脑白质疏松症的磁共振扩散张量成像研究及其与急性腔隙性脑梗死的鉴别

目的 研究脑白质疏松症(LA)和急性腔隙性脑梗死(LD在磁共振扩散张量(DTI)影像学上的特点,探讨DTI对LA诊断及其与LI鉴别诊断的价值.方法 对28例LA患者、11例LI患者和20名正常老年人行DTI扫描,测量LA病灶区、形似正常(NAWM)区、LI梗死中心、健侧对应部位和对照组正常白质区的平均扩散系数(MD)、部分各项异性(FA)值.结果 LA患者病灶分别较NAWM、对照组以及LA NAWM区较对照组,MD值升高,FA值降低.各组大脑半球左右侧(除LA NAWM区侧脑室前端和后端周围MD值外)MD和FA值无显著性差异;随LA严重程度增加,MD值升高,而FA值降低;LI梗死中心较健侧对应部位和对照组MD值、FA值均较对照组降低.结论 DTI在监测脑白质病变上远比常规MRI灵敏度高,可发现早期的LA病变.LA的DTI参数变化反映了脑白质微结构改变.LA和急性LI在DTI的表现有特征性差异,显示出DTI在LA诊断及其与LI鉴别诊断的价值.

A DTI study of leukoaraiosis and its differential diagnosis from acute lacunar infarction

Objective To investigate the characteristics of leukoaraiosis (LA) and acute lacunar infarction (LI) on diffusion tensor MR imaging (DTI) and evaluate the differential diagnostic value of DTI between LA and acute LI. Methods Twenty-eight LA patients, 11 LI patients and 20healthy aged people were examined by DTI. The mean diffusion coefficient (MD) and fractional anisotropy (FA) values were measured in the lesions and normal appearing white matter (NAWM) of LA, the infarction focus and counterpart in the contralateral hemisphere of LI, and normal white matter of control group. Results The order of MD values was: MD (LA lesions)>MD (LA NAWM)>MD (control group), while the order of FA values was: FA (LA lesions)