Relating imaging indices of white matter integrity and volume in healthy older adults
Relating imaging indices of white matter integrity and volume in healthy older adults
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DOI：
10.1093/cercor/bhm080
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发表时间：
2008-02-01
期刊：
影响因子：
3.7
通讯作者：
Laurienti, Paul J.
中科院分区：
文献类型：
--
作者：
Hugenschmidt, Christina E.;Peiffer, Ann M.;Laurienti, Paul J.
与年龄相关的白质变化有可能深刻影响认知功能。事实上，使用分数各向异性 (FA) 测量白质完整性的磁共振成像 (MRI) 研究揭示了 FA 与老年人行为表现之间的正相关性。与这些结果相混淆的是影像学研究表明，某些区域出现与年龄相关的白质萎缩，这些区域显示出 FA 的改变，这表明扩散的变化可能只是组织损失的一个附带现象。在当前的研究中，结构磁共振技术被用来确定健康老年人白质完整性和体积减少之间的关系。数据表明，白质萎缩确实导致了某些区域的差异，但在调整萎缩后，大部分白质的 FA 仍显着下降。结果表明白质完整性和体积变化之间存在复杂的关系。 FA 似乎比容量损失对正常组织的变化更敏感，并且这些 FA 变化实际上可能先于某些大脑区域的白质萎缩。因此，检测早期白质改变的能力可能有助于开发有针对性的治疗方法，以预防或减缓与年龄相关的白质退化和相关的认知后遗症。
Age-related alterations in white matter have the potential to profoundly affect cognitive functioning. In fact, magnetic resonance imaging (MRI) studies using fractional anisotropy (FA) to measure white matter integrity reveal a positive correlation between FA and behavioral performance in older adults. Confounding these results are imaging studies demonstrating age-related white matter atrophy in some areas displaying altered FA, suggesting changes in diffusion may be simply an epiphenomenon of tissue loss. In the current study, structural MRI techniques were used to identify the relationship between white matter integrity and decreased volume in healthy aging adults. The data demonstrated that white matter atrophy did in fact account for differences in some areas, but significant FA decreases remained across much of the white matter after adjusting for atrophy. Results suggest a complex relationship between changes in white matter integrity and volume. FA appears to be more sensitive than volume loss to changes in normal appearing tissue, and these FA changes may actually precede white matter atrophy in some brain areas. As such, the ability to detect early white matter alterations may facilitate development of targeted treatments that prevent or slow age-related white matter degradation and associated cognitive sequelae.