Zeynep FIRAT, Cumhur Kaan YALTIRIK, Gazanfer EKINCI
Marmara Medical Journal - 2026;39(2):110-115
Objective: This study investigates the diagnostic potential of fractional anisotropy (FA), derived from diffusion tensor imaging (DTI), for distinguishing low-grade (grade 1-2) from high-grade (grade 3-4) gliomas by evaluating the tumor core, tumor margin, and peritumoral region. Patients and Methods: Sixty patients with histopathologically confirmed gliomas (grade 1-2, n=30; grade 3-4, n=30) underwent preoperative 3T Magnetic Resonance Imaging (MRI) including DTI. FA was measured in the tumor core (solid component), tumor margin, peritumoral region, and contralateral normal-appearing white matter (NAWM). NAWM-normalized FA ratios were also evaluated. Groups were compared using independent-samples t tests, and diagnostic performance was evaluated with receiver operating characteristic (ROC) analysis including AUC, optimal cut-off, sensitivity, and specificity. Results: Fractional anisotropy in tumor-related regions was lower than contralateral NAWM in both groups. Grade 3-4 gliomas showed significantly lower raw FA in the tumor core, tumor margin, and peritumoral region, whereas NAWM FA did not differ between groups. NAWM-normalized FA ratios were also significantly reduced in grade 3-4 gliomas (all p < 0.05). Tumor core raw FA showed the highest discrimination (AUC = 0.842, 95% CI: 0.734-0.932, cut-off = 0.150, sensitivity = 0.80, specificity = 0.73). Conclusion: Raw and NAWM-normalized FA metrics, particularly in the tumor core and peritumoral region, differentiated grade 1-2 from grade 3-4 gliomas and may serve as supportive noninvasive markers for preoperative grading.
