Value of Magnetic Resonance Cholangiography in Benign and Malignant Biliary Stenosis: Comparative Study with Direct Cholangiography

PURPOSE: Magnetic resonance cholangiography (MRC) is currently under investigation for imaging of biliary stenosis. The purpose of this study was to evaluate the diagnostic value of MRC compared with direct cholangiography in biliary duct diseases, with the exception of biliary-enteric anastomosis. METHOD: Forty-nine patients (26 men, 23 women; median age 60 years) with clinically suspected bile duct stenosis were prospectively included. Magnetic resonance cholangiography was performed within 7 days before direct cholangiography, considered to be the gold standard. Stenosis location, extension, and type according to Bismuth classification as well as diagnostic presumed causes were determined by 2 radiologists and 1 endoscopist. RESULTS: Magnetic resonance cholangiography correctly identified the level of biliary ductal obstruction compared with direct cholangiography findings in 96% patients. Excellent agreement between MRC and direct cholangiography was found for the stenosis location (kappa value, 0.89). Sensitivity and specificity of MRC to detect common bile duct stenosis were 88% and 100%, respectively. Sensitivity and specificity of MRC to detect biliary confluence stenosis were 96% and 93%, respectively. Precise location of the lesion according to Bismuth classification was correctly evaluated on MRC in 74% of patients (kappa value, 0.64). The overall interobserver concordance between radiologists for the level of stenosis was good (kappa value, 0.625). In 35 patients with intrahepatic bile ducts dilation identified on direct cholangiography, 97% of patients were identified on MRC. Moderate concordance between MRC and direct cholangiography was confirmed in the evaluation of the surgical management (kappa value, 0.55). CONCLUSION: Magnetic resonance cholangiography is able to replace diagnostic direct cholangiography to restrict the use of invasive procedures to cases in which therapeutic procedures are anticipated or MRC findings are equivocal, especially in biliary tract diseases.