Evaluating the grade and IDH mutation status of gliomas by using intravoxel incoherent motion (IVIM) MRI and DSC perfusion MRI

BACKGROUND: This study aimed to evaluate the diagnostic performance of intravoxel incoherent motion (IVIM) imaging and DSC perfusion MRI to predict the IDH mutation status of gliomas and differentiate high-grade gliomas (HGG) from low-grade gliomas (LGG). METHODS: In this retrospective study, IVIM parameters, including perfusion fraction (f), tissue diffusion (D), and pseudodiffusion (D*), were obtained using a double exponential IVIM model in 61 patients with a pathological diagnosis of glioma. Imaging was performed on a 3 Tesla MRI scanner using only four b-values (0, 50, 400, and 800 s/mm²). The diagnostic performance of rCBV, f, D, D*, ADC, and age parameters in distinguishing HGG from LGG and predicting IDH mutation status in gliomas was evaluated using ROC curve analysis, and their diagnostic powers were compared using the DeLong test. RESULTS: rCBV, f, and age were higher in patients with HGG, whereas D and ADC were higher in patients with LGG (p < 0.001). rCBV showed the highest AUC for HGG-LGG differentiation (AUC = 0.983), without statistically significant superiority over f, D, or ADC by DeLong testing. rCBV, f, and age were higher in patients with IDH-wild type (IDH-WT) gliomas, whereas D and ADC values were higher in IDH-mutant type (IDH-MT) gliomas (p < 0.05). D showed the highest observed AUC for predicting IDH mutation status (AUC = 0.894) without statistically significant superiority over rCBV, f, or ADC by DeLong testing. CONCLUSIONS: IVIM D obtained from a simplified four-b-value protocol may provide complementary information for predicting IDH mutation status in gliomas. However, these preliminary findings require validation in larger, multicenter cohorts.