Development of CT-Image Analysis System with Three-Dimensional Brain-Anatomy Data-Base

几种类型的CT，如X射线CT，MRI和正电子CT，用于诊断脑部疾病。这些CT是相辅相成的，对各种CT的互补数据分析将为建立新的脑疾病诊断系统做出巨大贡献。作为这一工作的第一步，本项目开发了一个三维脑解剖数据库和利用该数据库的结构分析算法，并证明该算法可以成功地分析正常脑的CT图像。此外，该项目还开发了一种先进的算法，该算法利用数据库从有限的二维CT横截面上的轮廓线重建脑解剖部分的三维结构，并通过将其应用于脑萎缩的视觉估计，证明了先进的重建算法在临床上是可用的。然而，上述结构分析算法，不能应用于一个完全变态的大脑。为了科普这个问题，本项目在图像处理工作站上集成了一个交互式CT图像分析系统。在该系统中，结构分析软件和交互式软件分别用C语言和工作站特有的图形语言编写。操作员可以通过使用交互式CT图像分析系统在五分钟内分析CT图像。此外，本计画已初步将互动式电脑断层影像分析系统应用于脑解剖结构的体积估测，初步研究显示互动式电脑断层影像分析系统具有提供临床可用资讯的潜力。

Several types of CT, such as X-Ray CT, MRI, and Positron-CT, are used for diagnoses of brain diseases. These CTs are complements each of the other, and complementary data analysis of various CTs will make a large contribution to the establishment of a new diagnostic system for brain diseases.As the first step of this, the project has developed a three-dimensional brain-anatomy data-base and a atructure-analysis algorithm utilizing the data-base, and proved that this algorithm can successfully analyze a CT-image of a normal brain. In addition, the project has developed an advanced algorithm which reconstructs three-dimensional structure of parts of brain anatomy from contour lines on a limited set of two-dimensional CT-cross section by utilizing the data-base, and demonstrated that advanced reconstruction algorithm is clinically available, through its application to visual estimation of cerebral atrophy.The above-mentioned structure-analysis algorithm, however, cannot be applied to a quite metamorphosed brain. To cope with this problem, this project has incorporated an enteractive CT-image analysis system as a software on an image-processing work-station. In this system, the structure-analysis software and the interactive software are written in the C-language and the graphics language peculiar to the workstation, respectively. An operator can analyze a CT-image within five minutes by using the interactive CT-image analysis system. Furthermore, this project has preliminarily applied the interactive CT-image analysis system to volum estimation of brain anatomies, and the preliminary investigation has demonstrated that the interactive CT-image analysis system has a potential for providing clinically available information.