CT and MR appearance of focal nodular hyperplasia of the liver in children with biliary atresia.

Two children with biliary atresia are described in whom focal nodular hyperplasia of the liver occurred following portoenterostomy. The lesions were low-or iso-dense on unenhanced CT and became hypodense post-contrast enhancement. There was normal 99mTc phytate on hepatic colloid scintigraphy. On T2-weighted spin echo MR images, there was increased signal intensity within the masses, and the surrounding liver parenchyma was divided by linear septa in one of the two cases.