磁共振T1、T2值在脑胶质瘤分级及细胞增殖活性预测中的临床价值

目的探讨磁共振平扫T1、T2值及增强后的T1值在脑胶质瘤分级及细胞增殖活性预测中的诊断价值。材料与方法回顾性分析手术病理证实的36例脑胶质瘤患者,其中高级别胶质瘤(high grade glioma,HGG)21例,低级别胶质瘤(low grade glioma,LGG)15例。所有患者在术前1周同时行多对比度一站式弛豫定量技术(magnetic resonance imaging compilation,Magic)扫描、Magic对比增强扫描。在增强前后生成的T1 mapping、T2 mapping测量肿瘤实质区、对侧镜像部位正常脑白质的增强前T1值(T1-pre)、T2值(T2-pre)及增强后T1值(T1-Gd)。对手术标本进行病理分级及Ki-67标记指数(Ki-67 LI)的测定。分析各项Magic参数及Ki-67 LI之间的相关性及高低级别组间Magic参数值、Ki-67 LI之间的差别,并绘制ROC曲线。结果T1-pre、增强前T1比值(ratio of T1-pre,rT1-pre)、T1-Gd、增强前后T1差值(ΔT1)、T1值变化百分比均与Ki-67 LI具有显著相关性(P<0.05),相关系数r分别为0.502、0.331、-0.351、0.537、0.473。高级别组胶质瘤T1-pre、ΔT1、T1值变化百分比、Ki-67 LI明显高于低级别组,T1-Gd、增强后T1比值(ratio of T1-Gd,rT1-Gd)低于低级别组,差异均具有统计学意义(P<0.05)。ΔT1对区分高、低级别胶质瘤的效能最好,其最佳诊断阈值373.25 ms,曲线下面积0.816,敏感度90.5%,特异度60%,P=0.001。结论定量测量T1值可用于鉴别高低级别胶质瘤,对预测肿瘤细胞增殖有一定的临床价值。

The clinical value of T1 and T2 values in predicting brain glioma grading and cell proliferation activity

Objective:To investigate the diagnostic value of T1,T2 and enhanced T1 value in predicting glioma grading and cell proliferation activity.Materials and Methods:Thirty-six patients with glioma confirmed by surgery and pathology were retrospectively analyzed,including 21 patients with high grade glioma(HGG)and 15 patients with low grade glioma(LGG).All patients underwent Magic scan and Magic contrast-enhanced scan one week before surgery.T1 mapping and T2 mapping were generated before and after enhancement.T1 value before enhancement(T1-pre),T2 value before enhancement(T2-pre)and T1 value after enhancement(T1-Gd)were measured in the solid portion of the tumor and normal white matter in the contralateral mirror.The pathological grades and Ki-67 labeling index(Ki-67 LI)of the surgical specimens were measured.The correlation between Magic parameters and Ki-67 LI and the difference between HGG and LGG of Magic parameters and Ki-67 LI were analyzed,and the ROC curve was drawn.Result:T1-pre,T1 ratio before enhancement(ratio of T1-pre,rT1-pre),T1-Gd,T1 difference before and after enhancement(ΔT1),T1 value percentage change was significantly associated with Ki-67 LI(P<0.05).The correlation coefficients r were 0.502,0.331,-0.351,0.537 and 0.473,respectively.T1-pre,ΔT1、T1 value percentage change,Ki-67 LI in HGG was significantly higher than LGG and T1-Gd,ratio of T1-Gd after enhancement(rT1-Gd)in HGG was lower than LGG.The differences were statistically significant(P<0.05).The diagnosis efficiency forΔT1 to distinguish HGG and LGG was best,the diagnostic threshold was 373.25 ms,area under the curve was 0.816,the sensitivity was 90.5%,and the specificity was 60%,P=0.001.Conclusions:Quantitative measurement of T1 value can be used to distinguish high grade glioma from low grade glioma,which has clinical value in predicting tumor cell proliferation.