Background and purpose: The most common primary tumors of the central nervous system are gliomas. The gold standard choice to determine grade of glial tumor is biopsy which is an invasive method. Accurate assessment of tumor grade is important for determination of appropriate treatment strategies. The purpose of this study was to evaluate the role of Diffusion Tensor imaging (as a non-invasive method) by fractional anisotropy (FA) in glial tumor grading.

Materials and methods: A prospective study was performed in 20 patients with histologically confirmed gliomas. Patients underwent Diffusion Tensor Imaging by a 1.5-Tesla magnetic resonance scanner. In this study we defined two regions of interest (ROIs); white matter adjacent to the tumor and the homologous fiber tracts to first ROI in the contralateral hemisphere. The fractional anisotropy in these regions was calculated in SPSS and the relationship between FA and gliomas grade was determined.

Results: FA_t values and ratio of the low-grade gliomas tended to be higher than those of the high-grade gliomas in the peritumoral fibers (P-value FA_t=0.006 and_,P-value FA_t/n=0.02).

Conclusion: Our findings suggest that FA could be helpful in tumor grading.