Correlative CT, MRI and histological findings of hepatic Echinococcus alveolaris: a case report.

Diagnosis of liver infestation by Echinococcus alveolaris (EA) is based on serologic, sonographic and CT findings. Literature review yielded only one report discussing the MRI findings of hepatic EA infestation. In this report, we present a case of hepatic EA infestation with its correlative CT, MRI and histological findings. CT showed hypodense mass involving more than half of the liver with rim and central calcifications. MRI revealed hypointense signal of the infiltrative mass on both T1- and T2-weighted images. On MRI, the portal vein branches were seen coursing through the lesion. Neither CT nor MRI demonstrated any contrast enhancement of the mass. On the histological examination, abundant fibrous and hyalinized tissue surrounding multiple small cysts were observed. MRI may provide invaluable information in the diagnosis of EA infestation of the liver, either by disclosing the infiltrative pattern of infestation without significant effect to vascular structures, or by the signal characteristics.