Center for Imaging of Neurodegenerative Diseases, Department of Veterans Affairs Medical Center, San Francisco, California 94121, USA.
Hum Brain Mapp. 2010 Sep;31(9):1339-47. doi: 10.1002/hbm.20934.
Histopathological studies and animal models suggest that hippocampal subfields may be differently affected by aging, Alzheimer's disease (AD), and other diseases. High-resolution images at 4 Tesla depict details of the internal structure of the hippocampus allowing for in vivo volumetry of different subfields. The aims of this study were as follows: (1) to determine patterns of volume loss in hippocampal subfields in normal aging, AD, and amnestic mild cognitive impairment (MCI). (2) To determine if measurements of hippocampal subfields provide advantages over total hippocampal volume for differentiation between groups.
Ninety-one subjects (53 controls (mean age: 69.3 ± 7.3), 20 MCI (mean age: 73.6 ± 7.1), and 18 AD (mean age: 69.1 ± 9.5) were studied with a high-resolution T2 weighted imaging sequence aimed at the hippocampus. Entorhinal cortex (ERC), subiculum, CA1, CA1-CA2 transition zone (CA1-2), CA3 & dentate gyrus (CA3&DG) were manually marked in the anterior third of the hippocampal body. Hippocampal volume was obtained from the Freesurfer and manually edited.
Compared to controls, AD had smaller volumes of ERC, subiculum, CA1, CA1-2, and total hippocampal volumes. MCI had smaller CA1-2 volumes. Discriminant analysis and power analysis showed that CA1-2 was superior to total hippocampal volume for distinction between controls and MCI.
The patterns of subfield atrophy in AD and MCI were consistent with patterns of neuronal cell loss/reduced synaptic density described by histopathology. These preliminary findings suggest that hippocampal subfield volumetry might be a better measure for diagnosis of early AD and for detection of other disease effects than measurement of total hippocampus.
组织病理学研究和动物模型表明，海马亚区可能受到衰老、阿尔茨海默病（AD）和其他疾病的不同影响。4T 高分辨率图像可以描绘出海马内部结构的细节，从而实现不同亚区的活体容积测量。本研究的目的如下：（1）确定正常衰老、AD 和遗忘型轻度认知障碍（MCI）中海马亚区的体积损失模式。（2）确定海马亚区的测量值是否比总海马体积更有助于区分不同组。
91 名受试者（53 名对照组（平均年龄：69.3 ± 7.3），20 名 MCI（平均年龄：73.6 ± 7.1）和 18 名 AD（平均年龄：69.1 ± 9.5）接受了高分辨率 T2 加权成像序列的研究，该序列针对海马体。在海马体前部三分之一处手动标记内嗅皮层（ERC）、下托、CA1、CA1-CA2 过渡区（CA1-2）、CA3 和齿状回（CA3&DG）。使用 Freesurfer 获得海马体体积并进行手动编辑。
与对照组相比，AD 的 ERC、下托、CA1、CA1-2 和总海马体体积较小。MCI 的 CA1-2 体积较小。判别分析和功效分析表明，CA1-2 比总海马体体积更能区分对照组和 MCI。
AD 和 MCI 中海马亚区萎缩的模式与组织病理学描述的神经元细胞丢失/减少突触密度的模式一致。这些初步发现表明，与测量总海马体相比，海马亚区容积测量可能是诊断早期 AD 和检测其他疾病影响的更好方法。
