Paper
22 September 1998 Fast Bayesian estimation methods in emission tomography
Alvaro R. De Pierro
Author Affiliations +
Abstract
Since the beginning o the 80's, starting with the work by L. Shepp and Y. Vardi, the maximum likelihood approach using the expectation maximization (EM) algorithm has been a powerful tool to solve the estimation problem arising in emission computed tomography (ECT). Important drawbacks of this approach were: slowness of the EM algorithm and its inherent difficult to extend it to handle 'a priori' information. Recently, we presented a new EM-like algorithm, that is based on a decomposition by blocks, with one or more projections in each block, achieving a sped-up of tow orders of magnitudes. On the other hand, in 1995, we extended the EM algorithm, in a natural way, allowing regularization terms. In this article, we present the extension of our work to the case of regularized likelihood estimation; that is, a method that preserves the main properties of the one, but significantly faster, allowing fast Bayesian estimation in ECT. We illustrate the practical behavior of our method with PET simulations.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Alvaro R. De Pierro "Fast Bayesian estimation methods in emission tomography", Proc. SPIE 3459, Bayesian Inference for Inverse Problems, (22 September 1998); https://doi.org/10.1117/12.323789
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KEYWORDS
Expectation maximization algorithms

Positron emission tomography

Tomography

Mathematical modeling

Reconstruction algorithms

Computed tomography

Photons

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