Visualization of pancreaticobiliary reflux in anomalous pancreaticobiliary junction by secretin-stimulated dynamic magnetic resonance cholangiopancreatography

PURPOSE: To assess the utility of secretin-stimulated dynamic MR cholangiopancreatography (MRCP) for the visualization of pancreaticobiliary reflux in patients with anomalous pancreaticobiliary junction (PBJ). MATERIAL AND METHODS: Ten controls and seven patients diagnosed as having anomalous PBJ were prospectively examined by dynamic MRCP after secretin injection using a breath-hold, single-shot turbo spin-echo T2-weighted sequence. The optimal MRCP section was repeated 35 times at approx. 10-second interval after secretin injection; the acquisition time was 4 s per image. The signal intensity (SI) changes of the extrahepatic and intrahepatic bile ducts, presence or absence of intraluminal signal void, caliber change of the bile duct, duodenal filling, and peak time of the SI ratio of the extrahepatic bile duct after secretin injection were compared between the controls and patients. RESULTS: In the controls, the extrahepatic and intrahepatic bile ducts showed neither enhancement nor caliber change over the observation period, providing no apparent peak time. Of the seven patients, the extrahepatic bile duct showed retrograde enhancement and sequential delay in occurrence of the peak time from its distal third to its proximal third (n = 6) with a signal void in its distal part (n =4); its caliber increased subsequently to pancreatic secretion (n = 5); the intrahepatic bile ducts showed a slight enhancement following SI increase of the proximal extrahepatic bile duct (n = 6); duodenal filling grade tended to be lower in the patients than volunteers (P<.005). CONCLUSION: In patients with anomalous PBJ pancreaticobiliary reflux were demonstrated by dynamic secretin-stimulated MRCP.