Biliary complications after liver transplantation: evaluation with MR cholangiography and MR imaging at 3T device

Purpose: To assess the diagnostic value of MR cholangiography (MRC) and MR imaging at 3T device when evaluating biliary adverse events after liver transplantation. Material and Methods: A series of 374 MRI examinations in 232 liver transplant subjects with suspected biliary complications (impaired liver function tests and/or biliary abnormalities on ultrasound) were performed at 3T device (GE-DISCOVERY MR750; GE Healthcare). After the acquisition of axial 3D dual-echo T1-weighted images and T2-weighted sequences (propeller and SS-FSE), MRC was performed through coronal thin-slab 3D-FRFSE and coronal oblique thick-slab SSFSE T2w sequences. DW-MRI of the liver was also performed using an axial spin-echo echo-planar sequence with multiple b values (150, 500, 1000, 1500 sec/mm2) in all diffusion directions. Contrast enhanced-MR cholangiography was performed in 25/232 patients. All MR images were blindly evaluated by two experienced abdominal radiologists in conference to determine the presence of biliary complications, whose final diagnosis was based on direct cholangiography, surgery and integrating clinical follow-up with ultrasound and/or MR findings. Results: In 113 patients no biliary abnormality was observed. The remaining 119 subjects were affected by one or more of the following complications: non anastomotic strictures including typical ischemic-type biliary lesions (n=67), anastomotic strictures (n=34), ampullary dysfunction (n=4), anastomotic leakage (n=4), stones, sludge and casts (n=65), vanishing bile duct (n=1). The sensitivity, specificity, PPV, NPV and diagnostic accuracy of the reviewers for the detection of all types of biliary complications were 99%, 96%, 95%, 99% and 97%, respectively. Conclusion: MR cholangiography and MR imaging at 3T device are reliable for detecting biliary complications after liver transplantation