MR and MR angiography characterization of soft tissue vascular malformations.

Hemangioma is an abnormal proliferation of blood vessels that may occur in any vascularized tissue. Different classifications separate vascular lesions of soft tissues into hemangiomas and vascular malformations on the basis of their natural history, location, cellular turnover, and histology. Soft-tissue vascular malformations are relatively common. These lesions can be categorized on MR imaging because of their typical appearance as multiple lobules with fat overgrowth and serpentine channels, depending on the vascular flow. The combination of conventional MR and MR angiography (MRA) enable the differentiation between low-flow and high-flow vascular malformations and allows a noninvasive diagnostic strategy. This article reviews the MR and MRA imaging characteristics of soft-tissue hemangiomas to provide a helpful guide for radiologists to perform a more specific diagnosis and better management of these anomalies.