Preoperative imaging of biliary tract cancers.

Many imaging techniques are available for the evaluation of patients with malignant obstructive jaundice. Ultrasonography, in experienced hands, is valuable for evaluating the local extent of the disease, but its usefulness for staging distant metastases is limited. When used properly, CT and MR imaging can provide valuable information about the extent of local tumor involvement and distant metastases. These noninvasive techniques provide images of the bile ducts and vascular images that are comparable in quality to those obtained with more invasive procedures, such as PTC, ERCP, and angiography, and do not have the risk for complications of these invasive techniques.