基于FDK法的三维CT快速计算方法

在三维CT的图像重建过程中,单圆轨迹锥形束扫描是一种常用的方法,其算法普遍采用滤波反投影的形式(FBP)实现。由于滤波可以用FFT快速实现,因此反投影部分占据了计算的主要时间。论文提出同时从四个视角计算插值并作反投影累加,利用三角函数的周期性,减少传统算法中反投影阶段的乘法和正、余弦的计算次数,从而加快计算速度。分析和实验结果表明该方法对减少反投影计算所需的时间是行之有效的。

Fast Algorithm 3-D CT Based on FDK Method

Single circular orbit and filter backprojection is a common method in3-D CT.As filtering can be achieved by FFT,backprojection dominates the computation time.A new method is presented in this article in which the interpolation and backprojection in four views are performed.It can reduce the number of multiplication and computation of sine and cosine operations in traditional method based on the features of sine and cosine function.Example of implementation shows that the method is effective.