MLE reconstruction of a brain phantom using a Monte Carlo transition matrix and a statistical stopping rule

Conference · Mon Feb 01 04:00:00 EST 1988 · IEEE Trans. Nucl. Sci.; (United States)

OSTI ID:7057004

Veklerov, E; Llacer, J; Hoffman, E J

In order to study properties of the Maximum Likelihood Estimator (MLE) algorithm for image reconstruction in Positron Emission Tomography (PET), the algorithm is applied to data obtained by the ECAT-III tomograph from a brain phantom. The procedure for subtracting accidental coincidences from the data stream generated by this physical phantom is such that the resultant data are not Poisson distributed. This makes the present investigation different from other investigations based on computer-simulated phantoms. It is shown that the MLE algorithm is robust enough to yield comparatively good images, especially when the phantom is in the periphery of the field of view, even though the underlying assumption of the algorithm is violated. Two transition matrices are utilized. The first uses geometric considerations only. The second is derived by a Monte Carlo simulation which takes into account Compton scattering in the detectors, positron range, etc. in the detectors. It is demonstrated that the images obtained from the Monte Carlo matrix are superior in some specific ways. A stopping rule derived earlier and allowing the user to stop the iterative process before the images begin to deteriorate is tested. Since the rule is based on the Poisson assumption, it does not work well with the presently available data, although it is successful with computer-simulated Poisson data.

• Research Organization: Lawrence Berkeley Lab., Univ. of California, Berkeley, CA (US)
• OSTI ID: 7057004
• Report Number(s): CONF-871006-
• Conference Information: Journal Name: IEEE Trans. Nucl. Sci.; (United States) Journal Volume: 35:1
• Country of Publication: United States
• Language: English

Related Subjects

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46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
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655003* -- Medical Physics-- Dosimetry
99 GENERAL AND MISCELLANEOUS
990230 -- Mathematics & Mathematical Models-- (1987-1989)
ALGORITHMS
BASIC INTERACTIONS
BODY
BRAIN
CALCULATION METHODS
CENTRAL NERVOUS SYSTEM
COINCIDENCE METHODS
COMPTON EFFECT
COMPUTERIZED SIMULATION
COMPUTERIZED TOMOGRAPHY
COUNTING TECHNIQUES
DIAGNOSTIC TECHNIQUES
DIFFERENTIAL EQUATIONS
ELASTIC SCATTERING
ELECTROMAGNETIC INTERACTIONS
EMISSION COMPUTED TOMOGRAPHY
EQUATIONS
IMAGE PROCESSING
IMAGE SCANNERS
INTERACTIONS
ITERATIVE METHODS
MATHEMATICAL LOGIC
MATRICES
MAXIMUM-LIKELIHOOD FIT
MEASURING INSTRUMENTS
MOCKUP
MONTE CARLO METHOD
NERVOUS SYSTEM
NUMERICAL SOLUTION
ORGANS
PARTIAL DIFFERENTIAL EQUATIONS
PHANTOMS
POISSON EQUATION
POSITRON COMPUTED TOMOGRAPHY
PROCESSING
RADIATION DETECTORS
SCATTERING
SIMULATION
STRUCTURAL MODELS
TOMOGRAPHY