中文摘要：

目的通过基于解剖图谱的分析（ABA）方法，定量分析阿尔茨海默病（AD）、轻度认知障碍（MCI）患者脑深部灰质和白质结构的各向异性分数（FA）值，并探讨其与认知功能改变的关系。方法按诊断标准纳入AD患者21例（AD组）、MCI患者8例（McI组）和健康志愿者15名（对照组），均行常规MRI和扩散张量成像（DTI）。DTI原始数据通过ABA方法进行后处理，最终获得58个脑深部灰质和白质结构的FA值。3组之间FA值的差异采用单因素方差分析，随后两两比较。在AD组和MCI组内，消除年龄和教育年限的影响之后，将AD组与MCI组间以及MCI组与对照组间FA值差异有统计学意义脑区的FA值与简易精神状态量表（MMSE）评分进行偏相关分析。结果同对照组相比，AD组32个脑区结构，包括海马、丘脑和下丘脑深部灰质结构，以及扣带束、穹隆、胼胝体、放射冠、下纵束、上纵束、额顶束等深部白质结构FA值广泛降低（校正P值均〈0．05）。AD组下丘脑、穹隆、上纵束、扣带束等8个脑区结构的FA值明显低于MCI组（F值为4．738～11．132，校正P值均〈0．05）；MCI组右侧胼胝体压部的FA值（0．550±0．018）显著低于对照组（0．585±0．0261，差异具有统计学意义（P〈0．05）。在AD组和MCI组内，左侧下丘脑、右侧下丘脑、左侧扣带束、右侧扣带束及左侧上纵束的FA值与MMSE评分呈正相关（r值分别为0．502、0．515、0．535、0．527、0．512，P值均〈0．05），右侧胼胝体压部、右侧上纵束、右侧穹隆终纹部及右侧穹隆的FA值与MMSE评分无相关性（P值均〉0．05）。结论ABA显示AD患者不仅在脑白质而且在脑深部灰质均存在扩散特征的异常改变，而MCI患者仅胼胝体压部白质区域的扩散特征存在异常。胼胝体压部FA值的降低在疾病过程中较早发生，但与认知功能的下降相关性不大。下丘脑、扣带束、?

英文摘要：

Objective To identify the diffusion alterations of deep gray matter（GM） and white matter 0VM） among Alzheimer＇s disease （AD）, mild cognitive impairment （MCI） and healthy people by atlas- based analysis （ABA）, and to investigate the respective relationship with cognitive function. Methods Twenty-one AD patients （AD group）, 8 MCI patients （MCI group） and 15 normal controls （control group） were performed by conventional MRI and diffusion tensor imaging （DTI）. The raw data of DTI was processed by using DTI studio software to generate the fractional anisotropy （FA） images. Then ABA was used to quantify the FA value in 58 deep GM and WM structures. The differences of FA value among three groups were compared by using one way ANOVA, with a post-hoc analysis. In AD and MCI groups, the partial correlation was further investigated between mini-mental state examination （MMSE） score and FA value in the brain regions that have significant differences between AD and MCI group or between MCI and control group. Results Compared with control group, AD patients showed wide-spread FA decrease in most deep GM and WM regions （corrected P〈0.05）. The FA values of the hypothalamus, the fornix, the superior longitudinal fasciculus （SLF） and the cingulum in AD group were significantly lower than those in MCI group （corrected P〈0.05）. The FA value of the right splenium of corpus callosum （SCC） in MCI group was significantly lower than that in control group （MCI： 0.550±0.018 vs. Control： 0.585±0.026, P〈O.05）. In AD and MCI group, the FA values of the left hypothalamus, the right hypothalamus, the left cingulum, the right cingulum, and the left SLF were positively correlated with MMSE scores （r=0.502, 0.515, 0.535, 0.527, 0.512; P〈0.05）. No significant correlation was found between the FA value of the right SCC, the right SLF, the right fornix/stria terminalis, the right fornix and MMSE scores （P〉0.05）. Conclusion Based on ABA, this study found the diffus