Development of three-dimensional image programs for research and education of human embryology

这项研究的目的是制定计划，以协助人类胚胎学的研究和教育。为了观察人类胚胎发育过程中的形态变化，我们利用核磁共振显微镜等设备从标本中获取了三维图像，提取并显示了体外和体内器官的三维形状。结果表明：(1)京都大学先天性异常研究中心拥有大量的人类胚胎标本。我们已经开发了一个系统来检索和有效地展示标本，其中标本的形态特征可以相互比较或与标准的3D模型，通过查看3D图像。(2)上述部分标本以连续切片形式保存。我们开发了一个系统，从连续切片的标本重建三维形状，引入外部的照片，以提高重建的准确性。(3)为了辅助三维图像分析，我们开发了在三维标量场中显示等值面的拓扑关系，在三维数字图像中描述这种关系，并利用这种关系从三维图像中交互式地提取区域（标本图像的外部和内部器官）的程序。(4)我们建立了一个时空4D模型，不仅可以描述人类胚胎的形态变化，还可以描述内脏器官的出现和消失。利用这个模型，我们开发了一个程序来显示外部和内部器官的标准形状，以及通过程序提取的标本的形状(3)。

The purpose of this research is to develop programs to assist the research and education of human embryology. In order to view the morphological change in the development of human embryos, we have acquired tree-dimensional (3D) images from specimens using equipments such as MR microscopes, extracting and displaying the 3D shapes of external and internal organs. Our results areas follows:(1)Congenital Anomaly Research Center in Kyoto University has huge number of specimens of human embryo. We have developed a system to retrieve and display the specimens efficiently, where the morphological features of the specimens can be compared from each other or with a standard 3D model, by viewing 3D images.(2)A part of the specimens described above are stored as serial sections. We have developed a system to reconstruct 3D shapes from the serially sectioned specimens, introducing the photographs of outside to improve the accuracy of reconstruction.(3)In order to assist 3D image analysis, we have developed procedures to display the topological relationship of isosurfaces in 3D scalar field, to describe the relationship in 3D digital images, and to extract regions (external and internal organs for the images of specimens) interactively using the relationship from 3D images.(4)We have developed a spaciotemporal 4D model describing not only morphological change of a human embryo, but also appearance and disappearance of internal organs. Using this model, we have developed a program to display the standard shape of external and internal organs with those of specimens extracted by procedures (3).