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. K(trans) and V(e) 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.