Figure 6a. Primary hepatic carcinoid tumor. (a) Coronal T2-weighted MR image shows a large solid mass in the right lobe of the liver. The mass contains a small area of high signal intensity (arrow) that is indicative of necrosis. At histologic analysis of a biopsy specimen, the mass was proved to be a poorly differentiated carcinoid tumor. After careful evaluation, it was determined that the liver was the primary site of disease. (b) Coronal, axial, and sagittal images from FDG PET in the same patient show the large solitary hepatic mass. (c) Axial gadolinium-enhanced T1-weighted MR image from another patient demonstrates a tumor with peripheral and septal enhancement.