The influence of complex white matter architecture on the mean diffusivity in diffusion tensor MRI of the human brain.
The influence of complex white matter architecture on the mean diffusivity in diffusion tensor MRI of the human brain.
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DOI：
10.1016/j.neuroimage.2011.09.086
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发表时间：
2012-02-01
期刊：
影响因子：
5.7
通讯作者：
Leemans A
中科院分区：
文献类型：
--
作者：
Vos SB;Jones DK;Jeurissen B;Viergever MA;Leemans A
在扩散张量磁共振成像(DT-MRI)中，关于复杂纤维结构(当图像体素包含具有多个主要方向的纤维群)的限制是众所周知的。分数各向异性(FA)值在这些区域较低，因为体素尺度上的扩散方向性较低，这使得对FA的解释不那么直接。此外，当一个体素内有一个以上的主导纤维方向时，轴向和径向扩散系数的解释远非微不足道。在这项工作中，使用(I)理论考虑，(Ii)模拟和(Iii)实验数据，证明了在复杂的白质构型中，与在体素内有单一主导纤维取向的组织相比，平均扩散系数(或扩散张量的轨迹)更低。我们表明，这种减少的幅度取决于各种因素，包括配置和微结构属性(例如，不同纤维种群的相对贡献)和获取设置(例如，b值)。这些结果增加了我们对从DT-MRI获得的定量指标的理解，特别是微观结构对平均扩散系数的影响。更重要的是，它们强化了一种日益增长的意识，即需要谨慎地解释DT-MRI指标的差异。
In diffusion tensor magnetic resonance imaging (DT-MRI), limitations concerning complex fiber architecture (when an image voxel contains fiber populations with more than one dominant orientation) are well-known. Fractional anisotropy (FA) values are lower in such areas because of a lower directionality of diffusion on the voxel-scale, which makes the interpretation of FA less straightforward. Moreover, the interpretation of the axial and radial diffusivities is far from trivial when there is more than one dominant fiber orientation within a voxel. In this work, using (i) theoretical considerations, (ii) simulations, and (iii) experimental data, it is demonstrated that the mean diffusivity (or the trace of the diffusion tensor) is lower in complex white matter configurations, compared with tissue where there is a single dominant fiber orientation within the voxel. We show that the magnitude of this reduction depends on various factors, including configurational and microstructural properties (e.g., the relative contributions of different fiber populations) and acquisition settings (e.g., the b-value). These results increase our understanding of the quantitative metrics obtained from DT-MRI and, in particular, the effect of the microstructural architecture on the mean diffusivity. More importantly, they reinforce the growing awareness that differences in DT-MRI metrics need to be interpreted cautiously.
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影响因子：
5.7
作者：
Fillard, Pierre;Descoteaux, Maxime;Poupon, Cyril
通讯作者：
Poupon, Cyril
影响因子：
3.3
作者：
Assaf, Y;Ben-Bashat, D;Cohen, Y
通讯作者：
Cohen, Y
DOI：
10.1097/rmr.0b013e31821e56ac
发表时间：
2010-04-01
期刊：
Topics in magnetic resonance imaging : TMRI
影响因子：
--
作者：
Jones, Derek K
通讯作者：
Jones, Derek K
影响因子：
3.3
作者：
Leemans, Alexander;Jones, Derek K.
通讯作者：
Jones, Derek K.
影响因子：
3.3
作者：
Alexander, AL;Hasan, KM;Parker, DL
通讯作者：
Parker, DL