Analysis of peritumoral edema in MRI of meningioma

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. MR images of 35 patients with histologically confirmed meningioma were retrospectively reviewed. We analyzed the MR findings with special attention to the presence or absence and degree of edema. The edema was grade as absent, mild (extending less than 1 cm from outer margin of mass), moderate (1 to 3 cm with mild mass effect), and severe (more than 3 cm 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. Twenty five of 35 cases (72%) had edema; mild in 11 case, moderate in 10 cases, and severe in 4 cases. Heterogeneous signal intensity of mass (<0.001), heterogeneous enhancement of mass (<0.001). mass size (<0.001), location (<0.001), and vascularity on angiography (<0.05) were well correlated with edema, while mass margin (>0.05), dural enhancement (>0.05), and histologic type (>0.05) were not correlated with edema. In meningioma, moderate to severe peritumoral edema occurred in 41% (14/35). The edema was correlated with heterogenous enhancement, size, location, heterogeneous signal intensity and vascularity of the mass on angiography