EMアルゴリズムと画像再構成 Image reconstruction using EM algorithm
Maximum likelihood criterion accounting for statistical behavior of photon is very useful for image reconstruction from projection at low count rate. EM (expectation maximization) algorithm is a powerful tool which provides such a maximum likelihood estimator successfully. In this article, the fundamental algorithms for emission and transmission image reconstruction originally proposed by Lange and Carson are reviewed. Here the likelihood incorporating the Poisson nature of photon counting is formulated and the procedure of the EM algorithm for maximizing the likelihood is shown.
放射線医学物理 19(3), 162-173, 1999-09-30
Japan Society of Medical Physics