Determination of weighting functions for energy-weighted acquisition

Journal Article · Fri Feb 01 00:00:00 EST 1991 · Journal of Nuclear Medicine; (USA)

OSTI ID:5929200

DeVito, R P; Hamill, J J ^[1]

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1. Siemens Gammasonics, Inc., Hoffman Estates, IL (USA)

Energy-weighted acquisition (EWA) is an image filtering technique, with a different spatial filter (weighting function) for each energy. The imaging characteristics of EWA are governed by the weighting functions used during the acquisition of the image. The determination of weighting functions is more complicated than the determination of energy windows in conventional imaging because the number of degrees of freedom is much greater. A methodology by which weighting functions can be produced is described. The weighting function is determined by minimizing a generalized chi-square with variable contributions from coefficients quantifying key image characteristics, e.g., signal-to-noise ratio, spatial resolution, and scatter fraction. Varying the importance of these characteristics gives us a workable function-generation tool, able to address a variety of clinical needs. The resulting weighting functions exhibit good scatter reduction properties at various scatter depths, as demonstrated by measurements of line source response functions in a scattering medium at depths from 5 to 14 cm. Energy weighting can also be used to compensate for collimator penetration from high energy gamma rays. Weighting functions are tested in the laboratory using both planar and SPECT phantoms.

• OSTI ID: 5929200
• Journal Information: Journal of Nuclear Medicine; (USA), Vol. 32:2; ISSN 0161-5505
• Country of Publication: United States
• Language: English

Related Subjects

61 RADIATION PROTECTION AND DOSIMETRY
IMAGE PROCESSING
WEIGHTING FUNCTIONS
GAMMA CAMERAS
MAN
PHANTOMS
SCATTERING
SIGNAL-TO-NOISE RATIO
SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY
SPATIAL RESOLUTION
ANIMALS
CAMERAS
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC TECHNIQUES
EMISSION COMPUTED TOMOGRAPHY
FUNCTIONS
MAMMALS
MOCKUP
PRIMATES
PROCESSING
RESOLUTION
STRUCTURAL MODELS
TOMOGRAPHY
VERTEBRATES
655003* - Medical Physics- Dosimetry