Zhong Suyu, He Yong, Gong Gaolang
State Key Laboratory of Cognitive Neuroscience and Learning & IDG/McGovern Institute for Brain Research, Beijing Normal University, Beijing, China.
Hum Brain Mapp. 2015 May;36(5):1995-2013. doi: 10.1002/hbm.22751. Epub 2015 Jan 30.
Using diffusion MRI, a number of studies have investigated the properties of whole-brain white matter (WM) networks with differing network construction methods (node/edge definition). However, how the construction methods affect individual differences of WM networks and, particularly, if distinct methods can provide convergent or divergent patterns of individual differences remain largely unknown. Here, we applied 10 frequently used methods to construct whole-brain WM networks in a healthy young adult population (57 subjects), which involves two node definitions (low-resolution and high-resolution) and five edge definitions (binary, FA weighted, fiber-density weighted, length-corrected fiber-density weighted, and connectivity-probability weighted). For these WM networks, individual differences were systematically analyzed in three network aspects: (1) a spatial pattern of WM connections, (2) a spatial pattern of nodal efficiency, and (3) network global and local efficiencies. Intriguingly, we found that some of the network construction methods converged in terms of individual difference patterns, but diverged with other methods. Furthermore, the convergence/divergence between methods differed among network properties that were adopted to assess individual differences. Particularly, high-resolution WM networks with differing edge definitions showed convergent individual differences in the spatial pattern of both WM connections and nodal efficiency. For the network global and local efficiencies, low-resolution and high-resolution WM networks for most edge definitions consistently exhibited a highly convergent pattern in individual differences. Finally, the test-retest analysis revealed a decent temporal reproducibility for the patterns of between-method convergence/divergence. Together, the results of the present study demonstrated a measure-dependent effect of network construction methods on the individual difference of WM network properties.
利用扩散磁共振成像,许多研究采用不同的网络构建方法(节点/边的定义)对全脑白质(WM)网络的特性进行了研究。然而,构建方法如何影响WM网络的个体差异,特别是不同方法是否能提供个体差异的趋同或不同模式,在很大程度上仍然未知。在此,我们应用10种常用方法在健康年轻成人人群(57名受试者)中构建全脑WM网络,其中涉及两种节点定义(低分辨率和高分辨率)和五种边的定义(二元、基于FA加权、基于纤维密度加权、长度校正纤维密度加权和连接概率加权)。对于这些WM网络,从三个网络方面系统地分析了个体差异:(1)WM连接的空间模式,(2)节点效率的空间模式,以及(3)网络全局和局部效率。有趣的是,我们发现一些网络构建方法在个体差异模式方面是趋同的,但与其他方法不同。此外,方法之间的趋同/不同在用于评估个体差异的网络属性中也有所不同。特别是,具有不同边定义的高分辨率WM网络在WM连接和节点效率的空间模式上显示出趋同的个体差异。对于网络全局和局部效率,大多数边定义的低分辨率和高分辨率WM网络在个体差异上始终呈现出高度趋同的模式。最后,重测分析显示了方法间趋同/不同模式具有良好的时间可重复性。总之,本研究结果证明了网络构建方法对WM网络属性个体差异的测量依赖效应。