Hereditary tyrosinaemia (HT) type 1A.

Two infants, aged 5 and 6 months, with the chronic form of HT Type 1 A were studied with sonography and CT. The imaging findings mirrored the pathological process. The sonographic findings included marked hepatomegaly, the parenchyma being of increased echogenicity due to fibrosis and fatty infiltration, and containing multiple hypoechoic regenerating nodules of varying sizes. There was marked nephromegaly, with uniform thickening of the renal cortices. Apart from the density measurement of the hepatic nodules and the perfusion status of the liver and kidney, no additional information was added by CT imaging. The diagnosis of HT Type 1 A should be excluded in an infant presented with the described typical sonographic features.