Pancreatobiliary Flow Dynamics: Association Between Bile and Pancreatic Juice Evaluated With Cine-Dynamic Magnetic Resonance Cholangiopancreatography Using Spatially Selective Inversion Recovery Pulse.

Background: The physiological flow patterns and the reciprocal relationship between pancreatic juice and bile excretion dynamics have not been clearly elucidated by imaging.

Purpose: To assess the physiological flow patterns of bile and pancreatic juice simultaneously in order to clarify the pancreatobiliary flow dynamics using cine-dynamic magnetic resonance cholangiopancreatography (MRCP) with a spatial selective inversion recovery (IR) pulse.

Study Type: Retrospective.

Population: A total of 85 patients with physiologically normal pancreatobiliary flow without ductal dilatation (normal group) and 19 patients with dilated pancreatic duct.

Field Strength/sequence: A 3 T, fast spin echo sequence with IR pulse to nullify the signal of static pancreatic juice and bile.

Assessment: The frequency and secretion grade of the antegrade and reverse flow of the pancreatic juice and bile on cine-dynamic MRCP were visually evaluated. Additionally, the reciprocal relationship between pancreatic juice and bile flow was evaluated based on its flow patterns.

Statistical Tests: Spearman's rank correlation coefficient analysis and the Kruskal-Wallis and Mann-Whitney U tests were used. P values of <0.05 were considered to indicate statistical significance.

Results: In the normal group, the antegrade pancreatic juice flow and no bile flow pattern was most frequently observed (29%), followed by the no pancreatic juice flow and no bile flow pattern (23%), the antegrade pancreatic juice flow and antegrade bile flow pattern (22%), and the no pancreatic juice flow and reverse bile flow pattern (9%). The flow of the pancreatic juice and bile were synchronized with each other in 47%, while they were not in 53%. In the dilated pancreatic duct group, the mean secretion grade of the antegrade bile and pancreatic juice flow was significantly lower than in the normal group.

Data Conclusion: Cine-dynamic MRCP with a spatially selective IR pulse can visualize the variations of the physiological flow patterns of bile and pancreatic juice including 53% of unsynchronized patterns.

Level Of Evidence: 4 TECHNICAL EFFICACY: Stage 5.