锥束X-CT系统四椭圆法获取全几何参数的研究  

Study on Four-elliptic Method of Cone Beam X-CT System to Obtain Full Geometric Parameters

作　　者：张震 宋卫东[1] 张丰收[1] ZHANG Zhen;SONG Weidong;ZHANG Fengshou(School of Medical Technology and Engineering,Henan University of Science and Technology,Luoyang 471000,Henan,P.R.China)

机构地区：[1]河南科技大学医学技术与工程学院

出　　处：《影像科学与光化学》2019年第6期554-563,共10页Imaging Science and Photochemistry

基　　金：国家科技部专项(2017YFB0306401)资助

摘　　要：锥束CT具有成像质量高、低辐射、操作简单等优点,近几年得到迅速发展。锥束CT几何参数的精确获取是得到高质量图像的关键因素。针对FDK算法要求的条件以及现有的几何参数获取方法,本文提出了一种基于四椭圆快速获取全参数的方法。首先介绍了锥束CT中的关键参数,然后提出了四椭圆全参数获取原理并设计出通用标定模体。本标定模体可用于任何锥角不同的锥束CT系统。通过标定模体在空间的几何关系获取系统中所有几何参数。最后针对该方法进行了实验论证,结果表明,本方法获取的几何参数精度高。综上所述,可证实该算法具有一定的工程实用价值。Cone beam CT has the advantages of high image quality,low radiation,and simple operation.It has developed rapidly in recent years.Accurate acquisition of geometric parameters of cone beam CT is a key factor in obtaining high quality images.Aiming at the conditions required by the FDK algorithm and the methods of acquiring geometric parameters,this paper proposes a method for quickly obtaining full parameters based on four ellipse.Firstly,the key parameters of cone beam CT are introduced.Then the principle of four ellipse full parameter acquisition is proposed and the universal calibration mode is designed.The calibration phantom can be used in any cone beam CT system with different cone angles.Accurately acquire all geometric parameters in the system by calibrating the geometric relationship of the phantom in space.Finally,the experimental demonstration is carried out for the method.The experimental results show that the geometric parameters obtained by this method have high precision,and the algorithm has certain engineering practical value.

关 键 词：锥束CT 数学模型 几何参数 标定模体 

分 类 号：G63[文化科学—教育学]