Zhou Fangxu, Chen Bohao, Chen Xi, Han Hua
School of Future Technology, University of Chinese Academy of Sciences, Beijing, China.
Institute of Automation, Chinese Academy of Sciences, Beijing, China.
Front Hum Neurosci. 2022 May 5;16:846599. doi: 10.3389/fnhum.2022.846599. eCollection 2022.
Registration of a series of the two-dimensional electron microscope (EM) images of the brain tissue into volumetric form is an important technique that can be used for neuronal circuit reconstruction. However, complex appearance changes of neuronal morphology in adjacent sections bring difficulty in finding correct correspondences, making serial section neural image registration challenging. To solve this problem, we consider whether there are such stable "markers" in the neural images to alleviate registration difficulty. In this paper, we employ the spherical deformation model to simulate the local neuron structure and analyze the relationship between registration accuracy and neuronal structure shapes in two adjacent sections. The relevant analysis proves that regular circular structures in the section images are instrumental in seeking robust corresponding relationships. Then, we design a new serial section image registration framework driven by this neuronal morphological model, fully utilizing the characteristics of the anatomical structure of nerve tissue and obtaining more reasonable corresponding relationships. Specifically, we leverage a deep membrane segmentation network and neural morphological physical selection model to select the stable rounded regions in neural images. Then, we combine feature extraction and global optimization of correspondence position to obtain the deformation field of multiple images. Experiments on real and synthetic serial EM section neural image datasets have demonstrated that our proposed method could achieve more reasonable and reliable registration results, outperforming the state-of-the-art approaches in qualitative and quantitative analysis.
将一系列脑组织的二维电子显微镜(EM)图像配准成三维形式是一项可用于神经元回路重建的重要技术。然而,相邻切片中神经元形态的复杂外观变化给寻找正确对应关系带来困难,使得连续切片神经图像配准具有挑战性。为了解决这个问题,我们考虑神经图像中是否存在这样稳定的“标记物”来减轻配准难度。在本文中,我们采用球形变形模型来模拟局部神经元结构,并分析两个相邻切片中配准精度与神经元结构形状之间的关系。相关分析证明,切片图像中的规则圆形结构有助于寻找稳健的对应关系。然后,我们设计了一个由这种神经元形态模型驱动的新的连续切片图像配准框架,充分利用神经组织解剖结构的特征,获得更合理的对应关系。具体来说,我们利用深度膜分割网络和神经形态物理选择模型来选择神经图像中稳定的圆形区域。然后,我们结合特征提取和对应位置的全局优化来获得多幅图像的变形场。在真实和合成的连续EM切片神经图像数据集上的实验表明,我们提出的方法可以实现更合理、可靠的配准结果,在定性和定量分析方面优于现有最先进的方法。