Visceral CT findings associated with Thorotrast

Plain radiography and CT of the abdomen were reviewed in four patients who had undergone angiography with thorium dioxide (Thorotrast). In three patients CT showed irregularly scattered focal punctate collections of Thorotrast in the liver parenchyma, predominantly in the subcapsular zone, associated with areas of low or nonhomogeneous attenuation. These areas of low attenuation were identified on microscopic studies as sites of hepatic fibrosis or neoplasia. Computed tomography identified intrahepatic Thorotrast deposits more definitively than plain radiography.