Glioma grading by microvascular permeability parameters derived from dynamic contrast-enhanced MRI and intratumoral susceptibility signal on susceptibility weighted imaging

Background: Dynamic contrast-enhanced MRI (DCE-MRI) estimates vascular permeability of brain tumors, and susceptibility-weighted imaging (SWI) may demonstrate tumor vascularity by intratumoral susceptibility signals (ITSS). This study assessed volume transfer constant (K-trans) accuracy, the volume of extravascular extracellular space (EES) per unit volume of tissue (V-e) derived from DCE-MRI, and the degree of ITSS in glioma grading. Methods: Thirty-two patients with different glioma grades were enrolled in this retrospective study. Patients underwent DCE-MRI and non-contrast enhanced SWI by three-tesla scanning. K-trans values, V-e, and the degree of ITSS in glioma were compared. Receiver operating characteristic (ROC) curve analysis determined diagnostic performances of K-trans and V-e in glioma grading, and Spearman's correlation analysis determined the associations between K-trans, V-e, ITSS, and tumor grade. Results: K-trans and V-e values were significantly different between low grade gliomas (LGGs) and both high grade gliomas (HGGs) and grade II, III and IV gliomas (P < 0.01). The degree of ITSS of LGGs was lower than HGGs (P < 0.01), and the ITSS of grade II gliomas was lower than grade III or IV gliomas. Ktrans and Ve were correlated with glioma grade (P < 0.01), while ITSS was moderately correlated (P < 0.01). K-trans values were moderately correlated with ITSS in the same segments (P < 0.01). Conclusion: K-trans and V-e values, and ITSS helped distinguish the differences between LGGs and HGGs and between grade II, III and IV gliomas. There was a moderate correlation between K-trans and ITSS in the same tumor segments.