Anisotropy Article Consistency Diffusion MRI Diffusion Magnetic Resonance Imaging Diffusion Tensor Imaging Humans Meningeal Neoplasms Meningioma Tensor-valued diffusion encoding Tumor grade Type adult aged anisotropy apparent diffusion coefficient area under the curve brain tissue cancer surgery clinical article comparative study controlled study diagnostic imaging diffusion tensor imaging diffusion weighted imaging distribution parameters female fractional anisotropy histogram histopathology