Simplified Perfusion Fraction from Diffusion-Weighted Imaging in Preoperative Prediction of IDH1 Mutation in WHO Grade II–III Gliomas: Comparison with Dynamic Contrast-Enhanced and Intravoxel Incoherent Motion MRI
SPF, DCE and IVIM for IDH1 mutation
Effect of isocitrate dehydrogenase 1 (IDH1) mutation in neovascularization might be linked with tissue perfusion in gliomas. At present, the need of injection of contrast agent and the increasing scanning time limit the application of perfusion techniques. We used a simplified intravoxel incoherent motion (IVIM)-derived perfusion fraction (SPF) calculated from diffusion-weighted imaging (DWI) using only three b-values to quantitatively assess IDH1-linked tissue perfusion changes in WHO grade II-III gliomas (LGGs). Additionally, by comparing accuracy with dynamic contrast-enhanced (DCE) and full IVIM MRI, we tried to find the optimal imaging markers to predict IDH1 mutation status.
Thirty patients were prospectively examined using DCE and multi-b-value DWI. All parameters were compared between the IDH1 mutant and wild-type LGGs using the Mann–Whitney U test, including the DCE MRI-derived Ktrans, ve and vp, the conventional apparent diffusion coefficient (ADC0,1000), IVIM-derived perfusion fraction (f), diffusion coefficient (D) and pseudo-diffusion coefficient (D*), SPF. We evaluated the diagnostic performance by receiver operating characteristic (ROC) analysis.
Significant differences were detected between WHO grade II-III gliomas for all perfusion and diffusion parameters (P < 0.05). When compared to IDH1 mutant LGGs, IDH1 wild-type LGGs exhibited significantly higher perfusion metrics (P < 0.05) and lower diffusion metrics (P < 0.05). Among all parameters, SPF showed a higher diagnostic performance (area under the curve 0.861), with 94.4% sensitivity and 75% specificity.
DWI, DCE and IVIM MRI may noninvasively help discriminate IDH1 mutation statuses in LGGs. Specifically, simplified DWI-derived SPF showed a superior diagnostic performance.
Keywords: IDH1 mutation, glioma perfusion, diffusion-weighted MRI, dynamic contrast-enhanced MRI, intravoxel incoherent motion, 2016 WHO CNS tumor classification