Magnetic resonance-assisted imaging of slow flow in the pancreatic and common bile duct in healthy volunteers

Abstract

Background: Magnetic resonance cholangiopancreaticography (MRCP) is commonly used to evaluate the pancreatic (PD) and common bile duct (CBD), and the addition of secretin is used to obtain functional information (S-MRCP). Neither method gives any information on flow velocities within the ducts. Purpose: To evaluate a new, MRI diffusion-based, slow-flow-sensitive sequence for the detection of slow flow changes in the PD and CBD. Material and Methods: Seven healthy volunteers were examined. A modified single-shot turbo spin-echo sequence was used to detect slow flow changes. Three b factors (0, 6, and 12 s/mm2) were used. The flow sensitivity was applied in two directions, vertically and horizontally. Scanning was performed before and after glucagon was given, and again after an intravenous injection of secretin. The sequence gives signal loss from a duct when flow increases, and such changes were recorded. Results: All images showed the PD with b = 0 (no flow sensitization). After administration of glucagon, artifacts from bowel movements were reduced and visibility of the PD was improved at both b = 6 and b = 12. Significant reduction of the visibility of the PD, indicating increased flow, was recorded both at b = 6 and b = 12 after the administration of secretin. There were no changes in the visibility of the CBD. Conclusion: This study shows that MRI-based detection of slow flow changes inside the PD is possible. Due to the sequence’s high sensitivity to any motion, further studies are required before adopting the method for clinical use.