中文摘要：

目的：通过动态对比增强磁共振成像（DCE-MRI）获得脑胶质瘤的容积转运参数（Ktrans）与血管外细胞外间隙容积比（Ve），探讨它们定量评估脑胶质瘤微血管通透性的价值。方法：研究对象包括71例脑胶质瘤患者，其中Ⅱ级31例，Ⅲ级8例，Ⅳ级32例。每名患者经过DCE-MRI成像获得胶质瘤的Ktrans与Ve的最大值。应用Mann—WhitneyU检验比较不同级别胶质瘤Ktrans值与Ve值的差异，应用SpearmanSH关系数分析Ktrans值、Ve值与胶质瘤分级的相关性，应用ROC曲线分析Ktrans值、Ve值鉴别不同级别胶质瘤的最佳切峰值及敏感性与特异性。结果：除了Ⅲ级与Ⅳ级胶质瘤Ktrans值与Ve值差异无统计学意义之外，其余各级别胶质瘤Ktrans值与Ve值的差异均有统计学意义（P〈O．01）。Ktrans值、ve值均与胶质瘤分级正相关（P〈0．001）。ROC曲线分析显示，Ktrans与ve的最佳切峰值为鉴别Ⅱ级与Ⅲ级、Ⅱ级与Ⅳ级、低级别胶质瘤（LGG）与高级别胶质瘤（HGG）提供了较高的敏感性与特异性。结论：应用DCE—MRI可以为评估脑胶质瘤微血管的通透性提供重要参考价值。

英文摘要：

Purpose： To quantitatively assess the microvascular permeability of brain glioma with the volume transfer constant （Ktrans） and volume of extravascular extracellular space per unit volume of tissue （Ve） from dynamic contrast-enhanced magnetic resonance imaging （DCE-MRI）. Methods： The maximal values of Kt and Ve from 71 patients with gliomas （31 with grade II, 8 with grade III and 32 with grade IV）were obtained. Comparison of the differences of Kt and Ve values between the different grades was conducted using the Mann-Whitney rank-sum test. Spearman＇ s rank correlation coefficients were determined between Kt values, Ve values and glioma grades. Receiver operating characteristic （ROC） curve analyses were performed to determine the cut-off values for Kt and Ve to distinguish different grades of gliomas. Results： There were significant differences between the different grades for K＇ values and Ve values （P〈0.01） except grade III and IV. Kt values and Ve values were both correlated with glioma grades （P〈0.001）. The cut-off value of Kt and Ve provided the best combination of sensitivity and specificity in differentiation between grade II and III,.grade III and IV, LGG and HGG. Conclusion： Our results suggest that Kt and Ve from DCE-MRI have a high performance in assessing the microvascular permeability of brain glioma.