磁共振弥散张量成像对临床早期脑梗死的诊断价值

Clinical application of diffusion tensor imaging in acute stroke

目的 观察磁共振弥散张量成像（DTI）在早期脑梗死患者相关指标的动态变化,以判断缺血半暗带治疗时间窗对早期脑梗死诊断及治疗的指导意义.方法 对入住我院的35例早期脑梗死患者行DTI检查,测量梗死灶不同病期部分各向异性系数（FA）、平均弥散系数（DCavg）、相对各向异性系数（RA）、1-容积比（1-VR）及表面弥散系数（ADC）;并在病灶的中心及周边各取直径为5 mm的区域定义为中心区与边缘区,测定病灶中心区与边缘区上述值的变化.结果 病侧DCavg值随脑梗死演变时间变化呈明显减低（0.398 ±0.014）、逐渐回升（0.426 ±0.071）、假正常化升高的趋势（0.448 ±0.042）;在超急性期FA（0.418 ±0.033）、RA（0.401 ±0.028）、1-VR（0.392 ±0.047）,明显升高,以后呈不可复性减低的趋势（0.352 ±0.056）、（0.348 ±0.039）、（0.359 ±0.011）,差异有统计学意义（P均＜0.05）;ADC值在超急性期（0.354 ±0.051）×10-3mm2/s与急性期（0.368 ±0.046）×10-3mm2/s明显减低,在亚急性期（0.388 ±0.022）×10-3mm2/s逐渐恢复到与健侧几乎同一水平.DCavg超急性期、急性期病灶中心区（0.403±0.056、0.419±0.022）与边缘区（0.431±0.031、0.458±0.013）比较差异有统计学意义（P=0.004,P=0.001）、ADC值超急性期病灶中心区[（0.316±0.054）×10-3 mm2/s与边缘区（0.371±0.040）×10-3mm2/s;急性期病灶中心区（0.327±0.036）×10-3mm2/s与边缘区（0.373±0.030）×10-3mm2/s]差异也有统计学意义（P=0.009,P=0.000）,急性期病灶中心区与边缘区的FA（0.451±0.026、0.502 ±0.029）差异也有统计学意义（P=0.000）.结论 梗死灶的FA、DCavg、RA、1-VR及ADC值具有特征性演变规律;可早期推断出缺血半暗带,为治疗争取时间.

Objective To reveal the transmiting discipline of parameters and define therapy time window of ischemia penumbra by continuous detection of diffusion tensor imaging（DTI） o Methods 35 patients with acute cerebral infarction in different phases were imaged with conventional DWI and DTI.To measure DCavg,FA,RA,1-VR,ADC in different regions of interest （ROI）.Results Change in DCavg had tendency which appear reduced obviously,elevated,renormalized,increased.FA/RA/1-VR of lesions elevated in hyperacute stroke and unrecovered declined acute to sub-acute stroke.Difference of DCavg,FA,RA,1-VR between central and periphral parts of lesions were significant in hyperacute and acute stroke.ADC of lesions were significant in hyperacute and acute stroke.Difference of FA between central and peripheral parts of lesions were significant in acute stroke（P ＜ 0.01）.Difference of ADC,DCavg between central and peripheral parts of lesions were significant in acute and subacute stroke（P ＜ 0.01）.Conclusion It had characteristic discipline in changes of DCavg,FA,RA,1-VR,ADC,The peripheral parts of lesions in hyperacute and acute stroke maybe ischemia penumbra,DTI has important practical value for clinical.