Differentiation of fibroblastic meningiomas from other benign subtypes using diffusion tensor imaging

Abstract

Purpose: To differentiate fibroblastic meningiomas, usually considered to be of a hard consistency, from other benign subtypes using diffusion tensor imaging (DTI). Materials and Methods:From DTI data sets of 30 patients with benign meningiomas, we calculated diffusion tensors and mean diffusivity (MD) and fractional anisotropy (FA) maps as well as barycentric maps representing the geometrical shape of the tensors. The findings were compared to postoperative histology. The study was approved by the local ethics committee, and informed consent was given by the patients.Results: According to one-way analysis of variance (ANOVA), FA was the best parameter to differentiate between the subtypes (F ϭ 32.2; p Ͻ 0.0001). Regarding tensor shape, endothelial meningiomas were represented by spherical tensors (80%) corresponding to isotropic diffusion, whereas the fibroblastic meningiomas showed a high percentage (43%) of nonspherical tensors, indicating planar or longitudinal diffusion. The difference was highly significant (F ϭ 28.4; p Ͻ 0.0001) and may be due to the fascicular arrangement of long spindle-shaped tumor cells and the high content of intra-and interfascicular fibers as shown in the histology. In addition, a capsule-like rim of the in-plane diffusion surrounded most meningiomas irrespective of their histological type. Conclusion:If these results correlate to the intraoperative findings of meningioma consistency, DTI-based measurement of FA and analysis of the shape of the diffusion tensor is a promising method to differentiate between fibroblastic and other subtypes of benign meningiomas in order to get information about their "hard" or "soft" consistency prior to removal.

Diagnostic Utility of Diffusion Tensor Imaging in Differentiating Glioblastomas from Brain Metastases

“…26 These findings can be explained by the presence of a large amount of collagen in fibroblastic subtypes. 25,33 It has been reported that the structure and orientation of extracellular matrix affect the anisotropy, but not the mean diffusivity 34 ; these results are consistent with ours. On the other hand, in brain metastases, neoplasm cells grow into the brain parenchyma in an expansive, noninfiltrating pattern.…”

Assessment of Angiographic Vascularity of Meningiomas with Dynamic Susceptibility Contrast-Enhanced Perfusion-Weighted Imaging and Diffusion Tensor Imaging

“…Previous studies investigated the roles of ADC and FA in subtyping meningiomas, but the results were controversial. 7,8,27 In the present study, we found that angiographic vascularity of meningiomas correlated with FA but not with ADC. Whereas ADC measures the average changes of water diffusivity, FA quantifies the diffusion anisotropy.…”

Diffusion-Weighted MR Imaging: Diagnosing Atypical or Malignant Meningiomas and Detecting Tumor Dedifferentiation

“…Diffusion tensor imaging, involving 6 or more gradient directions, can also be used to provide information about the tumor consistency and to potentially study the benign and malignant subtypes of meningioma. 28,29 Two patients with benign meningiomas had recurrence of atypical/malignant tumors on follow-up imaging, which showed a change from isointensity to hyperintensity on DW MR imaging and a reduction in the ADC value and NADC ratio below the threshold for higher tumor grade. Although, as a group, the qualitative analysis of the signal intensity on DW MR images was variable and could not be used for distinguishing groups, in these 2 patients, tumor dedifferentiation could be detected visually on presurgical neuroimaging.…”