Guevara M, Roman C, Houenou J, Duclap D, Poupon C, Mangin J-F, Guevara P
Annu Int Conf IEEE Eng Med Biol Soc. 2016 Aug;2016:1115-1119. doi: 10.1109/EMBC.2016.7590899.
The Human brain connection map is far from being complete. In particular the study of the superficial white matter (SWM) is an unachieved task. Its description is essential for the understanding of human brain function and the study of pathogenesis triggered by abnormal connectivity. In this work we expanded a previously developed method for the automatic creation of a whole brain SWM bundle atlas. The method is based on a hybrid approach. First a cortical parcellation is used to extract fibers connecting two regions. Then an intra-and inter-subject hierarchical clustering are applied to find well-defined SWM bundles reproducible across subjects. In addition to the fronto-parietal and insula regions of the left hemisphere, the analysis was extended to the temporal and occipital lobes, including all their internal regions, for both hemispheres. Validation steps are performed in order to test the robustness of the method and the reproducibility of the obtained bundles. First the method was applied to two independent groups of subjects, in order to discard bundles without match across the two independent atlases. Then, the resulting intersection atlas was projected on a third independent group of subjects in order to filter out bundles without reproducible and reliable projection. The final multi-subject U-fiber atlas is composed of 100 bundles in total, 50 per hemisphere, from which 35 are common to both hemispheres. The atlas can be used in clinical studies for segmentation of the SWM bundles in new subjects, and measure DW values or complement functional data.
人类大脑连接图谱远未完善。特别是,对脑浅表白质(SWM)的研究仍是一项未完成的任务。其描述对于理解人类大脑功能以及研究由异常连接引发的发病机制至关重要。在这项工作中,我们扩展了一种先前开发的用于自动创建全脑SWM束图谱的方法。该方法基于一种混合方法。首先,利用皮质分区来提取连接两个区域的纤维。然后应用受试者内和受试者间的层次聚类来找到在不同受试者间可重复的明确SWM束。除了左半球的额顶叶和岛叶区域外,分析还扩展到了颞叶和枕叶,包括两个半球的所有内部区域。执行验证步骤以测试该方法的稳健性以及所获得束的可重复性。首先,将该方法应用于两组独立的受试者,以剔除在两个独立图谱中不匹配的束。然后,将所得的交集图谱投影到第三组独立的受试者上,以滤除没有可重复且可靠投影的束。最终的多受试者U纤维图谱总共由100个束组成,每个半球50个,其中35个是两个半球共有的。该图谱可用于临床研究,对新受试者的SWM束进行分割,并测量扩散加权(DW)值或补充功能数据。