Angiosarcoma of the liver: MR imaging pre- and post-chemotherapy.

Angiosarcoma of the liver is a rare tumor of mesenchymal origin. We report the MR appearance of angiosarcoma of the liver on T1-weighted, T2-weighted, and serial gadolinium enhanced spoiled gradient echo images pre- and post-intravenous chemotherapy. On pre-treatment images, angiosarcoma lesions were well defined, high signal with central regions of low signal on T2-weighted images, and showed peripheral nodular enhancement on serial post gadolinium images. Lesions resembled hemangiomas, however low signal central regions on T2-weighted images was a distinguishing feature. Post-treatment images acquired 11, 15, and 17 months after initiation of therapy, demonstrated decrease in diameter or resolution of angiosarcoma masses. Lesions increased in signal on T1 weighted images and decreased in signal on T2 weighted images approaching the signal intensity of liver. Treated liver lesions enhanced negligibly on gadolinium enhanced images.