皮层下缺血性血管性痴呆胼胝体的扩散张量成像研究

目的：应用扩散张量成像（DTI）技术探讨皮层下缺血性血管性痴呆（SIVD）病人胼胝体各项异性及平均扩散率变化特点及其与认知状态或其他临床表现的关系。方法：对SIVD病人34例及同期进行体检的健康老年人26例进行DTI扫描，测量胼胝体前部和后部FA值、PA值及平均ADC值，并对结果进行统计分析。结果：健康对照组及SIVD组胼胝体后部FA及PA均大于前部（P〈0．05）；SIVD组胼胝体前后部FA及PA值均明显下降，ADC值均明显增加；胼胝体前部ADC与MMSE评分成负相关，r=-0．361，P=0，036。结论：应用DTI可显示SIVD病人胼胝体完整性破坏，髓鞘和轴索的损伤和丢失。胼胝体的DTI的各参数变化有助于SIVD的早期预防及治疗，阻止或逆转认知下降。

The corpus callosum in subcortical ischemic vascular dementia: a diffusion tensor imaging study

Objective:To investigate whether corpus callosum (CC) abnormalities are present and its characteristic in SIVD and the relationship between the DTI paremeters and cognitive status. Methods:The research was performed in 34 SIVD patients and 26 age-matched nondemented older adults. All patients and controls received DTI examination. For each individual, regional FA(fractional anisotropy), PA(principal anisotropy, FApri) and mean ADC measures were estimated in the splenium and genu of the CC. Results:FA and PA value in the posterior corpus was greater than genu in both control and groups. In SIVD group, FA, PA significantly decreased, and mean ADC significantly increased. Negative correlation was found between MMSE and mean ADC values of genu of corpus callosum (r=-0.361, P=0.036). Conclusions:This finding hints that DTI can find the white matter integrity destruction, demyelination and axon loss of corpus callosum, which may be potential morphological substrates of cognitive dysfunction. DTI appears to be a promising technique for white matter damage differences in SIVD. These results may be helpful for early and accurate prevention and treatment of SIVD, and for preventing or reversing cognitive decline.