摘要
针对锥束ART算法重建速度慢的问题,提出了一种基于投影的三维射线与体素的快速遍历和求交算法。该算法将三维射线投影到两个互相垂直的平面上,通过计算投影线与投影平面的相交情况来确定三维射线穿过体素的索引及长度。利用该算法在图像重建过程中实时计算权因子,不仅节省了大量的内存空间,而且提高了投影和反投影运算的速度。基于该算法的特点,在重建过程中采用了一种按列优先的策略,减少了不必要的计算,大大提高了重建速度。仿真实验表明,该算法非常有效,与传统的Siddon算法相比取得了17倍以上的重建加速比。
To improve the reconstruction speed of cone-beam ART, this paper presents a fast algorithm based on projection for voxel traversal and intersection calculation along 3D ray. Firstly, the 3D ray is projected onto two perpendicular planes; then, the intersection situation between the projection line and planes is calculated; finally, the voxel index and length traversed by the 3D ray can be determined from the above intersection situation. Using this algorithm to calculate the weight coefficients during reconstructing on real-time can not only save large amount of memory, but also improve the speed of projection and back-projection. Based on the characteristic of the proposed algorithm, a strategy of processing column data first is used during reconstructing, thus unnecessary computation is reduced and the reconstruction speed is improved greatly. The result shows that the algorithm is very effective and the reconstruction speed is improved about 17 times compared with the conventional Siddon algorithm.
出处
《仪器仪表学报》
EI
CAS
CSCD
北大核心
2009年第4期887-892,共6页
Chinese Journal of Scientific Instrument
基金
国家自然科学基金(50375126)
陕西省教育厅专项基金(07JK425)资助项目
关键词
锥束CT
图像重建
ART算法
体素遍历
cone-beam CT
image reconstruction
algebraic reconstruction technique
voxel traversal
