Comparing a diffusion tensor and non-tensor approach to white matter fiber tractography in chronic stroke.
Comparing a diffusion tensor and non-tensor approach to white matter fiber tractography in chronic stroke.
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DOI：
10.1016/j.nicl.2015.03.007
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发表时间：
2015
影响因子：
4.2
通讯作者：
Boyd, L. A.
中科院分区：
文献类型：
--
作者：
Auriat, A. M.;Borich, M. R.;Snow, N. J.;Wadden, K. P.;Boyd, L. A.
关键词：
基于扩散张量成像（DTI）的纤维束成像已被用于证明中风后白质通路状态在功能相关方面的差异。然而，现在已知张量模型对人脑中绝大多数体素中发现的复杂纤维结构不敏感。无法解析体素内纤维方向可能对基于标准DTI的纤维束重建方法的实用性具有重要影响。现在可以使用新的无张量方法来识别体素内纤维方向。约束球形反卷积（CSD）是一种表征体素内扩散行为的方法。在当前研究中，我们对皮质脊髓束（CST）和胼胝体（CC）进行了基于DTI和CSD的纤维束重建，以验证以下假设：对复杂纤维方向的表征可能会提高纤维束重建的稳健性，并提高识别慢性中风患者功能相关的白质异常的敏感性。对27名慢性中风后参与者和12名健康对照者进行了扩散加权磁共振成像。使用基于DTI和CSD的纤维束成像重建了双侧的胼胝体通路和CST。计算了感兴趣纤维束的平均分数各向异性（FA）、表观扩散系数（ADC）、轴向扩散率（AD）和径向扩散率（RD）。还确定了重建纤维束的总数和体积。比较了组间（中风组、对照组）和方法间（CSD、DTI）的扩散指标。评估了中风后运动行为与扩散指标之间的关系。总体而言，对于CC和CST通路，CSD方法比基于DTI的方法识别出更多的纤维束。对于CC介导的纤维束，DTI和CSD之间的平均FA、ADC和RD存在差异。在这些纤维束中，我们使用CSD而非DTI发现中风组和健康对照组之间CC的FA存在差异。CSD在9名使用DTI未识别出纤维束的中风参与者中识别出了同侧CST通路。此外，CSD在几个指标（纤维束数量、纤维束体积、FA、ADC和RD）上区分了中风同侧和健康对照的非优势侧CST，而DTI仅在纤维束数量上检测到组间差异。在中风组中，与CSD重建的同侧CST和CC相比，运动行为与从DTI得出的较少扩散指标相关。在检测非优势侧健康对照和同侧CST之间的扩散特征差异方面，CSD优于基于DTI的纤维束成像。与DTI指标相比，CSD对微观结构组织特性的测量与更多的运动结果相关。我们的结果表明，使用无张量扩散建模方法来表征复杂纤维组织以研究中风后大脑中的白质通路具有潜在的实用性和功能相关性。
比较了中风参与者中的张量和无张量纤维束成像方法
无张量方法在更多中风患者中检测到白质纤维束
无张量方法能更好地识别白质异常
无张量方法揭示了白质与运动结果之间的关系
无张量方法是研究慢性中风的一种敏感的纤维束成像方法
Diffusion tensor imaging (DTI)-based tractography has been used to demonstrate functionally relevant differences in white matter pathway status after stroke. However, it is now known that the tensor model is insensitive to the complex fiber architectures found in the vast majority of voxels in the human brain. The inability to resolve intra-voxel fiber orientations may have important implications for the utility of standard DTI-based tract reconstruction methods. Intra-voxel fiber orientations can now be identified using novel, tensor-free approaches. Constrained spherical deconvolution (CSD) is one approach to characterize intra-voxel diffusion behavior. In the current study, we performed DTI- and CSD-based tract reconstruction of the corticospinal tract (CST) and corpus callosum (CC) to test the hypothesis that characterization of complex fiber orientations may improve the robustness of fiber tract reconstruction and increase the sensitivity to identify functionally relevant white matter abnormalities in individuals with chronic stroke. Diffusion weighted magnetic resonance imaging was performed in 27 chronic post-stroke participants and 12 healthy controls. Transcallosal pathways and the CST bilaterally were reconstructed using DTI- and CSD-based tractography. Mean fractional anisotropy (FA), apparent diffusion coefficient (ADC), axial diffusivity (AD), and radial diffusivity (RD) were calculated across the tracts of interest. The total number and volume of reconstructed tracts was also determined. Diffusion measures were compared between groups (Stroke, Control) and methods (CSD, DTI). The relationship between post-stroke motor behavior and diffusion measures was evaluated. Overall, CSD methods identified more tracts than the DTI-based approach for both CC and CST pathways. Mean FA, ADC, and RD differed between DTI and CSD for CC-mediated tracts. In these tracts, we discovered a difference in FA for the CC between stroke and healthy control groups using CSD but not DTI. CSD identified ipsilesional CST pathways in 9 stroke participants who did not have tracts identified with DTI. Additionally, CSD differentiated between stroke ipsilesional and healthy control non-dominant CST for several measures (number of tracts, tract volume, FA, ADC, and RD) whereas DTI only detected group differences for number of tracts. In the stroke group, motor behavior correlated with fewer diffusion metrics derived from the DTI as compared to CSD-reconstructed ipsilesional CST and CC. CSD is superior to DTI-based tractography in detecting differences in diffusion characteristics between the nondominant healthy control and ipsilesional CST. CSD measures of microstructure tissue properties related to more motor outcomes than DTI measures did. Our results suggest the potential utility and functional relevance of characterizing complex fiber organization using tensor-free diffusion modeling approaches to investigate white matter pathways in the brain after stroke. Compared tensor and tensor-free tractography methods in stroke participants Tensor-free method detected white matter tracts in more individuals with stroke Superior identification of white matter abnormalities with tensor-free method Relationship between white matter and motor outcome revealed with tensor-free method Tensor-free method is a sensitive tractography method for studying chronic stroke.
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DOI：
10.1097/npt.0b013e3182a3d353
发表时间：
2014-07
期刊：
Journal of neurologic physical therapy : JNPT
影响因子：
--
作者：
Borich MR;Brown KE;Boyd LA
通讯作者：
Boyd LA
影响因子：
3.7
作者：
Besseling, Rene M. H.;Jansen, Jacobus F. A.;Backes, Walter H.
通讯作者：
Backes, Walter H.
影响因子：
4.8
作者：
Jeurissen, Ben;Leemans, Alexander;Sijbers, Jan
通讯作者：
Sijbers, Jan
影响因子：
2.5
作者：
Kwon, Hyeok Gyu;Lee, Dong Gyu;Jang, Sung Ho
通讯作者：
Jang, Sung Ho
影响因子：
5.7
作者：
Borich, Michael R.;Wadden, Katie P.;Boyd, Lara A.
通讯作者：
Boyd, Lara A.