迭代成像中一种快速求解投影矩阵的方法

迭代成像中投影矩阵的获取速度直接影响算法的效率.本文提出了一种快速求解投影矩阵的方法,它尤其适用于扇形扫描投影数据的重建.利用扇形射束与重建图像像素的几何对称性一次获取多个投影矩阵的向量以及实时获取投影矩阵向量方式,减少了获得投影矩阵花费时间,节省了存储矩阵所占用的空间.通过模拟投影数据进行图像重建,其结果表明,该法较全部求出投影矩阵法极大地减少了内存空间的占用,较数据转换法节省了转换时间,从而提高了扇形投影数据的图像重建效率.

Fast obtainment method of projections matrix for iterative image reconstruction

A novel fast method of projections matrix solution for iterative image reconstruction, especially for image reconstruction from projections in fan scanning, was presented. The acquisition of multiple vectors for the projection matrix simultaneous by geometry symmetry, and the real-time acquisition of the vector of the projection matrix are adopted to shorten acquiring time and save the memory space of projection matrix. The experimental results of reconstruction from computer-generated projections successfully show that the proposed fast method occupies less memory space than the method which solves the whole projection matrix significantly. In addition, it spends less computational time than the transformation method from fan scanning to parallel scanning. Therefore the proposed fast solution can improve the efficiency of image reconstruction from projections in fan scanning.