Title :
On the relation between the ISRA and the EM algorithm for positron emission tomography
Author :
De Pierro, Alvaro R.
Author_Institution :
Inst. de Matematica Estatistica, e Ciencia da Computacao, Univ. Estadual de Campinas, Sao Paulo, Brazil
fDate :
6/1/1993 12:00:00 AM
Abstract :
The image space reconstruction algorithm (ISRA) was proposed as a modification of the expectation maximization (EM) algorithm based on physical considerations for application in volume emission computered tomography. As a consequence of this modification, ISRA searches for least squares solutions instead of maximizing Poisson likelihoods as the EM algorithm. It is shown that both algorithms may be obtained from a common mathematical framework. This fact is used to extend ISRA for penalized likelihood estimates
Keywords :
computerised tomography; radioisotope scanning and imaging; Poisson likelihoods maximization; expectation maximization algorithm; image space reconstruction algorithm; least squares solutions; medical diagnostic imaging; nuclear medicine; penalized likelihood estimates; volume emission computered tomography; Chemistry; Computed tomography; Electrical capacitance tomography; Electron emission; Image reconstruction; Least squares methods; Physiology; Positron emission tomography; Reconstruction algorithms; Single photon emission computed tomography;
Journal_Title :
Medical Imaging, IEEE Transactions on
