Investigating white matter fibre density and morphology using fixel-based analysis.
Investigating white matter fibre density and morphology using fixel-based analysis.
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DOI：
10.1016/j.neuroimage.2016.09.029
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发表时间：
2017-01-01
期刊：
影响因子：
5.7
通讯作者：
Connelly A
中科院分区：
文献类型：
--
作者：
Raffelt DA;Tournier JD;Smith RE;Vaughan DN;Jackson G;Ridgway GR;Connelly A
基于体素的扩散MRI数据分析越来越受欢迎。然而，大多数白色物质体素包含来自多个纤维群体（通常称为交叉纤维）的贡献，因此体素平均定量测量（例如，分数各向异性）不是纤维特异性的，并且具有较差的可解释性。使用高阶扩散模型，可以提取每个体素（“固定元素”）内的单个纤维群的纤维密度相关参数，并且统计学的最新进展使得能够对这些数据进行多学科分析。然而，单独研究体素内微观纤维密度并不能解释白色物质形态（例如纤维束的口径）的宏观差异。在这项工作中，我们引入了一种新的方法来调查后者，我们称之为固定的形态测量（FBM）。为了获得一个更完整的措施有关的总数量的白色物质轴突，信息内体素微观纤维密度和宏观形态必须结合起来。因此，我们提出的FBM方法作为一个完整的一部分，在一个全面的固定为基础的分析框架，调查纤维密度，纤维束形态（横截面）的措施，并结合测量纤维密度和横截面。我们进行了模拟，以证明所提出的措施，使用各种变换的数值纤维束幻影。最后，我们通过比较临床患者组和健康对照组提供了这样一个分析的例子，这表明所有三种措施提供了不同的和互补的信息。通过从两个来源获取信息，结合纤维密度和横截面测量可能对某些病理学更敏感，并且更直接可解释。固定元素被定义为体素内的特定纤维群。我们描述了一个全面的方法，固定为基础的分析（FBA）的白色的问题。提出了一种研究纤维束形态（横截面）的新方法。我们在临床队列中比较了纤维密度、横截面和联合测量。这三种不同的分析提供了独特但互补的信息。
Voxel-based analysis of diffusion MRI data is increasingly popular. However, most white matter voxels contain contributions from multiple fibre populations (often referred to as crossing fibres), and therefore voxel-averaged quantitative measures (e.g. fractional anisotropy) are not fibre-specific and have poor interpretability. Using higher-order diffusion models, parameters related to fibre density can be extracted for individual fibre populations within each voxel (‘fixels’), and recent advances in statistics enable the multi-subject analysis of such data. However, investigating within-voxel microscopic fibre density alone does not account for macroscopic differences in the white matter morphology (e.g. the calibre of a fibre bundle). In this work, we introduce a novel method to investigate the latter, which we call fixel-based morphometry (FBM). To obtain a more complete measure related to the total number of white matter axons, information from both within-voxel microscopic fibre density and macroscopic morphology must be combined. We therefore present the FBM method as an integral piece within a comprehensive fixel-based analysis framework to investigate measures of fibre density, fibre-bundle morphology (cross-section), and a combined measure of fibre density and cross-section. We performed simulations to demonstrate the proposed measures using various transformations of a numerical fibre bundle phantom. Finally, we provide an example of such an analysis by comparing a clinical patient group to a healthy control group, which demonstrates that all three measures provide distinct and complementary information. By capturing information from both sources, the combined fibre density and cross-section measure is likely to be more sensitive to certain pathologies and more directly interpretable. A fixel is defined as a specific fibre population within a voxel. We describe a comprehensive approach to fixel-based analysis (FBA) of white matter. A novel method to investigate fibre bundle morphology (cross-section) is presented. We compare fibre density, cross-section and a combined measure in a clinical cohort. The three different analyses give unique yet complementary information.
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影响因子：
3.3
作者：
Santis S;Assaf Y;Evans CJ;Jones DK
通讯作者：
Jones DK
影响因子：
5.7
作者：
de Groot M;Vernooij MW;Klein S;Ikram MA;Vos FM;Smith SM;Niessen WJ;Andersson JL
通讯作者：
Andersson JL
影响因子：
5.7
作者：
Bach, Michael;Laun, Frederik B.;Maier-Hein, Klaus H.
通讯作者：
Maier-Hein, Klaus H.
影响因子：
5.7
作者：
Calamante, Fernando;Masterton, Richard A. J.;Connelly, Alan
通讯作者：
Connelly, Alan
DOI：
10.1016/j.jmr.2011.09.022
发表时间：
1996-06-01
期刊：
JOURNAL OF MAGNETIC RESONANCE SERIES B
影响因子：
--
作者：
Basser, PJ;Pierpaoli, C
通讯作者：
Pierpaoli, C