Malignant hilar and perihilar biliary obstruction:: Use of MR cholangiography to define the extent of biliary ductal involvement and plan percutaneous interventions

PURPOSE: To determine the usefulness of magnetic resonance (MR) cholangiography in defining the extent of biliary ductal involvement in patients with malignant hilar and perihilar biliary obstruction and to evaluate whether findings at MR cholangiography alone are sufficient to plan percutaneous interventions in these patients. MATERIALS AND METHODS: Twenty-nine patients with malignant hilar and perihilar biliary obstruction were examined with MR cholangiography. Two radiologists evaluated MR images and determined the extent of biliary ductal involvement. A hypothetical plan for biliary drainage was established prior to any intervention. All patients underwent percutaneous cholangiography, and 27 of 29 patients also underwent biliary drainage and/or stent placement within 7 days after MR cholangiography. By using direct cholangiography as the standard of reference, the usefulness of MR cholangiography in defining the extent of biliary ductal involvement was determined. The type of drainage performed was compared with the type that had been anticipated at MR cholangiography. RESULTS: MR cholangiography was adequate in helping predict the extent of biliary ductal involvement in 28 (96%) of 29 patients and led to underestimation of the extent of the disease in one patient. The therapeutic plan anticipated with MR cholangiography matched the one actually used in 24 (83%) of 29 patients. CONCLUSION: The high accuracy of MR cholangiography for defining extent of ductal involvement in patients with malignant hilar and perihilar obstruction allows adequate planning of percutaneous interventions in a majority of patients.