T1加权像动态对比增强MRI在评价脑胶质瘤微血管通透性及病理分级中的应用价值

目的: 探讨T1加权像动态对比增强MRI(DCE-MRI)中的容积转运参数(Ktrans)及血管外细胞外间隙容积比(Ve)在定量评估脑胶质瘤微血管通透性中的价值及其与肿瘤病理分级的相关性。方法: 经术后病理证实的26例脑胶质瘤患者中Ⅱ级12例,Ⅲ级8例,Ⅳ级6例。手术前均行DCE-MRI并在相应后处理软件获得Ktrans、Ve值。采用单因素方差分析比较不同级别胶质瘤Ktrans与Ve值的差异,应用相关分析探讨Ktrans、Ve值及胶质瘤级别三者两两之间的相关性。应用受试者工作特征曲线分析获得Ktrans、Ve值,鉴别不同级别胶质瘤的最佳阈值及其敏感性和特异性。结果: Ⅱ级胶质瘤的Ktrans及Ve值均显著低于Ⅲ级和Ⅳ级胶质瘤(P<0.01),但Ⅲ级与Ⅳ级差异无统计学意义(P>0.05)。当Ktrans和Ve值分别为0.054/min和0.296时可以鉴别出Ⅱ级与Ⅲ级胶质瘤;当Ktrans=0.084/min和Ve=0.345时可鉴别Ⅱ级与Ⅳ级胶质瘤。Ktrans和Ve值均与胶质瘤级别呈正相关关系(P<0.01),Ktrans值与Ve值也呈正相关关系(P<0.01)。结论: DCE-MRI通过评估肿瘤血管通透性不仅可以鉴别Ⅱ级与Ⅳ级胶质瘤,还可鉴别Ⅱ级与Ⅲ级胶质瘤,为临床提供了重要的辅助诊断参考价值。

Application of dynamic contrast enhanced MRI in evaluating the microvascular permeability and glioma grade

Objective: To explore the value of the volume transfer constant(Ktrans) and volume fraction of extravascular extracellular space(Ve) of dynamic contrast enhanced MRI(DCE-MRI) in evaluating the microvascular permeability of glioma,and correlation of the Ktrans and Ve values and pathological grade of tumor.Methods: The values of Ktrans and Ve of DCE-MRI in 26 patients with glioma(including grade Ⅱin 12 cases,grade Ⅲ in 8 cases and grade Ⅳ in 6 cases) diagnosed by pathology after operation were obtained before operation.The differences of the values of Ktrans and Ve in different grades gliom were compared using One-way AVOVA.Pearson correlation analyses were used to determine relationship between Ktrans,Ve,and glioma grade.Receiver operating characteristic curve analyses were performed to determine the threshold of Ktrans and Ve to distinguish different grades of gliomas.Results: The values of Ktrans and Ve in grade Ⅱ were significantly lower than those in grade Ⅲ or grade Ⅳ gliom(P<0.01),the differences of whose between grade Ⅲ and Ⅳ glioms were not statistically significant(P>0.05).The thresholds of Ktrans and Ve for 0.054/min & 0.296 and 0.084/min & 0.345 could distinguish grade Ⅱ from Ⅲ and Ⅱ from Ⅳ glioma,respectively.The values of Ktrans and Ve and glioma grade,and Ktrans and Ve were positive correlations(P<0.01).Conclusions: DCE-MRI can be used to distinguish grade Ⅱ from Ⅳ glioma and grade Ⅱ from Ⅲ glioma by testing the microvascular permeability of tumor,which can provide the important information for clinical diagnosis.