Role of diffusion and perfusion-weighted MR imaging in differentiating meningioma from solitary dural metastasis

In some instances conventional imaging techniques fail to differentiate meningiomas from isolated dural metastasis. This study aimed to evaluate the role of diffusion and perfusion-weighted MRI in differentiating meningiomas and dural metastasis. In this study, 14 metastasis and 26 meningiomas were involved. The imaging characteristics were analyzed using conventional MRI. Diffusion-weighted MRI was performed and ADC values were calculated from the solid components and the peritumoral edema. Perfusion-weighted MRI was performed and relative cerebral blood volume (rCBV) was calculated. Student's t test was used for the statistical analysis. Dural metastasis and meningiomas could not be differentiated by qualitative assessment of conventional and diffusion-weighted MRI. The mean intratumoral and peritumoral ADC values were not statistically significant (p > 0.05). The rCBV ratios for dural metastasis and meningiomas were 4.13 ± 2.32 and 7.32 ± 4.10 respectively and the difference between two was statistically significant (p = 0.003). Peritumoral rCBV ratios for dural metastasis and meningiomas were not statistically significant (p > 0.05). Conventional MRI findings of dural metastasis and meningiomas may overlap in some lesions. In differentiation of these lesions diffusion-weighted MRI yields no further information additional to conventional sequences. Perfusion-weighted MRI can be useful to distinguish these lesions by demonstrating high intratumoral rCBV ratios for meningiomas and low rCBV ratios for metastasis.