Duan Dingna, Rekik Islem, Xia Shunren, Lin Weili, Gilmore John H, Shen Dinggang, Li Gang
Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang University, China.
Department of Radiology and BRIC, University of North Carolina at Chapel Hill, USA.
Proc IEEE Int Symp Biomed Imaging. 2017 Apr;2017:93-96. Epub 2017 Jun 19.
The dynamic development of brain cognition and motor functions during infancy are highly associated with the rapid changes of the convoluted cortical folding. However, little is known about how the cortical folding, which can be characterized on different scales, develops in the first two postnatal years. In this paper, we propose a curvature-based multi-scale method using spherical wavelets to map the complicated longitudinal changes of cortical folding during infancy. Specifically, we first decompose the cortical curvature map, which encodes the cortical folding information, into multiple spatial-frequency scales, and then measure the scale-specific wavelet power at 6 different scales as quantitative indices of cortical folding degree. We apply this method on 219 longitudinal MR images from 73 healthy infants at 0, 1, and 2 years of age. We reveal that the changing patterns of cortical folding are both scale-specific and region-specific. Particularly, at coarser spatial-frequency levels, the majority of the primary folds flatten out, while at finer spatial-frequency levels, the majority of the minor folds become more convoluted. This study provides valuable insights into the longitudinal changes of infant cortical folding.
婴儿期大脑认知和运动功能的动态发展与复杂的皮质折叠的快速变化高度相关。然而，对于在出生后的头两年中，可在不同尺度上表征的皮质折叠是如何发展的，人们却知之甚少。在本文中，我们提出了一种基于曲率的多尺度方法，使用球面小波来描绘婴儿期皮质折叠的复杂纵向变化。具体而言，我们首先将编码皮质折叠信息的皮质曲率图分解为多个空间频率尺度，然后在6个不同尺度上测量特定尺度的小波功率，作为皮质折叠程度的定量指标。我们将此方法应用于73名0岁、1岁和2岁健康婴儿的219张纵向磁共振图像上。我们发现皮质折叠的变化模式既有尺度特异性，也有区域特异性。特别是，在较粗的空间频率水平上，大多数主要褶皱变平，而在较细的空间频率水平上，大多数次要褶皱变得更加复杂。这项研究为婴儿皮质折叠的纵向变化提供了有价值的见解。
