of 2143 patients, 987 were males (average age, 54±18 years) and 1156 were females (mean age, 57±17 years). In this study, 10 novel variations that were not included in the Yoshida classification were identified in 14 patients. CONCLUSION MRCP is an effective, reliable, and noninvasive imaging method for evaluating the IHBD anatomy and its variations. Novel variations described in this study may help to better understand the biliary anatomy.