The effects of incorrect modeling on noise and resolution properties of ML-EM images

Author

Wilson, D.W. ; Barrett, H.H.

Author_Institution

Dept. of Radiol., Arizona Univ., Tucson, AZ, USA

Volume

49

Issue

3

fYear

2002

fDate

6/1/2002 12:00:00 AM

Firstpage

768

Lastpage

773

Abstract

The effects of incorrect compensation for collimator blur in single-photon emission computed tomography (SPECT) images are studied in terms of the noise and resolution properties of the reconstructed images. Qualitative analysis of images of the largelyHoffman brain phantom reconstructed using nonlinear maximum-likelihood-expectation maximization (ML-EM) show the behavior of longer noise correlations for high-pass filtered images. These qualitative observations are confirmed with more quantitative noise measures. The differences also appear in images reconstructed using linear Landweber iteration. However, the signal-to-noise ratio, in terms of the noise-equivalent quanta, remains largely unchanged. We conclude that the compensation model affects SPECT image properties, though the effect on human task performance remains to be studied.

Keywords

iterative methods; maximum likelihood estimation; noise; single photon emission computed tomography; Hoffman brain phantom; ML-EM images; SPECT; high-pass filtered images; linear Landweber iteration; maximum-likelihood-expectation maximization images; noise; noise-equivalent quanta; resolution; signal-to-noise ratio; Collimators; Filters; Image reconstruction; Image resolution; Iterative algorithms; Optical imaging; Optical noise; Optical scattering; Reconstruction algorithms; Signal to noise ratio;

fLanguage

English

Journal_Title

Nuclear Science, IEEE Transactions on

Publisher

ieee

ISSN

0018-9499

Type

jour

DOI

10.1109/TNS.2002.1039561

Filename

1039561