Diffusion abnormality in posterior cingulate fiber tracts in Alzheimer's disease: tract-specific analysis
Diffusion abnormality in posterior cingulate fiber tracts in Alzheimer's disease: tract-specific analysis
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DOI：
10.1007/s11604-008-0258-3
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发表时间：
2008-10-01
影响因子：
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通讯作者：
Aoki, Shigeki
中科院分区：
文献类型：
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作者：
Nakata, Yasuhiro;Sato, Noriko;Aoki, Shigeki
目的.本研究的目的是通过扩散张量纤维束成像（DTT）确定阿尔茨海默病（AD）患者后扣带回纤维束（PCFT）的扩散异常。我们研究了23名AD患者和18名年龄匹配的正常对照者，他们使用扩散张量成像（DTI）进行磁共振成像。PCFT的DTT由DTI生成。平均扩散率（MD）和各向异性分数（FA）在共配准体素沿着与DTT的PCFT。AD组与正常对照组比较，采用t检验。AD患者PCFT的MD显著高于正常对照组（P = 0.019）。AD患者PCFT的FA值明显低于正常对照组（P = 0.007）。异常MD增加和FA减少，这被认为表明限制白色物质的水分子运动和组织各向异性的屏障的净损失，与神经病理学数据一致，这些数据表明AD脑的白色物质中髓鞘、轴突和寡树突细胞的部分损失。我们的研究结果表明，MD和FA反映了AD相关的组织病理学变化的PCFT的进展，并可能代表一个有用的生物学指标监测AD。
Purpose. The aim of this study was to determine diffusion abnormalities in the posterior cingulate fiber tracts (PCFTs) in patients with Alzheimer's disease (AD) by diffusion tensor tractography (DTT).Materials and methods. We studied 23 AD patients and 18 age-matched normal controls who underwent magnetic resonance imaging using diffusion tensor imaging (DTI). DTT of PCFTs was generated from DTI. Mean diffusivity (MD) and fractional anisotropy (FA) were measured in co-registered voxels along with DTT of PCFTs. Student's t-test was used to compare results between the AD patients and normal controls.Results. The MD in PCFTs was significantly higher in AD patients than in normal controls (P = 0.019). The FA in PCFTs was significantly lower in AD patients than in normal controls (P = 0.007).Conclusion. The abnormal MD increase and FA decrease, which is considered to indicate a net loss of barriers that restrict water molecular motion and tissue anisotropy of white matter, is consistent with neuropathological data that demonstrate partial loss of myelin, axons, and oligodendrial cells in white matter of AD brains. Our results suggest that MD and FA reflect progression of AD-related histopathological changes in the PCFTs and may represent a useful biological index for monitoring AD.