Imaging bile duct tumors: staging

Cholangiocarcinoma (CC) is the most frequent neoplasm of the biliary system. According to its anatomic origin in the biliary tree it is usually classified as intrahepatic, perihilar, or extrahepatic distal CC. Tumors originated in these areas differ in biological behavior and management. The stratification of the patients aligned to therapeutic options and prognosis is a key point in the management of CC. Thus, specific staging systems have been designed for each anatomical location. They are precise for surgical planning, to establish prognosis after surgery, or to compare the benefits of different therapeutic approaches, but they are less accurate to stratify patients into a therapeutic decision algorithm. Imaging tools, mainly multidetector computed tomography and magnetic resonance imaging (MRI), allow full assessment of the diagnosis and extension of the tumor. They are especially useful in establishing the correct diagnosis and determining resectability, which reaches a high negative predictive value, identifying those patients in whom surgery will not be effective. We will discuss the different staging systems for CC, the radiologic characteristics with classical and recently described signs that allow a confident diagnosis of the disease and the criteria for resectability of biliary tract malignancies.