| Literature DB >> 18244025 |
D L Snyder, M I Miller, L J Thomas, D G Politte.
Abstract
Images produced in emission tomography with the expectation-maximization algorithm have been observed to become more noisy and to have large distortions near edges as iterations proceed and the images converge towards the maximum-likelihood estimate. It is our conclusion that these artifacts are fundamental to reconstructions based on maximum-likelihood estimation as it has been applied usually; they are not due to the use of the expectation-maximization algorithm, which is but one numerical approach for finding the maximum-likelihood estimate. In this paper, we develop a mathematical approach for suppressing both the noise and edge artifacts by modifying the maximum-likelihood approach to include constraints which the estimate must satisfy.Year: 1987 PMID： 18244025 DOI： 10.1109/TMI.1987.4307831
Source DB: PubMed Journal: IEEE Trans Med Imaging ISSN： 0278-0062 Impact factor: 10.048