Rose Stephen E, Janke Andrew L, Chalk Jonathan B
Centre for Magnetic Resonance, University of Queensland, Brisbane, Australia.
J Magn Reson Imaging. 2008 Jan;27(1):20-6. doi: 10.1002/jmri.21231.
To investigate microstructural changes in cortical and white matter pathways in patients with Alzheimer's disease using diffusion tensor imaging (DTI).
Measures of mean diffusivity (MD) and fractional anisotropy (FA) were compared in the brains of 13 Alzheimer's disease (AD) patients and a group of 13 aged-matched control participants employing an optimized DTI technique involving a fully automated, voxel-based morphometric (VBM) analysis.
After rigorous control for anatomical variation and confounding partial volume effects, we found significantly elevated MD measures within the hippocampus, amygdala, and medial temporal, parietal, and frontal lobe gray matter regions in the AD participants. The largest number of pixels with increased MD was localized bilaterally, within the posterior cingulate gyrus. The FA was significantly reduced within the thalamus, parietal white matter, and posterior limbs of the internal capsule, indicating significant involvement of corticothalamic and thalamocortical radiations.
This study demonstrates that rigorous VBM analysis of DTI data can be used to investigate microstructural changes in cortical, subcortical, and white matter regions in AD.
使用扩散张量成像（DTI）研究阿尔茨海默病患者皮质和白质通路的微观结构变化。
采用优化的DTI技术，包括全自动基于体素的形态计量学（VBM）分析，比较了13例阿尔茨海默病（AD）患者和13名年龄匹配的对照参与者大脑中的平均扩散率（MD）和分数各向异性（FA）测量值。
在严格控制解剖变异和混淆的部分容积效应后，我们发现AD参与者的海马体、杏仁核以及内侧颞叶、顶叶和额叶灰质区域内的MD测量值显著升高。MD增加的像素数量最多的部位是双侧的后扣带回。丘脑、顶叶白质和内囊后肢的FA显著降低，表明皮质丘脑和丘脑皮质辐射明显受累。
本研究表明，对DTI数据进行严格的VBM分析可用于研究AD患者皮质、皮质下和白质区域的微观结构变化。
