Value of Magnetic Resonance Cholangiopancreatography in Assessment of Nonanastomotic Biliary Strictures after Liver Transplantation

Abstract

Background. Nonanastomotic biliary strictures (NAS) remain a frequent complication after orthotopic liver transplantation (OLT). The aim of this study was to evaluate whether magnetic resonance cholangiopancreatography (MRCP) could be used to detect NAS and to grade the severity of biliary strictures. Methods. In total, 58 patients after OLT from 2 Dutch transplantation centers in whom endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography and MRCP were performed within less than 6 months apart were included in the study. Of these patients, 41 had NAS and 17 were without NAS based on endoscopic retrograde cholangiopancreatography or percutaneous transhepatic cholangiography and follow-up. Four radiologists—2 from each center—used an adapted validated classification—termed “Leiden Biliary Stricture Classification” “(LBSC)—to evaluate the MRCP examinations independently. In this classification, NAS severity is assessed in 4 hepatobiliary regions. Interobserver agreement of the severity score for each region was calculated with the κ statistics. Results. Optimal cutoff value of the LBSC to detect the presence of NAS with MRCP was calculated at 3 points or greater for all readers. Applying this cutoff sensitivity for each reader was greater than 90%, with a specificity of 50% to 82%, positive predictive value of 86% to 91%, and negative predictive value of 80% to 100%. The MRCP performance was better in evaluation of the intrahepatic than of the extrahepatic bile ducts. The additional value of MRCP for grading severity of NAS was limited. Conclusions. The MRCP with the LBSC is a reliable tool to detect or exclude NAS after OLT. Currently, MRCP cannot be used to reliably grade the severity of these strictures.