US Characterization of Soft Tissue Hemangiomas of Extremities: Correlation with MR Signal Intensity

ABSTRACT

PURPOSE: To evaluate the US findings of soft tissue hemangiomas in extremities and to correlate the echo-pattern with MR signal characteristics of hemangiomas. MATERIALS AND METHODS: We retrospectively studied forty-two patients either with pathologically proven cases or with characteristic features of hemangiomas on MRI, US and plain film. Hemangiomas were divided into two types according to the locations;subcutaneous and intramuscular. Analytic points on US and MR findings were gross morphology of the mass, internal echo-pattern or signal characteristics. We correlated the echo-pattern with MR signal characteristics in hemangiomas. RESULTS: Subcutaneous hemangiomas revealed homogeneously anechoic mass on US, which were well correlated with MR signal characteristics' homogeneous low singnal intensity(SI) on Tl-weighted image(WI) and high SI on T2-WI. Intramuscular hemangiomas showed heterogeneously mixed echoic masses on US. An anechoic component on US corresponded to dilated vascular channels on MRI. The signal intensity of intramuscular hemangioma was less than that of subcutaneous fat on T1-WI and greater than that of fat on T2-WI. Both types of hemangiomas had tubular or lace-like appearance with interspersed fibrofatty septa. CONCLUSION: The echo-patterns in US were well associated with MR signal characteristics on MRI. Regarding US and MR features, intramuscular hemangiomas were different to subcutaneous hemangiomas.