Efficient solving algorithm for determining the exact sampling condition of limited-angle computed tomography reconstruction

Li, Ziheng; Wang, Linyuan; Zhang, Wenkun; Cai, Ailong; Li, Lei; Liang, Ningning; Yan, Bin

doi:10.3233/xst-180455

Cited by 2 publications

(1 citation statement)

References 29 publications

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“…1,2 Compared with the analytic reconstruction algorithms, [3][4][5][6][7] the iterative reconstruction algorithms can model physical parameters such as X-ray spectrum and focal spot blur, make better use of prior information of the reconstructed images and the projection data obtained by various acquisition methods, generate images with high signal-to-noise ratio at the same dose, and realize local reconstruction with truncated projection data. [8][9][10][11][12][13] The iterative reconstruction algorithms have many advantages that the analytic algorithms do not have, but they need a lot of computing and storage space to get the weighting factor accurately and efficiently, and have higher requirements for computer hardware.…”

Section: Introductionmentioning

confidence: 99%

New calculation method for exact length weighting factor in cone‐beam computed tomography

Wang

Jiang

2021

Int J Imaging Syst Tech

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In iterative reconstruction algorithms, it is very important to calculate the weighting factor quickly and accurately, which directly affects the reconstruction efficiency and accuracy of computed tomography images. In this paper, a new calculation method for accurate length weighting factor is developed. Firstly, the ray equation is determined according to the coordinates of the source and the ray's projection. Second, the intersections of the ray and the equidistant parallel planes along three coordinate axes are calculated, and the points intersecting with the reconstructed object are put into a set. Finally, when the X-axis coordinates of all points in the set are different, the points are arranged according to their X-axis coordinates; when the X-axis coordinates of all points are same, the points are arranged according to their Y-axis coordinates. The sorted point set is the intersections that the ray traverses the reconstructed object in sequence. The index and weighting factor of all voxels that the ray passes through can be determined by the sorted point set. Compared with the classical Siddon's method, it avoids the step of describing the intersections with parameters, and its calculation speed is increased by nearly 20%. The numerical simulations and real data reconstruction experiments are conducted to validate the proposed calculation method of exact length weighting factor.

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