三维锥形束CT解析重建算法发展综述

REVIEW OF RECENT DEVELOPMENT IN 3D CONE-BEAM CT RECONSTRUCTION ALGORITHMS

同二维的扇束、平行束相比,三维锥束CT需要的扫描时间更短,可以获得更好的空间分辨率和更高的射线利用效率。虽然锥束CT的解析重建算法在数学计算上比较复杂,由于其运算量较大,工程实现起来也有一定的困难,但是随着近几年硬件和算法的快速发展,三维锥束CT变得越来越有希望,医用及工业CT正向着中等甚至大锥角三维锥束CT过渡。鉴于其巨大的实用背景,本文对近些年三维锥束解析重建算法的发展做了一个回顾,尤其是针对长物体问题的算法及短物体问题的算法进行的研究,并对各类算法作了比较和讨论,最后对三维锥形束CT解析重建算法理论的发展进行了展望。

Compared with 2D Fan Beam or Parallel Beam Reconstruction, direct Cone Beam Reconstruction is able to achieve better spatial resolution and better utilization of photons. It also requires less scanning time. Though algorithms for direct Cone Beam Reconstruction are normally mathematically complex, they are becoming more and more practical with the great improvement of computer technology. Now CT systems used in medical diagnosis and industrial non-destructive detection are revoluting from small cone angle to moderate or even large cone angle 3D Cone Beam CT. Here we present a brief review of the recent development in Cone Beam Algorithms especially in long object algorithms. Then we make a discussion and comparison among these algorithms.