Centre for Developing Brain, Imperial College London and MRC Clinical Sciences Centre, Hammersmith Hospital, London W12 0NN, UK.
Cereb Cortex. 2012 May;22(5):1016-24. doi: 10.1093/cercor/bhr176. Epub 2011 Jul 19.
Preterm birth is a leading cause of cognitive impairment in childhood and is associated with cerebral gray and white matter abnormalities. Using multimodal image analysis, we tested the hypothesis that altered thalamic development is an important component of preterm brain injury and is associated with other macro- and microstructural alterations. T(1)- and T(2)-weighted magnetic resonance images and 15-direction diffusion tensor images were acquired from 71 preterm infants at term-equivalent age. Deformation-based morphometry, Tract-Based Spatial Statistics, and tissue segmentation were combined for a nonsubjective whole-brain survey of the effect of prematurity on regional tissue volume and microstructure. Increasing prematurity was related to volume reduction in the thalamus, hippocampus, orbitofrontal lobe, posterior cingulate cortex, and centrum semiovale. After controlling for prematurity, reduced thalamic volume predicted: lower cortical volume; decreased volume in frontal and temporal lobes, including hippocampus, and to a lesser extent, parietal and occipital lobes; and reduced fractional anisotropy in the corticospinal tracts and corpus callosum. In the thalamus, reduced volume was associated with increased diffusivity. This demonstrates a significant effect of prematurity on thalamic development that is related to abnormalities in allied brain structures. This suggests that preterm delivery disrupts specific aspects of cerebral development, such as the thalamocortical system.
早产是儿童认知障碍的主要原因，与大脑灰质和白质异常有关。使用多模态图像分析，我们检验了这样一个假设，即改变的丘脑发育是早产儿脑损伤的一个重要组成部分，并与其他宏观和微观结构改变有关。在足月年龄时，从 71 名早产儿中采集了 T1-和 T2-加权磁共振图像和 15 个方向的扩散张量图像。基于变形的形态测量学、基于束的空间统计学和组织分割技术被结合起来，对早产儿脑损伤对区域性组织体积和微观结构的影响进行了非主观的全脑调查。早产程度越高，丘脑、海马体、眶额叶、后扣带回和半卵圆中心的体积越小。在控制了早产因素后，丘脑体积的减小预测了皮质体积的降低；额叶和颞叶的体积减少，包括海马体，以及程度较小的顶叶和枕叶；皮质脊髓束和胼胝体的各向异性分数降低。在丘脑，体积的减小与扩散度的增加有关。这表明早产对丘脑发育有显著影响，与相关脑结构的异常有关。这表明早产会破坏大脑发育的特定方面，如丘脑皮质系统。
