脑白质疏松弥散加权成像研究

目的 探讨脑白质疏松（LA）患者脑白质微结构的MRI变化及其与认知障碍的关系.方法 对55例LA患者和22名健康对照者行弥散加权成像（DWI）检查,测量LA病灶和正常白质区域的平均弥散系数（ADC）,并对所有入选者行神经心理测试（简易智能精神状态量表,MMSE）.结果 LA程度越严重,ADC值越高,从正常白质ADC值（0.69±0.04）×10^-3mm^2/s,到严重LA患者ADC值（1.10±0.05）×10^-3 mm^2/s,二者呈正相关.MMSE评分与LA患者的正常白质区域的ADC值明显相关,尤其是半卯圆中心的正常白质（P〈0.01）.结论 DWI检查中的ADC能够显示出LA的特征性改变,DWI能够发现常规MRI检查正常的脑白质微结构变化,且这种改变与认知功能相关.

Diffusion weighted imaging study of leukoaraiosis

Objective To find ADC values of regions of interest （ROI）correlating with the degree of the severity of leukoaraiosis（LA）by using diffusion weighted imaging （DWI）,and provides information about white matter microstructural changes and correlates with cognition dysfunction.Methods Diffusion weighted MR imaging was performed in 55 patients with LA（25 healthy subjects with LA and 30 ischemic with LA）,ILA（ischemic LA）lesions and normal white matter areas.Results The more severe the LA was,the higher the ADC values of the leukoaraiotic regions were,which was positive correlation.From the normal white matter ADC values of（0.69±0.04）×10^-3 mm^2/s,to severe leukoaraiosis in patients with ADC values of（1.10±0.05）×10^-3 mm^2/s.The significant correlation was identified between normal appearing white matter of DWI and MMSE scores,especially in the white matter of semi-oval（P〈0.01）.Conclusions The regions of LA are depicted characteristic changes in ADC values by DWI,DWI can find microstrutural white matter changes which are normally seen with conventional MRI,and these changes correlate with cognition dysfunction.