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

Xiaoguang Li,Xiaoguang Li,Yongshan Zhu,Weiguo Zhang,Weiguo Zhang,Sumei Wang,Huaping Liang,Huaping Liang,Yulong Zhang,Yulong Zhang,Houyi Kang

doi:10.1186/s40644-015-0039-z

Abstract

BackgroundDynamic 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 (Ktrans) accuracy, the volume of extravascular extracellular space (EES) per unit volume of tissue (Ve) derived from DCE-MRI, and the degree of ITSS in glioma grading.MethodsThirty-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. Ktrans values, Ve, and the degree of ITSS in glioma were compared. Receiver operating characteristic (ROC) curve analysis determined diagnostic performances of Ktrans and Ve in glioma grading, and Spearman’s correlation analysis determined the associations between Ktrans, Ve, ITSS, and tumor grade.ResultsKtrans and Ve 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). Ktrans values were moderately correlated with ITSS in the same segments (P < 0.01).ConclusionKtrans and Ve 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 Ktrans and ITSS in the same tumor segments.

Highlights

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)
In the present study, it was inferred that a large number of angiogenesis with imperfect functions may reside within the ITSS regions and that ITSS grades may excellently correspond with the maximal Ktrans value, so these two parameters were both applied to diagnose glioma grades
The cut-off value of Ktrans (0.054 min−1) for differentiation between low grade gliomas (LGGs) and high grade gliomas (HGGs) provided the best combination of sensitivity (94.1%) and specificity (93.3%), and the area under the curve (AUC) of Ktrans was 0.941

Summary

Introduction

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). Researchers have found that parameters associated with DCE-MRI and the degree and distribution of ITSS are significantly correlated with the grades of gliomas [6,7,8,9,10]. These two methods can reveal the pathophysiological state of glioma microvessels from different angles. These two methods were applied to assess gliomas, to evaluate the accuracy and value of the associated parameters in diagnosing the grades of gliomas, and to analyze the correlation between the Ktrans value and ITSS in the same tumor section as well as the relations between these two parameters and microvessel density(MVD) and vessel diameter(VD)

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Discussion

Conclusion