Boukadi Mariem, Marcotte Karine, Bedetti Christophe, Houde Jean-Christophe, Desautels Alex, Deslauriers-Gauthier Samuel, Chapleau Marianne, Boré Arnaud, Descoteaux Maxime, Brambati Simona M
Centre de Recherche de l'Institut Universitaire de Gériatrie de Montréal, Montreal, QC, Canada.
Département de Psychologie, Université de Montréal, Montreal, QC, Canada.
Front Neurosci. 2019 Jan 14;12:1055. doi: 10.3389/fnins.2018.01055. eCollection 2018.
High angular resolution diffusion imaging (HARDI)-based tractography has been increasingly used in longitudinal studies on white matter macro- and micro-structural changes in the language network during language acquisition and in language impairments. However, test-retest reliability measurements are essential to ascertain that the longitudinal variations observed are not related to data processing. The aims of this study were to determine the reproducibility of the reconstruction of major white matter fiber bundles of the language network using anatomically constrained probabilistic tractography with constrained spherical deconvolution based on HARDI data, as well as to assess the test-retest reliability of diffusion measures extracted along them. Eighteen right-handed participants were scanned twice, one week apart. The arcuate, inferior longitudinal, inferior fronto-occipital, and uncinate fasciculi were reconstructed in the left and right hemispheres and the following diffusion measures were extracted along each tract: fractional anisotropy, mean, axial, and radial diffusivity, number of fiber orientations, mean length of streamlines, and volume. All fiber bundles showed good morphological overlap between the two scanning timepoints and the test-retest reliability of all diffusion measures in most fiber bundles was good to excellent. We thus propose a fairly simple, but robust, HARDI-based tractography pipeline reliable for the longitudinal study of white matter language fiber bundles, which increases its potential applicability to research on the neurobiological mechanisms supporting language.
基于高角分辨率扩散成像（HARDI）的纤维束成像技术越来越多地应用于语言习得和语言障碍过程中语言网络白质宏观和微观结构变化的纵向研究。然而，重测信度测量对于确定观察到的纵向变化与数据处理无关至关重要。本研究的目的是使用基于HARDI数据的带解剖约束的概率纤维束成像和约束球面反卷积来确定语言网络主要白质纤维束重建的可重复性，并评估沿这些纤维束提取的扩散测量指标的重测信度。18名右利手参与者接受了两次扫描，间隔一周。在左右半球重建了弓状束、下纵束、额枕下束和钩束，并沿每条纤维束提取了以下扩散测量指标：分数各向异性、平均扩散率、轴向扩散率、径向扩散率、纤维方向数、流线平均长度和体积。所有纤维束在两个扫描时间点之间均显示出良好的形态重叠，大多数纤维束中所有扩散测量指标的重测信度良好至优秀。因此，我们提出了一种相当简单但稳健的基于HARDI的纤维束成像流程，该流程对于白质语言纤维束的纵向研究可靠，这增加了其在支持语言的神经生物学机制研究中的潜在适用性。
