基于体素模型的锥束CT仿真投影快速计算

Fast Calculation of Simulation Projection for Cone-beam CT Based on Voxel Phantom

在锥束CT图像重建算法研究中,通常利用计算机仿真方法生成理想的投影数据。针对体素模型下投影仿真速度慢的问题,提出了一种快速仿真投影计算方法。采用一种高效的射线与体素的遍历和求交算法来计算三维射线穿过体素的索引及长度,然后使用Intel处理器的单指令多数据(SIMD)技术,一次性加载4个体素数据,利用SSE技术实现了仿真投影的快速并行计算。实验结果表明文中提出的方法非常有效,在生成准确仿真投影数据的同时取得了3～5倍的加速比。

In the research of image reconstruction algorithm of cone - beam CT, computer simulation is usually used to generate ideal projection data. Aiming at the problem of slow speed of projection simulation for voxel phantom, a fast method for calculation of simulation projection is proposed in this paper. Firstly, we use an efficient algorithm of voxel traversal and intersection to calculate the voxel index and intersection length traversed by 3D ray; then, we use SIMD technique of Intel central process units to load four voxel data at one time and realize fast parallel calculation of simulation projection by SSE technique. Experimental result shows that the proposed method is very effective, we can generate accurate simulation projection data and get a speedup about 3 （5 times.