Analysis of Peritumoral Edema in MRI of Meningioma

ABSTRACT

PURPOSE: The purpose of this study is to evaluate the incidence and the degree of peritumoral edema on MRI in meningioma and to correlate other MR findings with the edema. MATERIALS AND METHODS: MR images of 35 patients with histologically-confirmeal meningioma were retrospectively reviewed. We analyzed the MR findings with special attention to the presence or absence and degree of edema. The edema was graded as absent, mild (extending less than 1 cm from outer margin of mass), moderate (1 to 3cm with mild mass effect), and severe (more than 3cm with marked mass effect). We also evaluated size and margin of the tumor, heterogeneity of mass signal, enhancement pattern and dural enhancement of the masses. In 24 patients with cerebral angiography, cerebral vascularity on angiogram was correlated with MR findings. Statistic correlation analysis was done using SAS ver 6.04. RESULTS: Twenty-five of 35 cases (72%) had edema; mild in 11 cases, moderate in 10 cases, and severe in 4 cases. Heterogeneous signal intensity of mass (0.05), dural enhancement (>0.05), and histologic type (>0.05) were not correlated with edema. CONCLUSION: In meningioma, moderate to severe peritumoral edema occurred in 41% (14/35). The edema was correlated with heterogeneous enhancement, size, location, heterogeneous signal intensity and vascularity of the mass on angiography.