MR Imaging Differentiation of Soft-Tissue Hemangiomas from Malignant Soft-Tissue Masses

The purpose of this study was to determine whether MR imaging features can reliably distinguish hemangiomas from malignant soft-tissue masses. We retrospectively reviewed MR imaging studies of 22 patients with soft-tissue hemangiomas and 22 patients with malignant soft-tissue masses. Images were reviewed and agreement reached by a consensus interpretation of two observers and by an independent observer. Masses were evaluated for signal intensity on T1- and T2-weighted images, for enhancement with gadolinium administration, and for morphology (lobulation, septation, central low-intensity dots). Lesion T2 signal and lesion enhancement with gadolinium administration were also objectively measured using regions of interest and comparison with skeletal muscle. Signal intensity on T1-weighted imaging of hemangiomas and malignant soft-tissue masses was similar. Subjective analysis showed greater T2 signal and gadolinium enhancement in hemangiomas; however, the differences were not statistically significant on objective analysis. Lobulation, septation, and central low-signal-intensity dots were all more common in hemangiomas, with statistical significance achieved; the combination of all three findings was specific for hemangioma. Although no single MR imaging feature was diagnostic in this study, analysis of lesion morphology, signal intensity, and enhancement with gadolinium allowed MR imaging differentiation of hemangiomas from malignant soft-tissue masses.