Applied Radiology

Diagnosis

Hemangioma

Findings

One of the more characteristic lesions isdemonstrated in MRI dynamic contrast imaging. The lesion is of low signal intensity on images with T1 weighting. There is the obvious demonstration of initial nodular peripheral enhancement with eventual complete fill-in.

Discussion

A hepatic hemangioma is pathologically desribed as a tumor of numerous vascular channels with a supporting fibrous stroma. Hemangiomas are the most commonly occurring benign liver lesions, with an incidence of anywhere between 1 and 20%. There is an approximate 5:1 Female predominance, with many of the cases occurring in postmenopausal women. Imaging evaluation of hemangiomas can be undertaken by Nuclear Medicine, CT, Ultrasound and MRI. Tagged red cell Nuclear Medicine imaging can be rather specific for hemangioma, given the early phase photopenia with eventual prolonged fill-in of the tumor. While other vascular lesions can also demonstrate this prolonged activity, early uptake is the rule with most. The classic ultrasound appearance of a hemangioma is diffuse hyperechogenicity with slight increased through transmission. The CT appearance of hemangioma consists of a well demarcated hypodense lesion with somewhat nodular borders. Contrast enhancement results in peripheral to central fill-in. There may be a central, non-enhancing region as a result of fibrosis. Calcification can be seen in between 10 and 20% of lesions. The MRI diagnosis of hemangioma is similar to CT with post Gadolinium images demonstrated initial nodular peripheral enhancement with subsequent fill-in. They also demonstrate significant high signal on T2 weighted images, but intermixed with lower signal areas as a result of the fibrous stroma.

Gore, Levine, Laufer. Textbook of Gastrointestinal Radiology. W.B. Saunders Company, Philadelphia, 1994.