Quantitative evaluation of intravoxel incoherent motion diffusion-weighted imaging in proliferation of brain gliomas

Objective To investigate the value of quantitative parameters derived from intravoxel incoherent motion diffusion weighted imaging (IVIM-DWI) in proliferation (Ki-67LI) of brain gliomas. Methods A retrospective analysis of 42 cases of gliomas confirmed by surgical pathology from December 2016 to June 2018 were performed. All patients underwent conventional magnetic resonance imaging (MRI) and IVIM-DWI before operation, then measured the true water diffusion coefficient (D),microcirculation perfusion coefficient (D*) and perfusion fraction (f) in the tumor solid area. Spearman' s correlation was used to analyze the correlation between the quantitative parameters and Ki-67LI. Those parameters and the Ki-67LI were compared between the low- and high- grade gliomas with Mann-Whitney U test. The ROC curve was used to assess the diagnostic efficacy of parameters in the grading assessment of gliomas. Results There was a moderate negative correlation between D, f and Ki-67LI(r=-0.514, -0.462, P<0.05). There was no significant correlation between D* and Ki-67LI (P=0.573). The D and f of the high-grade gliomas were lower than those of the low-grade gliomas， whereas D* and Ki-67LI were higher (P<0.05). The area under the curve (AUC) for identifying high- and low-grade gliomas by D, D* and f was 0.963, 0.745, and 0.841, respectively (P<0.05). Conclusion D and f can be used for quantitative prediction of proliferation. IVIM-DWI is helpful in the grading assessment of gliomas, and the diagnostic efficiency of D is the highest.