Figure 2. Magnetic resonance cholangiopancreatography (A) and selected axial magnetic resonance images (B–D) demonstrating an ampullary-based mass located within the lumen of the second part of the duodenum (*). The common bile duct (arrow) and the pancreatic duct (long arrow) are normal. The mass had a moderate signal on T2-weighted image (B). Enhancement of the mass in the arterial phase (C) and washout in the venous phase (D) are seen.