MR cholangiopancreatography in patients with primary sclerosing cholangitis: Interobserver variability and comparison with endoscopic retrograde cholangiopancreatography

OBJECTIVE. The purpose of our study was to determine the degree of interobserver variability and correlation between MR cholangiopancreatography and endoscopic retrograde cholangiopancreatography (ERCP) for the presence of bile duct strictures in patients with primary sclerosing cholangitis. MATERIALS AND METHODS. For this retrospective study involving 26 patients with primary sclerosing cholangitis, 31 MR cholangiopancreatograms were compared with 30 endoscopic retrograde cholangiopancreatograms. The MR cholangiopancreatograms were independently interpreted by two abdominal radiologists in a blinded, randomized manner for overall image quality, extent of ductal visualization, and the presence and location of bile duct strictures. Unweighted multirater kappa coefficient values were estimated for each comparison. RESULTS. Visualization of more than 50% of the expected ductal length was possible in the extralrepatic, central intrahepatic, and peripheral intrahepatic bile ducts in 99%, 88%, and 69% of the MR cholangiopancreatograms and 100%, 86%, and 52% of the endoscopic retrograde cholangiopancreatograms, respectively. Strictures were detected in the extrahepatic, central, and peripheral ducts in 53%, 68%, and 87% of the MR cholangiopancreatograms and 73%, 67%, and 63% of the endoscopic retrograde cholangiopancreatograms, respectively. The interobserver agreement for stricture detection was 61% for MR cholangiopancreatography and 76% for ERCR MR cholangiopancreatographic findings were consistent with ERCP findings for the presence of strictures in 69% of the cases. CONCLUSION. In patients with primary sclerosing cholangitis, MR cholangiopancreatography better shows the bile ducts and can depict more strictures, especially of the peripheral intrahepatic ducts, than ERCR MR cholangiopancreatography can be used to noninvasively diagnose and follow up patients with primary sclerosing cholangitis.