基于Radon逆变换的CT系统参数标定及成像分析

Parameter Calibration and Imaging Analysis of CT System Based on Radon Inversion

针对计算机断层成像(CT)系统安装时存在误差,导致机械系统无法实现精确扫描而影响成像质量的问题,提出基于Radon逆变换的CT系统参数标定及成像分析.使用CT图像重建、微分方程及改良的遗传算法等理论,建立正弦投影图、定点吸收率、精度及稳定性分析等模型.模拟结果表明,所建模型可有效测得未知介质的几何形状及定点吸收率,提高CT系统扫描轨迹的精度.基于质心法改进模板,可提高CT系统标定精度和稳定性,具有较好的可行性和实用性.

To solve problem of the image quality caused by installation error of CT imaging system,which resulting imprecise scanning of mechanical system,parameter calibration and imaging analysis based on Radon inversion were raised.The models of sinusoidal projection,fixed-point absorption rate and precision and stability analysis were established with the theory of CT image reconstruction,differential equation and improved genetic algorithm.The simulation results show that the method can effectively measure geometrical shape and fixed-point absorption rate of unknown medium and improve the accuracy of CT system scanning trajectory.The model was improved based on centroid method,which can advance calibration accuracy and stability of CT system and has good feasibility and practicality.