Computed tomography of the bile ducts.

Although not typically a first-line test for patients with suspected biliary tract disease, improvements in CT technology have resulted in an increased ability for CT to detect and characterize causes of biliary obstruction and other biliary diseases. As with other abdominal neoplastic disease, CT is the most common imaging procedure for staging biliary tract malignancies. Attention to optimizing CT techniques and an awareness of subtle CT imaging findings can increase the efficacy of CT in evaluating the biliary tract.