CAJ | 학술논문

针对普通C形臂投影图像失真影响计算机辅助手术的精度和传统校正方法费时的问题,提出了一种基于摄像机视觉模型的方法来快速校正C形臂X射线投影失真图像.该方法通过分析C形臂X射线投影图像失真的来源和类型,把C形臂系统标定和投影失真图像校正融为一体,再利用视觉模型的Tsai法对其进行标定获取畸变参数,然后利用畸变参数对失真图像进行几何校正.实验结果表明,在放射源到探测器的距离为120cm时,最大误差为8.8个像素,放射源到探测器的距离为121cm时,最大误差为9.1个像素.放射源到探测器的距离变化18mm时,标定获得放射源到探测器的距离变化值为18.11mm,相差0.11mm,并且在不同姿态时C形臂投影失真图像校正结果具有稳定性.该方法的优点是减小了建立理想图像带来的误差,而且步骤简单,容易在线使用.
침대보통C형비투영도상실진영향계산궤보조수술적정도화전통교정방법비시적문제,제출료일충기우섭상궤시각모형적방법래쾌속교정C형비X사선투영실진도상.해방법통과분석C형비X사선투영도상실진적래원화류형,파C형비계통표정화투영실진도상교정융위일체,재이용시각모형적Tsai법대기진행표정획취기변삼수,연후이용기변삼수대실진도상진행궤하교정.실험결과표명,재방사원도탐측기적거리위120cm시,최대오차위8.8개상소,방사원도탐측기적거리위121cm시,최대오차위9.1개상소.방사원도탐측기적거리변화18mm시,표정획득방사원도탐측기적거리변화치위18.11mm,상차0.11mm,병차재불동자태시C형비투영실진도상교정결과구유은정성.해방법적우점시감소료건립이상도상대래적오차,이차보취간단,용역재선사용.
In view of the fact that the accuracy of computer-assisted surgery is impacted by the C-arm X-ray projection image distortion and the present distortion corrections are time-consuming, the paper proposes a visual model-based correction method for fast correction of C-arm X-ray projection distortion images. This method conducts the analysis of the sources and types of C-arm X-ray projection image distortion and treats the C-arm system calibration and projection distortion image correction as an integrate system firstly, and then, obtains the distortion parameters by using the Tsai method of visual model. Finally, the distortion images are corrected by using distortion parameters. The experimental results show that the maximum error is 8.81 pixels at 120cm between the X-ray source to the detector. The maximum error is 9.09 pixels at 121cm between the X-ray source to the detector. When the difference between the X-ray source to the detector is 18mm, the result obtained by using this method is 18.11mm and the error is 0.11mm. The results are stable when the C-arm is at different postures. The method has the advantages of elimination of ideal image errors, simplicity in steps, and easy online usage.