【摘要】 锥束CT系统普遍采用滤波反投影(FDK)重建算法,该算法要求旋转工作台中心必须与FDK算法重建中心一致。受扫描系统安装定位精度限制,这一条件很难得到充分满足,从而引起重建切片图像出现伪影。为此,文章提出了一种基于细琴弦重建图像评估的黄金分割迭代搜索法来精确确定投影中心,还可确定射线源与旋转中心距离以及探测器安装旋转角、倾斜角等参数,实验证明了该方法的有效性。该方法对工业CT扫描系统的调试和校正具有重要意义。更多还原

【Abstract】 Confined by limited orientation precision due to mechanical errors,CBVCT system usually fails to meet the precondition that rotation center must be in accord with reconstruction center in widely adopted FDK algorithm,which arouses artifacts in reconstructed slices.This paper proposes an iterative golden section search method based on reconstructed slices evaluation of a string to achieve precise projection center,as well as detector’s rotate/tilt angle and distance from x-ray spot to rotate center.Experiments proves highly effectiveness,and well meets the requirement of registration and calibration in CT system.更多还原