Evaluation Of Multi-parameter Perfusion MRI In Predicting IDH Genotype Of Diffuse Glioma

Objective:To evaluate the value of three-dimensional arterial spin labeling(3D-ASL),dynamic contrast enhanced(DCE)and intravoxel incoherent motion(IVIM)perfusion magnetic resonance imaging(MRI)in predicting IDH gene phenotype in diffuse gliomas.Methods:A total of 65 patients with diffuse glioma confirmed by pathology after operation were included in the study.All patients had IDH phenotype results from immunohistochemistry or direct sequencing.All patients had underwent ASL and DCE sequences MRI examination,and only 50 patients had underwent IVIM examination.Among 65 patients,28 patients were IDH mutant and 37 patients were IDH wildtype.Measurement of kinetic parameters of ASL:ROIs were placed in the solid components of tumor and contralateral normal parenchymal matter to measure the values of cerebral blood flow(CBF).The relative CBF(rCBF)value was calculated by dividing the CBF of solid components of tumor by CBF of contralateral normal parenchymal matter.Measurement of kinetic parameters of DCE:ROIs were placed same as in ASL sequence.The relative volume transfer constant(Ktrans),extravascular-extracellular space volume fraction(Ve),plasma volume fraction(Vp)was calculated same as rCBF.Measurement of IVIM:ROIs were placed in the solid components of tumor on slow ADC and fast ADC map and the values of absolute D and D*was measured.The differences of 3D-ASL,DCE-MRI and IVIM parameters between IDH mutant group and IDH wild type group were compared using Mann-Whitney test.Receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficacy of the parameters with significant statistical differences.Results:The values of rCBF,rKtrans,rVe,rVP and D*in IDH mutant were significantly lower than that of IDH wildtype(P<0.05).The value of D in IDH mutant were significantly higher than that of IDH wildtype(P<0.05).The AUC of rCBF was 0.847,with the cut-off point of 1.56,and the specificity and sensitivity were 75.00%and 83.78%respectively.The AUC of rKtrans was 0.982,with the cut-off point of 4.38,and the specificity and sensitivity were 96.43%and 97.3%respectively.The AUC of rVe was 0.893,with the cut-off point of 10.91,and the specificity and sensitivity were 92.86%and 75.68%respectively.The AUC of rVp was 0.884,with the cut-off point of 3.25,and the specificity and sensitivity were 85.71%and 89.19%respectively.The AUC of D was 0.874,with the cut-off point of 0.83×10-3,and the specificity and sensitivity were 73.33%and 88.89%respectively.The AUC of D*was 0.770,with the cut-off point of 3.2×10-3,and the specificity and sensitivity were 60.00%and 88.89%respectively.Conclusion:The rCBF,rKtrans,rVe,rVp and D of the solid components of tumor all had good diagnostic efficacy in predicting IDH gene mutation in diffuse glioma.Among the above parameters,the relative rktrans had the best diagnostic efficacy in predicting IDH gene mutation in diffuse glioma.