CT and MRI of siderotic regenerating nodules in hepatic cirrhosis.

The demonstration by CT of siderotic regenerating liver nodules in cirrhosis was evaluated and compared with that of MR imaging retrospectively in 27 patients with histologically diagnosed hepatic cirrhosis. Only in one of the two patients with marked iron deposits in regenerating nodules did CT demonstrate multiple high density nodules. In the other patient with marked iron deposits and in seven of the nine patients with moderate iron deposits, the liver parenchyma on CT was demonstrated as heterogeneous and of slightly high density without focal nodules. In 8 patients with mild to moderate iron deposits and in the 10 with no iron deposits, the liver parenchyma was homogeneous on CT. Multiple low intensity nodules in the liver were seen on fast low-angle shot (FLASH) MR images in all 17 patients with iron deposits in regenerating nodules. No low intensity nodules were seen on FLASH MR images in the 10 patients with no iron deposits. If there are iron deposits above a certain level, siderotic regenerating nodules may appear as nodules of high density on CT or as heterogeneous regions of high density liver parenchyma. Magnetic resonance is more sensitive than CT in demonstrating siderotic regenerating nodules.