Title :
The use of maximum a posteriori and maximum likelihood transmission images for attenuation correction in PET
Author :
Ollinger, John M.
Author_Institution :
Washington Univ., Seattle, WA, USA
Abstract :
An algorithm for approximating the maximum a posteriori (MAP) estimate of transmission images is proposed. Attenuation correction factors can be formed from these images by reprojecting, sign-inverting and exponentiating them. The authors evaluate the quality of emission images of the myocardium as quantified by the average bias and variance for attenuation correction factors formed from unprocessed transmission scans, smoothed transmission scans. MAP images, and maximum-likelihood (ML) images. The MAP and ML methods yield emission images with significantly lower bias and variance than the other two methods. Moreover, they are relatively insensitive to the correction for accidental coincidences
Keywords :
computerised tomography; maximum likelihood estimation; medical image processing; radioisotope scanning and imaging; accidental coincidences; algorithm; attenuation correction factors; average bias; emission images; emission programs; maximum a posteriori images; maximum likelihood transmission images; myocardium; positron emission tomography; reprojecting; sign-inverting; smoothed transmission scans; unprocessed transmission scans; variance; Attenuation; Image reconstruction; Image segmentation; Iterative algorithms; Maximum likelihood estimation; Measurement errors; Myocardium; Positron emission tomography; Probability; Yield estimation;
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference, 1992., Conference Record of the 1992 IEEE
Conference_Location :
Orlando, FL
Print_ISBN :
0-7803-0884-0
DOI :
10.1109/NSSMIC.1992.301039
