Strategies for imaging biliary neoplasms

Biliary tract neoplasms are rare, develop in either intra- or extrahepatic locations, and are represented by a spectrum of imaging characteristics. These tumors may be imaged using a variety of traditional methods, such as ERCP, PTC, ultrasound, or CT, and some newer innovative cross-sectional techniques, such as MR- or CT-cholangiography. The choice of imaging technique depends on whether the study is for diagnostic, staging, or therapeutic purposes. Because these tumors are frequently small, secondary features such as intrahepatic ductal dilatation or even hepatic metastases, may be the initial finding on screening studies. Benign tumors, postsurgical strictures, or even biliary sludge may mimic features of malignant tumors, and the radiologist must be aware of these potential sources of interpretative error.