动态对比增强磁共振在鉴别脑胶质瘤真性进展和假性进展的研究

目的 探讨3.0 T动态对比增强磁共振(DCE-MRI)渗透性参数鉴别脑胶质瘤真性进展(TP)和假性进展(PP)的价值。 方法 回顾性分析32例脑胶质瘤术后放化疗后患者的DCE-MRI资料，并测量异常强化区渗透性参数的最大值，即转运常数(Ktrans)、细胞外血管外间隙的体积百分数(v_e)、回流常数(k_ep)和血浆体积百分数(v_p)。采用分组Mann-Whitney U检验比较脑胶质瘤TP和PP组间各参数，采用ROC曲线分析各参数的阈值、敏感性、特异性和曲线下面积(AUC)。 结果 32例患者中TP组(n=18)的Ktrans和v_e的中位值分别为0.34 min-1和0.53，明显高于PP组(n=14)的0.17 min-1和0.39，2组间差异均有统计学意义(Z=3.02,P＜0.01;Z=2.03,P＜0.05)，而k_ep值、v_p值组间差异无统计学意义(P＞0.05)。ROC曲线分析显示Ktrans值鉴别诊断脑胶质瘤真性进展的曲线下面积最大(0.815)，敏感性和特异性分别为72.2%和85.7%。 结论 磁共振动态对比增强渗透性参数有助于鉴别脑胶质瘤真性进展和假性进展的诊断，对临床进一步治疗有指导意义。 

Role of dynamic contrast-enhanced MRI in distinguishing pseudoprogression from true progression of glioma

Objective To evaluate the value of 3-T dynamic contrast-enhanced MRI(DCE-MRI)in distinguishing pseudoprogression(PP)from true progression(TP)of glioma. Methods DCE-MRI examination were performed in 32 cases of glioma to distinguish pseudoprogression fromtrue progression.The values of volume transfer constant(Ktrans),volume fraction of extravascular extracellular space(v_e),reflux constant(k_ep)and fractional plasma volume(v_p)were calculated in the newly developed abnormal enhancement by pharmacokinetic model.Mann-Whitney U test was used to calculate the statistical significance between TP group and PP group.Receiver operating characteristic(ROC)curve was performed for evaluation of the sensitivity,specificity and AUC. Results TP group(n=18)showed higher Ktrans(0.34 min-1 vs. 0.17 min-1)and higher v_e(0.53 vs. 0.39) when compared with the PP group(n=14),the differences were statistically significant(Z=3.02,P＜0.01;Z=2.03,P＜0.05).However,the differences in kep and ve were not statistically significant(P＞0.05).ROC curve showed the AUC value to diagnose TP and PP of Ktrans was the highest(0.815),and the sensitivity and specificity were 72.2% and 85.7%. Conclusion The permeability parameters on DCE-MRI is useful in distinguishing pseudoprogression from glioma true progression,and to be a guidance for clinical treatment.