Quantification of apparent axon density and orientation dispersion in the white matter of youth born with congenital heart disease
Quantification of apparent axon density and orientation dispersion in the white matter of youth born with congenital heart disease
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DOI：
10.1016/j.neuroimage.2019.116255
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发表时间：
2020-01-15
期刊：
影响因子：
5.7
通讯作者：
Brossard-Racine, Marie
中科院分区：
文献类型：
--
作者：
Easson, Kaitlyn;Rohlicek, Charles, V;Brossard-Racine, Marie
背景资料：白色物质的改变以前已被证明在青少年先天性心脏病（CHD）使用扩散张量成像（DTI）。然而，由于DTI指标的非特异性，很难解释这些发现的微观结构的影响。本研究探讨了使用神经突的方向分散和密度成像（NODDI），其中涉及到先进的多个b值数据的收购超过两个壳，并提供代理措施的明显轴突密度和方向分散内白色matters.Study设计的补充经典DTI measurements：青少年年龄16至24岁出生的复杂CHD和健康的同龄人进行了脑磁共振成像。比较两组的白色物质束体积和DTI和NODDI指标的束平均值。Tract-average DTI和NODDI结果在空间上得到证实，使用tract-based spatial statistics.Results：有广泛的区域较低的tract-average神经突密度指数（NDI）在CHD组相比，对照组，特别是在长的联合道和胼胝体的区域，伴随着较小的白色物质道体积和孤立的集群较低的分数各向异性（FA）。方向分散指数（ODI）组间无显着差异。结论轴索堆积的表观密度较低，但不改变轴索方向，是一个关键的微观结构因素，观察到的白色物质异常的青年先天性心脏病。这些轴突包装的损害可能是早期脑损伤和发育不良的持久后果，并可能解释这个高危人群所经历的一些长期神经心理学困难。
Background: White matter alterations have previously been demonstrated in adolescents born with congenital heart disease (CHD) using diffusion tensor imaging (DTI). However, due to the non-specific nature of DTI metrics, it is difficult to interpret these findings in terms of their microstructural implications. This study investigated the use of neurite orientation dispersion and density imaging (NODDI), which involves the acquisition of advanced multiple b-value data over two shells and provides proxy measures of apparent axon density and orientation dispersion within white matter, as a complement to classic DTI measures.Study design: Youth aged 16 to 24 years born with complex CHD and healthy peers underwent brain magnetic resonance imaging. White matter tract volumes and tract-average values of DTI and NODDI metrics were compared between groups. Tract-average DTI and NODDI results were spatially confirmed using tract-based spatial statistics.Results: There were widespread regions of lower tract-average neurite density index (NDI) in the CHD group as compared to the control group, particularly within long association tracts and in regions of the corpus callosum, accompanied by smaller white matter tract volumes and isolated clusters of lower fractional anisotropy (FA). There were no significant differences in orientation dispersion index (ODI) between groups.Conclusion Lower apparent density of axonal packing, but not altered axonal orientation, is a key microstructural factor in the white matter abnormalities observed in youth born with CHD. These impairments in axonal packing may be an enduring consequence of early life brain injury and dysmaturation and may explain some of the long-term neuropsychological difficulties experienced by this at-risk group.