基于最小区域的锥束ART算法快速图像重建

针对锥束ART算法重建速度慢的问题,考虑到工业CT重建目标尺寸差异较大的特点,提出了一种基于最小重建区域的快速三维图像重建方法。由不同视角下的锥束投影构建最小区域包络,对最小区域包络进行膨胀处理,以消除重建目标边界附近所出现的伪影,在此基础上,给出了射线穿过最小重建区域的体素索引及权因子的计算。该方法能够根据重建目标的尺寸自适应地确定最小重建区域,从而最大限度地减少了计算量。实验结果表明,该方法不仅大幅度提高了锥束ART算法的重建速度,而且有效地提高了重建质量。

Fast image reconstruction for cone-beam ART based on minimal reconstruction region

To solve the slow reconstruction speed problem of cone-beam algebraic reconstruction technique (ART) algorithm,considering the characteristic of large difference of reconstruction objects of industrial computed tomography (CT) in size,a fast image reconstruction method based on minimal reconstruction region is proposed.The envelope of minimal region is constructed by cone-beam projection of different views.The envelope of minimal region is expanded to eliminate the artifact which exists near the boundary of reconstruction object.On this basis,the computation of voxel index and weight coefficient of ray traversing through the minimal reconstruction region is presented.The method can adaptively determine the minimal reconstruction region according to the size of reconstruction object,thus unnecessary computation is reduced farthest.Experimental results show that the proposed method can not only improve the reconstruction speed of ART greatly but also improve the reconstruction quality effectively.