Developments with maximum likelihood X-ray computed tomography

Author

Browne, Jolyon A. ; Holmes, Timothy J.

Author_Institution

Dept. of Biomed. Eng., Rensselaer Polytech. Inst., Troy, NY, USA

Volume

11

Issue

1

fYear

1992

fDate

3/1/1992 12:00:00 AM

Firstpage

40

Lastpage

52

Abstract

An approach to the maximum-likelihood estimation of attenuation coefficients in transmission tomography is presented as an extension of earlier theoretical work by K. Lange and R. Carson (J. Comput. Assist. Tomography, vol.8, p.306-16, 1984). The reconstruction algorithm is based on the expectation-maximization (EM) algorithm. Several simplifying approximations are introduced which make the maximization step of the algorithm available. Computer simulations are presented using noise-free and Poisson randomized projections. The images obtained with the EM-type method are compared to those reconstructed with the EM method of Lange and Carson and with filtered backprojection. Preliminary results show that there are potential advantages in using the maximum likelihood approaches in situations where a high-contrast object, such as bone, is embedded in low-contrast soft tissue

Keywords

computerised tomography; Poisson randomized projection; attenuation coefficients; bone; computer simulations; low-contrast soft tissue; maximization step; maximum likelihood X-ray computed tomography; noise-free projection; transmission tomography; Attenuation; Biomedical measurements; Computed tomography; Extraterrestrial measurements; Image reconstruction; Maximum likelihood estimation; Positron emission tomography; Reconstruction algorithms; Stochastic processes; X-ray imaging;

fLanguage

English

Journal_Title

Medical Imaging, IEEE Transactions on

Publisher

ieee

ISSN

0278-0062

Type

jour

DOI

10.1109/42.126909

Filename

126909