中文摘要：

目的考察轻度认知损害（mild cognitive impairment，MCI）和阿尔茨海默病（Alzheimer’s disease，AD）的大脑灰质体积是否存在异常及其与记忆功能的关系。方法本研究共纳入56例轻度AD、14例MCI和16例正常对照，所有被试均进行了记忆功能测查和磁共振影像检查。影像数据分析采用患者基于体素的脑形态学分析（voxel—based morphometry，VBM）。结果AD组和MCI组记忆测验评分下降，呈AD组〈MCI组〈对照组趋势。AD组双侧颞叶、额叶及顶叶大脑灰质明显萎缩，其中额叶及顶叶萎缩比MCI组严重（P〈0．05）。在AD组中,瞬时物品回忆分数与颞叶、额叶及顶叶等广泛皮层区域存在关联。30min物品延迟回忆分数与双侧额上回、丘脑，右侧前扣带回、额内侧回、颞中回、中央旁回灰质体积显著相关（均P〈0．01）。复合记忆分数与左侧海马旁回、颞中回、楔前叶、额上回、额中回、扣带回以及右侧海马旁回、额内侧回以及额下回的灰质体积密切相关（均P〈0．01）。而在MCI与正常对照组中．未发现灰质体积与记忆测验评分显著相关的脑区。结论AD患者存在广泛的大脑灰质萎缩，AD患者的记忆损害与其密切相关。MCI的大脑体积与记忆能力间无显著相关，提示记忆损害尽管是MCI的早期信号，但并不直接归因于脑萎缩，尚需进一步开展微观结构或功能连接的研究。

英文摘要：

Objective To explore the relationship between the gray matter loss measured with voxel-based morphometry （VBM） and memory performance in mild cognitive impairment （MCI） and Alzheimer＇s disease （AD）. Methods Eighty-six subjects were recruited, including 56 patients with mild AD, 14 subjects with MCI, and 16 healthy controls. All subjects were administered the comprehensive memory tests, All 3D T1 images were analyzed by using the procedures of optimized VBM analysis. Results Compared to control group, memory performance were significantly worse in AD and MCI groups, in a pattern of AD 〈 MCI 〈 control. Gray matter loss was detected exten- sively in the temporal, frontal and parietal lobes in AD group. There was More severe atrophy in frontal and parietal lobes in AD compared to MCI group. In AD group, the 3D statistical maps showed extensive cortical areas in the temporal, frontal and parietal lobes were linked to immediate object memory performance. Score of 30-min delayed recall of objects was correlated strongly with the gray matter density in the bilateral superior frontal gyri, thalamus,right anterior cingulate, medial frontal gyri, middle temporal gyri, and paracentral lobule （P 〈 0.01 ）. Composite memory score was closely correlated with the gray matter density in the left parahippocampal gyrus, middle temporal gyri, precuneus, superior frontal gyri, middle frontal gyri, cingulate gyrus, and right parahippocampal gyrus, medial frontal gyri, and inferior frontal gyri （P 〈 0.01 ）. In MCI and NC groups, suprathreshold clusters were not correlated with the memory scores. Conclusion Memory impairment is strongly correlated with extensive cerebral atrophy in AD. Brain volume in MCI individuals are not significantly correlated with memory performance, suggesting that memo- ry impairment, an early sign of MCI, may not be directly attributable to brain atrophy. Further investigations on mi-crostructural or functional connectivity are warranted.