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Methods to Improve Convergence Rate of Statistical Reconstruction Algorithm in Transmission CT

Journal of The Korea Internet of Things Society / Journal of The Korea Internet of Things Society, (P)2799-4791;
2024, v.10 no.3, pp.25-33
https://doi.org/10.20465/kiots.2024.10.3.025
Min-Gu Song

Abstract

In tomographic image reconstruction, the focus is on developing CT image reconstruction methods that can maintain high image quality while reducing patient radiation exposure. Typically, statistical image reconstruction methods have the ability to generate high-quality and accurate images while significantly reducing patient radiation exposure. However, in cases like CT image reconstruction, which involve multi-dimensional parameter estimation, the degree of the Hessian matrix of the penalty function is very large, making it impossible to calculate. To solve this problem, the author proposed the PEMG-1 algorithm. However, the PEMG-1 algorithm has issues with the convergence speed, which is typical of statistical image reconstruction methods, and increasing the penalty log-likelihood. In this study, we propose a reconstruction algorithm that ensures fast convergence speed and monotonic increase in likelihood. The basic structure of this algorithm involves sequentially updating groups of pixels instead of updating all parameters simultaneously with each iteration.

keywords
투과형 토머그래피, EM 알고리즘, EMG 알고리즘, PEMG-1 알고리즘, PPS-PEMG 알고리즘

Journal of The Korea Internet of Things Society