Imaging features of hepatic angiomyolipoma on CT and MRI

Abstract

Objective To analyze the imaging features of hepatic angiomyolipoma (HAML) on computed tomography (CT) and magnetic resonance imaging (MRI). Methods The imaging fingdings of 18 tumors which were pathologically diagnosed as HAML after surgery were analyzed retrospectively. Before operation, twelve and ten patients underwent CT and MRI non-contrast and dynamic enhanced scans, respectively, and 4 patients received both examinations. The imaging characteristics including the number, diameter, location, appearance of the lesions, plain and dynamic enhancement mode were analyzed. Results Eighteen HAML lesions were found in 18 patients with a diameter ranging from 1.5 cm to 17.2 cm (mean 5.3 cm). Five lesions manifested fatty content, and one showed hemorrhage and necrosis. Five HAMLs enhanced in afast-in and fast-outmode, eleven in afast-in and slow-outmode and two other lesions in an irregularly discrete mode. The arterial supply was found in 11 HAMLs in the hepatic arterial phase, all coming from intrahepatic arteries. Intratumoral vessels were observed in 12 HAMLs. Early draining veins to the hepatic vein (n=3) and portal vein (n=1) were detected in 4 HAMLs. One lesion demonstrated delayed enhancement in the pseudocapsule. Conclusion The detection of arterial supply and intratumoral vessels in a hypervascular hepatic tumor on contrast CT and MRI in a patient with a non-cirrhotic liver and normal AFP helps to make a diagnosis of HAML. Key words: Hepatic angiomyolipoma; Tomography; Magnetic resonance imaging