Purpose: To determine MR features suggestive of mass-forming cholangiocarcinoma (CCA) or liver metastases of adenocarcinoma of unknown primary (AUP), and to compare the ability of two experienced radiologists to establish the correct diagnosis.
Materials And Methods: 61 patients with CCA or AUP, with MRIs were placed into two groups: population 1, 28 patients with certain diagnosis of either CCA or AUP; and population 2, 33 patients with uncertain diagnosis. Using population 1 with known diagnosis, two investigators formulated imaging criteria for CCA or AUP, which represented phase 1 of the study.