CT系统参数标定的数学模型

Mathematical Model of Parameter Calibration of CT System

CT系统是医学诊断的重要工具.由于CT系统安装时往往存在误差,从而影响成像质量,因此需要对CT系统进行参数标定.根据给定的模板及其接收信息,提出了一个"纵横定位模型"确定旋转中心和旋转角度等参数.根据所求得的参数,使用滤波反投影重建算法进行图像重建.为了去除反投影算法的星状伪迹,使用了R-L滤波器,从而得到了图像的几何形状和位置.

The CT system is an important tool for medical diagnosis. Because the CT system often has errors in its installation, which affects the imaging quality, it is necessary to calibrate the parameters of the CT system. Based on the given template and its received information, we propose a ＂horizontal and vertical positioning model＂ to determine parameters such as the rotation center and the rotation angle. We use the filtered back projection reconstruction algorithm to perform image reconstruction based on the parameters obtained. In order to remove the star artifacts of the back-projection algorithm, we used an R-L filter to obtain the image geometry and position.