Hepatic hemangiomas in childhood: the spectrum of radiologic findings. A pictorial essay.

Hepatic hemangiomas (HHs) are the most common benign liver tumors in infancy, but despite their frequent occurrence, their radiologic appearance may be particularly challenging to assess, owing to unique anatomical and development features that distinguish their subtypes in the pediatric population. There are 3 main patterns of the lesions recognized in HHs: focal, multifocal and diffuse. Medical care strategies range from simple observation to surgery, and a timely diagnosis is crucial to establish the most appropriated clinical management and therapy. Ultrasound (US) is typically the first level examination of pediatric vascular anomalies, able to meet a satisfactory diagnosis and has proved very helpful to assess for involution through serial imaging. CT and MRI are second-level methods seldom performed, offering an anatomical panoramic view and clarification when US is non-conclusive. Histologic confirmation is rarely required. HHs show a variable sonographic appearance, with hypoechoic (mostly) or hyperechoic solitary\multifocal mass and wide features. Hepatic vessels assessment reveals an abnormal flow, enlarged vasa, decreased resistive index (RI) values, scarce blood supply distally to lesions and hyper vascular regions inside them. In this pictorial essay, we review HHs subtypes in further details, illustrate US, CT and MRI findings and clarify a recurrent dispute over the existing terminology.