皮质下缺血性血管性痴呆患者脑白质损害的磁共振弥散张量成像研究

The value of diffusion tensor imaging in evaluating the changes of microstructural integrity of white matter in subcortical ischemic vascular dementia patients

目的:应用磁共振弥散张量成像技术(DTI)观察皮质下缺血性血管性痴呆(SIVD)患者脑白质损害程度,探讨DTI对SIVD白质损害的评估及与阿尔茨海默病(AD)鉴别诊断价值。方法:研究对象分为3组,分别是健康老年人(NC)、皮质下缺血性血管性痴呆(SIVD)患者、AD患者,每组各20例。行常规MR I和DTI扫描后,测定相同感兴趣区(RO I)的各向异性分数(FA)值和表观扩散系数(ADC)值进行比较。结果:SIVD组下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位FA值下降,ADC值升高,与NC、AD组比较差异有统计学意义(P<0.05)。与NC组比较,AD组前额叶、颞叶、海马、下额枕束、胼胝体膝部和扣带束等部位FA值降低,颞叶、海马等部位ADC值升高,两组差异具有显著性(P<0.05);结论:DTI可以用来评估痴呆患者白质损害的程度,SIVD患者以下额枕束、胼胝体膝部、胼胝体压部、上纵束等部位受累为主,可作为与AD鉴别的客观指标。

Objective： To evaluate the diagnostic and differential diagnosis value of microstructural integrity of white matter（WM） changes in patients with subcortical ischemic vascular dementia（SIVD） using diffusion tensor imaging（DTI）. Method：Three groups were identified to normal control（NC） group,Alzheimer＇s disease（AD） group and SIVD group for 20 cases each.After routine MRI and DTI were completed,FA and ADC values were measured and compared on regions of interest（ROI）. Results：Compared to NC and AD group,there were significantly lower FA values and higher ADC values of inferior-frontooccipital fascicles,genu of corpuscallsum,splenium of corpuscallosum and superior longitudinal fasciculus in SIVD group（P0.05）.Compared to NC group,lower FA values of anterior frontal lobe,temporal lobe,hippocampus,inferior fronto-occipital fascicles,genu of corpuscallsum and cingulate fasciculus（P0.05）,higher ADC values of temporal lobe and hippocampus were found in AD group（P0.05）; Conclusion：DTI can be used to estimate the level of white matter（WM） impairment in dementia patients.There are significant regional reductions of FA values and higher ADC values in participants with SIVD group compared to AD group in multiple regions.It may be helpful in providing a more objective way of differential diagnosis between SIVD and AD.