光学学报, 2016, 36 (9): 0911009, 网络出版: 2016-09-09
相对平行直线扫描CT滤波反投影图像重建 下载: 550次
Filtered Back-Projection Image Reconstruction Algorithm for Opposite Parallel Linear CT Scanning
成像系统 计算机层析成像 图像重建 相对平行直线扫描 滤波反投影 有限角 imaging systems computed tomography image reconstruction opposite parallel linear scanning filtered back-projection limited angle
摘要
射线源和探测器作相对平行直线运动的计算机层析成像扫描系统(OPLCT)结构简单,成本低,易于实现便携或可移动的应用需求。该扫描方式的前期研究采用顺序子集-同时迭代重建算法,该算法存在图像重建时间长、不能实现快速成像等问题。从傅里叶积分定理出发,推导OPLCT滤波反投影(OPLFBP)图像重建算法。构建的一次直线扫描(1T)图像重建模型属于有限角问题,OPLFBP算法不能完全重建出目标图像;进一步提出多次线性扫描并构建了两次垂直(2T)和三次圆周均匀分布(3T)的CT直线扫描模型。1T、2T和3T模型下的仿真结果表明OPLFBP算法正确可行,且2T、3T扫描与相似参数下圆周扇束扫描滤波反投影算法得到的重建图像相近。
Abstract
The computed tomography setup for the opposite parallel linear scanning (OPLCT) of X-ray source and detectors is simple in structure and feasible to achieve portability or mobility. The order subset-simultaneous algebraic reconstruction algorithm has been used in the preliminary studies, but its image reconstruction time is too long to realize fast imaging. To address this problem, we proposed a filtered back-projection algorithm for OPLCT (OPLFBP) based on the Fourier’s theorem. A single translation (1T) model was constructed for image reconstruction, while this model results in limited angle problem and cannot completely reconstruct the object image using the OPLFBP algorithm. Further, a multiple translation (MT) model was proposed, and meanwhile, models for two orthogonal translations (2T) and three symmetrical translations (3T) were constructed respectively. The simulation results for the 1T, 2T and 3T modes show that the OPLFBP algorithm is effective, and the 2T and 3T scanning modes and the traditional circular scanning mode are comparable in terms of reconstrution time and image quality.
伍伟文, 全超, 刘丰林. 相对平行直线扫描CT滤波反投影图像重建[J]. 光学学报, 2016, 36(9): 0911009. Wu Weiwen, Quan Chao, Liu Fenglin. Filtered Back-Projection Image Reconstruction Algorithm for Opposite Parallel Linear CT Scanning[J]. Acta Optica Sinica, 2016, 36(9): 0911009.