摘要
在传统的CT系统中,系统的硬件成本和计算量都是非常巨大的．提出了一种利用偏移放置的面阵探测器的锥束CT系统,在这种系统中X射线束仅仅覆盖被扫描物体的一半体积,投影数据在探测器方向上是截断的,探测器尺寸和投影数据量都减少为传统CT系统的一半．在这种新型扫描方式下,现有的CT重建算法都不能处理．因此,提出了一种BPF形式的直接反投影重建方法．该方法不需要对投影数据重排,直接反投影滤波重建出最终的图像．因此,该算法在数学上更简洁,计算速度更快．最后,数值模拟实验和真实CT系统实验结果均验证了该系统和重建算法能够获得高质量的CT图像．
In a traditional cone-beam CT system, the cost of product and computation is very high. In this paper, we propose a transversely truncated cone-beam X-ray CT system with a reduced size detector positioned off-center, in which X-ray beams only cover half of the object. The reduced detector size cuts the cost and the X-ray dose of the CT system. The existing CT reconstruction algorithms are not directly applicable in this new CT system. Hence, we develop a BPF-type direct backprojection algorithm. Different from the traditional rebinning methods, our algorithm directly backprojects the pretreated projection data without rebinning. This makes the algorithm compact and computationally more efficient. Finally, some numerical simulations and practical experiments are done to validate the proposed algorithm.
出处
《高能物理与核物理》
CSCD
北大核心
2006年第8期812-817,共6页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金(10575059)教育部博士点基金(20030003074)资助~~
关键词
计算机断层成像
横向截断
PI线
反投影滤波(BPF)
直接反投影
computed tomography （CT）, transversely truncated, PI-line, backprojection filtered （BPF）, direct backprojection
