Towards a practical implementation of the MLE algorithm for positron emission tomography

Conference · Sat Feb 01 04:00:00 EST 1986 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:5943232

Llacer, J; Andreae, S; Veklerov, E; Hoffman, E J

Recognizing that the quality of images obtained by application of the Maximum Likelihood Estimator (MLE) to Positron Emission Tomography (PET) and Single Photon Emission Tomography (SPECT) appears to be substantially better than those obtained by conventional methods, the authors have started to develop methods that will facilitate the necessary research for a good evaluation of the algorithm and may lead to its practical application for research and routine tomography. They have found that the non-linear MLE algorithm can be used with pixel sizes which are smaller than the sampling distance, without interpolation, obtaining excellent resolution and no noticeable increase in noise. They have studied the role of symmetry in reducing the amount of matrix element storage requirements for full size applications of the algorithm and have used that concept to carry out two reconstructions of the Derenzo phantom with data from the ECAT-III instrument. The results show excellent signal-to-noise (S/N) ratio, particularly for data with low total counts, excellent sharpness, but low contrast at high frequencies when using the Shepp-Vardi model for probability matrices.

• Research Organization: Lawrence Berkeley Lab., Univ. of California, Berkeley, CA 94720
• OSTI ID: 5943232
• Report Number(s): CONF-851009-
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: NS-33:1
• Country of Publication: United States
• Language: English

Related Subjects

550602* -- Medicine-- External Radiation in Diagnostics-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
ALGORITHMS
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
ECAT SCANNING
EMISSION COMPUTED TOMOGRAPHY
FREQUENCY DEPENDENCE
MATHEMATICAL LOGIC
MATHEMATICAL MODELS
MATRICES
MAXIMUM-LIKELIHOOD FIT
MEMORY DEVICES
NONLINEAR PROBLEMS
NUMERICAL SOLUTION
PHOTON EMISSION SCANNING
POSITRON COMPUTED TOMOGRAPHY
PROBABILITY
RESEARCH PROGRAMS
SIGNAL-TO-NOISE RATIO
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
SYMMETRY
TOMOGRAPHY