Biliary obstruction: Findings at MR cholangiography and cross-sectional MRimaging

Twenty-two patients with malignant biliary obstruction and 21 patients with suspected obstruction of biliary-enteric anastomoses were evaluated over a 12-month period with magnetic resonance (MR) cholangiography and cross-sec tional MR imaging. In patients with malignant obstruction, MR cholangiograp hy helped accurately determine the status of the biliary ductal system by i dentifying the exact location and extent of the obstruction and the severit y of duct dilatation. In so doing, MR cholangiography helped determine whet her percutaneous transhepatic cholangiography with antegrade stent placemen t or retrograde cholangiography with stent placement constituted the more s uitable treatment. Cross-sectional MR imaging was necessary to identify the organ of tumor origin, define the tumor margins, and determine the stage o f disease. This information helped evaluate the appropriateness of curative surgical therapy versus palliative drainage procedures. In patients with b iliary-enteric anastomoses, MR cholangiography clearly depicted the site of the anastomosis and demonstrated the status of the intrahepatic ducts, the reby helping determine which patients would benefit from undergoing antegra de duct cannulation with a drainage procedure or perhaps balloon dilation. In some of these patients, MR cholangiography was sufficient to help plan t herapeutic intervention. MR cholangiography also demonstrates the presence and size of biliary stones and associated findings such as intraductal tumo r growth. In addition, MR cholangiography may obviate retrograde cholangiog raphy, which can be technically difficult to perform.