Combined Volumetry and DTI in Subcortical Structures of Mild Cognitive Impairment and Alzheimer's Disease Patients
Combined Volumetry and DTI in Subcortical Structures of Mild Cognitive Impairment and Alzheimer's Disease Patients
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DOI：
10.3233/jad-2010-091186
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发表时间：
2010-01-01
影响因子：
4
通讯作者：
Spalletta, Gianfranco
中科院分区：
文献类型：
--
作者：
Cherubini, Andrea;Peran, Patrice;Spalletta, Gianfranco
这项工作的目的是调查的假设，即多模态MRI能够检测遗忘型轻度认知功能障碍（a-MCI）和轻度阿尔茨海默病（AD）的患者与健康对照组（CTRL）相比，皮质下结构的体积和微观结构的进行性破坏。我们在一项横断面研究中结合了容积和弥散张量成像（DTI）技术，包括30例a-MCI，30例AD患者和30例年龄匹配的CTRL。我们采用了一种全自动的基于模型的分割算法，3特斯拉MRI解剖图像和准确的共配准的DTI解剖图像，以提取区域值的DTI参数。从CTRL到MCI再到AD，两个脑动脉的体积均显著且进行性降低。从对照组到AD，两个丘脑的体积都表现出进行性且显着的减少。平均扩散率（MD）值在三组的双侧海马，杏仁核，并在右侧尾状核逐渐增加。没有发现分数各向异性（FA）值的差异。两种不同但重叠的结构进展模式（即，萎缩）和微结构（即，MD增加）损伤。特别是，萎缩的模式反映了平均MD的增加值，这提供了轻度AD患者海马结构中细微组织破坏的进一步指标。结合不同的MRI模式可以识别AD患者皮层下区域发生的微妙致病机制的敏感指标。
The aim of this work was to investigate the hypothesis that multimodal MRI is able to detect the progressive disruption of volume and microstructure of subcortical structures in patients with amnestic mild cognitive impairment (a-MCI) and mild Alzheimer's disease (AD) in comparison with healthy controls (CTRL). We combined volumetric and diffusion tensor imaging (DTI) techniques in a cross-sectional study including 30 a-MCI, 30 AD patients, and 30 age-matched CTRL. We employed a fully automated model-based segmentation algorithm on 3 Tesla MRI anatomical images and accurate coregistration of DTI to anatomical images to extract regional values of DTI parameters. Both the hippocampi significantly and progressively decreased in volume from CTRL through MCI to AD. Both the thalami showed a progressive and significant decrease in volume from CTRL to AD. Mean diffusivity (MD) values increased progressively across the three groups in the bilateral hippocampus, amygdala, and in the right caudate. No differences in fractional anisotropy (FA) values were found. Two distinct but overlapping patterns of progression of structural (i.e., atrophy) and microstructural (i.e., MD increase) damage were observed. Particularly, the pattern of atrophy was mirrored by the increasing value of the averaged MD, which provided a further indicator of subtle tissue disruption in the hippocampal structure in mild AD patients. Combining different MRI modalities can allow identifying sensitive indicators of the subtle pathogenic mechanisms that occur in subcortical areas of AD patients.