Multimodality approach to detection and characterization of hepatic hemangiomas
Hemangiomas are the most common benign hepatic tumor and represent a common incidental finding on routine imaging examinations of the liver. The majority of hemangiomas demonstrate classical imaging findings on grayscale ultrasound (US), multidetector-row computed tomography (MDCT), and magnetic resonance imaging (MRI). The classic appearance on contrast-enhanced cross-sectional imaging is that of centripetal nodular enhancement with progressive fill-in of the lesion over time with conventional extracellular CT and MR contrast agents. With the advent of new gadolinium-based MR contrast agents such as hepatocyte-specific contrast agents and blood pool contrast agents, some different appearances of hemangiomas are possible and familiarity with these appearances is critical in making the correct diagnosis. There are also variants of the typical hemangioma, including the flash-filling hemangioma, giant hemangioma, sclerosed or hyalinized hemangioma, as well as hemangiomas occurring on a background of hepatic steatosis and cirrhosis. Again, knowledge of these variant types of hemangiomas can prevent against misdiagnosis of these lesions in the clinical setting.