Pancreatic duct: morphologic evaluation with MR cholangiopancreatography after secretin stimulation.

PURPOSE To evaluate the pancreatic duct after administration of secretin. MATERIALS AND METHODS Single-shot turbo spin-echo T2-weighted dynamic magnetic resonance cholangiopancreatography (MRCP) was performed in 85 patients who did not have pancreatic diseases (group 1) and in 50 patients who had focal severe stenosis of the main pancreatic duct (group 2). The visualization and diameter of the pancreatic duct before and after secretin administration were assessed. RESULTS In group 1, after secretin administration, the best visualization of the main pancreatic duct in the head, body, accessory pancreatic duct, and branch ducts was achieved in 4.7 minutes +/- 1.6 (SD), 4.8 minutes +/- 1.6, 4.6 minutes +/- 1.6, and 4.7 minutes plus minus 1.3, respectively. Improvement in the delineation of the main pancreatic duct in the head (78 [92%] patients), body (80 [94%] patients), accessory pancreatic duct (35 [41%] patients), and branch ducts (14 [16%] patients) was achieved. Overlap of fluid in the organ and the pancreatic duct was observed in 20 (24%) of 85 patients. Overlap was especially observed after 5 minutes of secretin injection. In group 2, the best visualization of the distal main pancreatic duct was achieved 4.9 minutes +/- 1.4 after secretin administration. Improvement in the delineation of the distal main pancreatic duct was achieved in 17 (85%) of 20 patients. CONCLUSION MRCP is best performed during the first 5 minutes after secretin administration.