Alzheimer's disease (AD) and mild cognitive impairment (MCI) are associated with progressive gray matter loss, particularly in medial temporal structures. In this study, CAT12/SPM12 voxel-based morphometry was applied to baseline T1-weighted MRI scans from 249 ADNI participants (CN = 90, MCI = 129, AD = 30). Gray matter volume was analyzed using a general linear model, with the diagnostic group as primary predictor and age and total intracranial volume as covariates. Statistical maps were thresholded at p < 0.001 (voxelwise) and corrected for multiple comparisons at the cluster level using family-wise error (FWE) correction (p < 0.05). Significant hippocampal atrophy was observed in AD relative to CN and MCI (Cohen's d = 2.03 and 1.61, respectively). Hippocampal volume demonstrated moderate predictive value for conversion from MCI to AD (AUC = 0.66). Stratification by APOE4 status did not reveal significant genetic effects on cross-sectional hippocampal volume. These results support medial temporal degeneration as a key feature of AD progression and provide insights into predictive biomarkers and genetic influences.

翻译：阿尔茨海默病（AD）与轻度认知障碍（MCI）均与进行性灰质丧失相关，尤其在颞叶内侧结构中。本研究对来自249名ADNI参与者（认知正常者=90，MCI=129，AD=30）的基线T1加权MRI扫描，应用CAT12/SPM12基于体素的形态学分析。采用一般线性模型分析灰质体积，以诊断组为主要预测因子，年龄和总颅内体积作为协变量。统计图设定体素水平阈值p < 0.001，并在团块水平采用家族性误差校正进行多重比较校正（p < 0.05）。结果显示，相较于认知正常组与MCI组，AD组存在显著海马萎缩（Cohen's d值分别为2.03与1.61）。海马体积对MCI向AD转化具有中等预测价值（AUC = 0.66）。按APOE4状态分层分析未发现遗传因素对横断面海马体积的显著影响。这些结果支持颞叶内侧退行性变是AD进展的关键特征，并为预测性生物标志物及遗传影响提供了新的见解。