基于单幅X线图像和CT数据的2D/3D配准系统

2D/3D registration system based on single X-ray image and CT data

目的建立基于统一计算架构(CUDA)下以单幅X线图像及CT扫描数据为数据源的2D/3D配准系统,并应用于膝关节在体运动及植入假体稳定性研究。方法首先应用张正友标定法对采集X线图像设备进行标定;其次基于CUDA构架利用光线跟踪算法生成数字影像重建图像,以相关性函数为相似性测度计算2D/3D配准参数;最后以三维激光扫描仪所获得的点云数据进行3D/3D配准,以验证2D/3D配准结果。结果以标本整体位置变换进行配准实验,6自由度平均误差中,位移小于1mm,旋转小于1°。结论此2D/3D配准系统达到了运动检测精度的要求,可以作为研究膝关节运动情况和假体在体稳定性研究的计算平台。

Objective To build a 2D/3D registration system based on the compute unified device architecture（CUDA） frame with single X-ray image and CT data of knee joints and apply it in the research of knee motion and stability of implanted prosthesis.Method The digital radiography（DR） equipment used in the study was calibra-ted by the Zhang zhengyou Calibration Method,and then digitally rendered radiographs（DRR） images were gen-erated in the CUDA frame with light-tracing algorithm,and the best 2D/3D registration parameters were calculated with a similarity operator of cross correlation;finally,the results were evaluated by using the method of 3D/3D registration with data obtained from a 3D laser scanner.Results With knee specimen X-ray images and CT da-ta,in 6 degrees of freedom,the average errors of transform were below 1 mm,and those of rotation were below 1°.Conclusions The 2D/3D registration system can meet the precision requirement of motion detection and be used to study the knee motion and prosthesis location.