Predictive Value of T2-weighted Perfusion and T1-weighted Permeability MRI Parameters in Determining IDH Mutational Status and Grade of Gliomas.

Aim: To assess the performance metrics of perfusion and permeability magnetic resonance imaging (MRI) parameters with optimal cut-offs in differentiating isocitrate dehydrogenase (IDH) genotype and tumor grade in patients with grade 2-4 gliomas.

Material and methods: This retrospective study included 36 patients surgically diagnosed with grade 2-4 glioma (six grade 2, seven grade 3, and 23 grade 4) with known IDH genotypes (23 IDH wild-type, 13 IDH mutant) between November 2021 and August 2023. All patients underwent preoperative perfusion and permeability MRI examinations with a 3.0 Tesla scanner. Parameters were calculated on colored map images. Using the intraclass correlation coefficient, intra- and inter-observer agreement was assessed. Following multiple testing correction, the perfusion parameters with statistically significant differences were subjected to receiver operating characteristic (ROC) analysis.

Results: Five MRI parameters (rCBV and rCBF from perfusion; Ktrans, Ve, and Vp from permeability) showed a significant difference between groups in terms of IDH genotype (p < 0.001). In ROC analysis, the best parameters in differentiating IDH genotype included rCBV and Ktrans; rCBV with a cut-off of 5.58 achieved an area under the ROC curve (AUC), sensitivity, specificity, and accuracy of 0.883, 95.7%, 76.9%, and 88.8%, respectively. For Ktrans, with a cut-off of 0.0727 min-1, these values were 0.893, 100%, 69.2%, and 88.8%, respectively. In ROC analysis, these two parameters with rCBF and Ve also showed good performance in differentiating low- and high-grade gliomas with an AUC, sensitivity, and accuracy exceeding 0.940, 86%, and 88%, respectively.

Conclusion: Perfusion and permeability MRI may provide useful parameters in differentiating the IDH genotype and grade of gliomas.