Abstract
For MR evaluation of carcinoma of the biliary system, MR cholangiography (MRC) and 3D dynamic study are the two main sequences to be used, both of which are based on excellent contrast resolution. Usually, overall view of the whole biliary system is first obtained with MRC, and then, conventional MR sequences including 3D dynamic study are applied to scrutinize the pathologic sites (stenosis, obstruction, etc) as observed on MRC. Both 3D and 2D MRC may be used. Dynamic study is to be obtained with fat suppression and along the plane with which the target lesion is best visualized. Diffusion-weighted image is a novel and promising tool, however, its validity is yet undetermined. In gallbladder carcinoma, delayed subserosal enhancement on the dynamic study may be a useful sign to suggest subserosal invasion of carcinoma, which would make MR superior to MDCT. In bile duct carcinoma, MR may provide more useful information for lesion characterization than MDCT. MR/MRC is a useful modality to assess carcinoma of the biliary system and should be used in addition to MDCT.
