Age-related differences in multiple measures of white matter integrity: A diffusion tensor imaging study of healthy aging.
Age-related differences in multiple measures of white matter integrity: A diffusion tensor imaging study of healthy aging.
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DOI：
10.1002/hbm.20872
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发表时间：
2010-03
影响因子：
4.8
通讯作者：
Howard, James H., Jr.
中科院分区：
文献类型：
--
作者：
Bennett, Ilana J.;Madden, David J.;Vaidya, Chandan J.;Howard, Darlene V.;Howard, James H., Jr.
扩散张量成像（DTI）测量分子水的扩散，其可用于计算白色物质完整性的指数。早期的DTI研究主要集中在两个整体的完整性措施;平均速率（平均扩散率，MD）和方向的一致性（分数各向异性，FA）的扩散。最近的研究增加了平行于主要扩散方向（轴向扩散率，AD）和垂直于主要扩散方向（径向扩散率，RD）的水运动的测量，这被认为反映了扩散中年龄差异的神经基础（即，轴突收缩和脱髓鞘）。在本研究中，白色物质完整性的年龄差异的模式进行了评估，通过比较年轻和健康的老年人的多项措施的完整性（FA，AD，RD）。结果揭示了两种常见的模式（仅径向增加和径向/轴向增加），以及一种相对新颖的模式（径向增加/轴向减少），其因脑区域而异，并可能反映微结构的差异老化（例如，髓鞘形成的程度）和宏观结构（例如，纤维取向的相干性）白色物质的性质。此外，额叶白色物质FA的较大年龄差异与白色物质完整性年龄差异的前后梯度一致。总之，这些发现补充了其他最近的研究，提供了有关健康老龄化特征的扩散率模式的信息。
Diffusion tensor imaging (DTI) measures diffusion of molecular water, which can be used to calculate indices of white matter integrity. Early DTI studies of aging primarily focused on two global measures of integrity; the average rate (mean diffusivity, MD) and orientation coherence (fractional anisotropy, FA) of diffusion. More recent studies have added measures of water movement parallel (axial diffusivity, AD) and perpendicular (radial diffusivity, RD) to the primary diffusion direction, which are thought to reflect the neural bases of age differences in diffusion (i.e., axonal shrinkage and demyelination, respectively). In the present study, patterns of age differences in white matter integrity were assessed by comparing younger and healthy older adults on multiple measures of integrity (FA, AD, RD). Results revealed two commonly reported patterns (Radial Increase Only and Radial/Axial Increase), and one relatively novel pattern (Radial Increase/Axial Decrease) that varied by brain region and may reflect differential aging of microstructural (e.g., degree of myelination) and macrostructural (e.g., coherence of fiber orientation) properties of white matter. In addition, larger age differences in FA in frontal white matter were consistent with the anterior-posterior gradient of age differences in white matter integrity. Together, these findings complement other recent studies in providing information about patterns of diffusivity that are characteristic of healthy aging.
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脑白质完整性介导了认知表现的成年年龄差异。
影响因子：
3.2
作者：
Madden DJ;Spaniol J;Costello MC;Bucur B;White LE;Cabeza R;Davis SW;Dennis NA;Provenzale JM;Huettel SA
通讯作者：
Huettel SA
影响因子：
5.7
作者：
Berman, JI;Mukherjee, P;Henry, RG
通讯作者：
Henry, RG
影响因子：
3.7
作者：
Hugenschmidt, Christina E.;Peiffer, Ann M.;Laurienti, Paul J.
通讯作者：
Laurienti, Paul J.
影响因子：
2.5
作者：
Marner, L;Nyengaard, JR;Pakkenberg, B
通讯作者：
Pakkenberg, B
影响因子：
4.2
作者：
Bucur, Barbara;Madden, David J.;Huettel, Scott A.
通讯作者：
Huettel, Scott A.