Title :
Selection of projection set and the order of calculation in ordered subsets expectation maximization method
Author :
Takahashi, M. ; Ogawa, I.
Author_Institution :
Coll. of Eng., Hosei Univ., Tokyo, Japan
Abstract :
In ordered subsets expectation maximization (OS-EM) the projection data are grouped into subsets and a pixel in a reconstructed image is updated by using projections in each subset. The aim of the study is to analyze the relationship between the quality of images and the selection of subsets or the access order of calculation among the subsets. The image quality was assessed with the mean square error, chi-square error and newly proposed error measures defined in the frequency domain. The results showed the recovery speed of the low to middle frequency components of an image is increased by the access order in calculation, in which the total number of subsets is divided by two or three, and subsets are accessed with the order separating neighboring subsets as much as possible
Keywords :
errors; image reconstruction; iterative methods; medical image processing; positron emission tomography; single photon emission computed tomography; PET; SPECT; access order; chi-square error; frequency domain; image quality; mean square error; medical diagnostic imaging; neighboring subsets; nuclear medicine; ordered subsets expectation maximization method; Acceleration; Detectors; Frequency domain analysis; Frequency measurement; Image reconstruction; Iterative algorithms; Iterative methods; Mean square error methods; Pixel; Single photon emission computed tomography;
Conference_Titel :
Nuclear Science Symposium, 1997. IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
0-7803-4258-5
DOI :
10.1109/NSSMIC.1997.670584
