磁共振多技术在短暂性脑缺血发作中的临床应用价值

Value of different MR techniques in clinical diagnosis of transient ischemic attack

目的探讨磁共振弥散加权成像(DWI)、三维时间飞跃法血管成像(3D-TOF MRA)和三维动脉自旋标记(3D-ASL)灌注成像在短暂性脑缺血发作(TIA)中的诊断价值。方法选择临床诊断为TIA的患者53例为病例组,同期另选30例年龄匹配的健康志愿者作为对照组,入选者均行MRI常规扫描(T_1WI、T_2WI、T2-FLAIR)、DWI、3D-TOF MRA和3D-ASL扫描。根据扫描结果进行统计分析。结果 83例入选者DWI序列均未见高信号显示,3D-TOF MRA、3D-ASL及两者联合诊断TIA准确性分别为63.4%、71.1%、88.0%;敏感性分别为49.1%、58.5%、83.0%;特异性分别为90.0%、93.3%、96.7%。3D-TOF MRA与3D-ASL联合检查准确率、敏感性及特异性均明显高于两者单独检查(P<0.05)。病例组中,3D-TOF MRA阳性+ASL阳性的患者13例(24.5%);3D-TOF MRA阳性+3D-ASL阴性患者13例(24.5%);MRA阴性+ASL阳性的患者18例(34.0%);3D-TOF MRA阴性+3D-ASL阴性的患者9例(17.0%)。结论 3D-ASL、3D-TOF MRA和DWI检查方法各具优缺点,可从不同方面反映脑的特征,将三者联合应用可更好确诊TIA,追踪病情改变,应该作为TIA诊断的常规扫描序列。

Objective To study the value of DWI,3D-TOF MRA and 3D-ASL in diagnosis of transient ischemic attack （TIA）. Methods Fifty-three TIA patients served as a patient group and 30 age-matched healthy volunteers served as a control group in this study. They underwent T1WI, T2WI,T2-FLAIR,DWI,MRA and 3D-ASL. The findings in T1WI,T2WI,T2-FLAIR,DWI,MRA and 3D-ASL were statistically analyzed. Results DWI showed no high signals in the 83 subjects included in this study. The accuracy of MRA,ASL and their combination in diagnosis of TIA was 63.4%,71.1% and 88.0% respectively,with a sensitivity of 49.1%,58.5% and 83.0% respectively,and a specificity of 90.0%, 93.3% and 96.7% respectively. The accuracy, sensitivity and specificity of combined 3D-TOF MRA and 3D-ASL were higher than those of either 3D-TOF MRA or 3D-ASL （P〈0.05）. Of the 53 patients,24.5% were positive for both 3D-TOF MRA and 3D-ASL, 24.5% were positive for 3D-TOF MRA and negative for 3D-ASL,34.00% were negative for MRA and positive for 3D-ASL, 17.0% were negative for both 3D-TOF MRA and 3D-ASL. Conclusion 3D-ASL,3D-TOF MRA and DWI have their advantages and disadvantages,and can show the different characteristics of brain. Their combination can improve the diagnosis of TIA, follow the trail of changing condition,and can thus be used in diagnosis of TIA.