Comparison Of Intravoxel Incoherent Motion Diffusion Weighted Imaging And Arterial Spin Labeling In Grading Glioms

Purpose To determine the utility of intravoxel incoherent motion(IVIM) imaging in grading gliomas and compare IVIM perfusion metrics with arterial spin labeling(ASL)-derived cerebral blood flow(CBF).Materials and Methods Fifty-two patients with pathologic confirmed gliomas underwent IVIM and ASL imaging at 3.0 T. IVIM perfusion-related diffusivity(D*), perfusion fraction(f), product of f and D*(f?D*), true diffusivity(D) and apparent diffusion coefficient(ADC) were obtained to distinguish glioma grades. The CBF derived from pseudo-continuous ASL within the solid tumor was compared and correlated with IVIM perfusion metrics for grading of gliomas. Values were also normalized to the contralateral normal-appearing white matter. Receiver-operating characteristic was performed to determine diagnostic efficiency. The reliability was estimated with intraclass coefficient, coefficient of variance and Bland-Altman plots.Results IVIM perfusion metrics and CBF were significantly higher in the high-grade than the low-grade gliomas(P<0.001), ADC and D were significantly lower in the high-grade than the low-grade gliomas(P<0.001). f?D* differed significantly between grades II through IV(P<0.05 for all). The other metrics showed significant difference between grade II and grade III(P<0.05 for all). Area under the curve was largest for f?D* in distinguishing high-grade from low-grade gliomas(AUC=0.979, P<0.001) and between grade II and grade III(AUC=0.957, P<0.001). f?D* showed good correlation with CBF(r=0.696, P<0.001) and improved diagnostic efficiency of CBF in grading gliomas. D was strongly correlated with ADC(r=0.959, P<0.001)。Conclusion IVIM-derived metrics are promising biomarkers in preoperative grading gliomas. IVIM imaging may be an additive method to ASL and ADC for evaluating tumor perfusion and diffusion.