Study of MR Diffusion Tensor for Meningiomas

Objective To evaluate the value of FA and ADC in the diagnosis of meningiomas.Materials and Methods 28 patients with meningiomas were underwent conventional MR and DTI before treatment. Tumor, edema, contralateral normal white matter and regions near the tumors were determined on T 2WI, contrast-enhanced T 1WI and FA images. Average diffusion coefficients (ADC) value, ADC maps, fractional anisotropy (FA) value and FA maps were calculated in areas which mentioned above.Results Grade Ⅰ meningiomas: ADC value in the edema was higher than that of tumor, the normal white matter around and opposite the tumors (P0.05). FA value in the contralateral normal white matter and regions near the tumors was higher than that of tumor and edema (P0.05), there were no significant difference in FA value between tumor and edema (P0.05). Grade Ⅱ+Ⅲ meningiomas: ADC value in the edema was higher than that of tumor, the white matter around and opposite the tumors (P0.05), the ADC value in tumors was also significant difference from the white matter around and opposite the tumors (P0.05). FA value in the white matter around the tumors was higher than that of tumor and edema (P0.05). The significant difference in ADC value were found in tumors,edema, and the white matter around tumors between gradeⅠand Grade Ⅱ+Ⅲ meningiomas (P0.05). FA in the white matter around tumors was also found significant difference between gradeⅠand Grade Ⅱ+Ⅲ meningiomas.Conclusion ADC map can be used to differentiate between tumors and edema, FA map can display the detailed relationship between tumors and nearby white matter tract, and it is useful to determine the plan before surgery. Combined with conventional MRI, DTI may be helpful in grading for meningiomas.