脑梗死期相演变中DTI参数变化的动态观察

目的:探讨各期相脑梗死DTI参数的变化规律。方法:70例脑梗死患者根据Osborn分类方法,分为超急性期(6例),急性期(8例),急性晚期(15例),亚急性早期(12例),亚急性晚期(15例)以及慢性期(14例)。对每例行常规MRI及DTI检查,在所生成平均扩散系数(average diffusion coefficient,DCavg)、部分各向异性(fractional anisotropy,FA)、容积比各向异性(volume ratio anisotropy,VRA)、各向同性(isotropy,Iso)、衰减指数(exponential attenuation,Exat)、T2加权迹线(T2-weighted Trace,T2-WT)等参数图像中测量病灶中心值,并取对称区域作为正常对照;观察病灶与正常对照的6项参数在脑梗死6期演变中的变化。结果:①超急性期脑梗死患者其DCavg明显低于对侧正常组织(P0.05),Iso、Exat及T2-WT均高于对侧正常组织(P0.05),FA及VRA和对侧比较差异无统计学意义(P0.05);急性期、急性晚期及亚急性早期病灶DCavg、FA及VRA均低于对侧正常组织(P0.05),Iso、Exat及T2-WT值均高于对侧(P0.05);亚急性晚期病灶DCavg值较对侧增高(P0.05),FA、VRA及Exat值则较对侧减低(P0.05),Iso及T2-WT值和对侧变化不大(P0.05);慢性期病灶DCavg明显增高(P0.05),FA、VRA、Iso、Exat及T2-WT值呈减低改变(P0.05)。②DCavg、Iso、Exat及T2-WT在脑梗死超急性期、急性期、急性晚期及亚急性早期中的变化不明显(P0.05),而其DCavg均明显低于慢性期(P0.05),Iso、Exat及T2-WT均明显高于慢性期(P0.05);FA及VRA于超急性期、急性晚期、慢性期逐渐变小(P0.05)。结论:通过DTI参数测量比较及诸功能图观察,不仅可以诊断脑梗死,还可以判断其期相。

Dynamic observation of the parameters of diffusion tensor imaging in the development of phases of cerebral infarction

Objective：To study the variation discipline of the 6 parameters of diffusion tensor imaging（DTI） in the development of 6 phases cerebral infarction. Methods： 70 cases with cerebral infarction were divided into 6 phases groups by Osborn Phasing, that included superacute phase（6）,acute phase（8）,later-acute phase（15）,early-subacute phase（12）,later-subacute phase（15）, and chronic phase（14）. All cases were checked by routine MR and DTI,the 6 DTI parameters of focus and its symmetrical area were measured in their 6 DTI parameter maps. The 6 parameters of focus and its symmetrical area,of 6 phases were contrasted respectively. Results：O In superacute phase, DCavg of focus was lower than of normal（P~ O. 05）,/so, Exat and T2 weighted Trace were higher （P~0. 05） ,FA and VRA of focus are similar with normal（P~〉0.05）. In acute,later-acute,and early-suba- cute phase, DCavg, FA and VRA of focus were lower than of normal（P~0.05）. Iso, Exat and T2-weighted Trace were higher （P〈0.05）. In late〉acute phase,DCavg of focus was higher than of normal（P~0. 055 ,FA ,VRA and gxat were lower（P-〈 0.05）. Iso and T2 weighted Trace of focus were similar with normal（P~0.05）. In chronic phase DCavg was higher （P〈 0.05 ）, FA, VRA, Iso, Exat and Tz-weighted Trace were lower （P〈 0.05 ）. （~） To infarction focus, DCavg, Iso, Exat and T2- weighted Trace were similar among the superacute, acute,later-acute, early-subacute phases（P~〉0.05）, and DCavg of the 4 pha- ses were lower than of chronic phase （P〈O. 05）. /so, Exat and T2-weighted Trace were higher than of chronic phase（P〈 0.05）. FA and VRA got lower gradually during the process of superacute, later-acute, and chronic phases（P〈0.05）. Conclu- sion：The 6 parameters of DTI can not only diagnose cerebral infarction but also can evaluate its phase and development stage.