國家衛生研究院 NHRI:Item 3990099045/5636

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Please use this identifier to cite or link to this item: http://ir.nhri.org.tw/handle/3990099045/5636

Title:	New ray-driven system matrix for small-animal pinhole-SPECT with detector blur, geometric response and edge penetration modeling
Other Titles:	IEEE Nuclear Science Symposium Conference Record
Authors:	Wietholt, C;Hsiao, IT;Chen, CT;Ieee
Contributors:	Division of Medical Engineering Research
Abstract:	Iterative reconstruction of pinhole SPECT projection data acquired in preclinical animal imaging research benefits from modeling physical parameters of the imaging process. In this study, we developed a ray-driven system model that accounts for detector blur, the geometric response and edge penetration of the pinhole. GATE 2.2.0/GEANT 4 Monte Carlo simulations utilizing a tungsten knife-edge pinhole with an aperture diameter of 2 mm were applied to measure the pinhole point spread function (PSF) and to generate pinhole SPECT projection images of 2 different resolution phantoms (2.0 mm and 1.8 mm). The new Monte Carlo based PSF with edge penetration was compared to an ideal pinhole model without edge penetration. To conserve memory, the ray-driven system matrix was computed for one angle and rotation was performed by interpolating the radiotracer distribution within the object space. Detector symmetry and a bitwise incremental storage scheme were utilized for further reduction of memory requirements. Two system setups with a magnification of 7.2x and 2x were studied. Reconstruction results show an improvement in image quality and reconstruction resolution for the new pinhole PSF model. In the low magnification system operated at its resolution limits these improvements are more pronounced than in the high magnification system. The newly implemented ray-driven reconstruction method has great flexibility and offers to be a platform for further improvements such as non-uniform attenuation and scatter correction, and integration of detector misalignments in the system matrix.
Date:	2006-10
Relation:	Nuclear Science Symposium Conference Record, 2006. IEEE. 2006 Oct:3414-3419.
Link to:	http://dx.doi.org/10.1109/NSSMIC.2006.353735
Cited Times(WOS):	https://www.webofscience.com/wos/woscc/full-record/WOS:000288875603105
Appears in Collections:	[Others] Conference Papers/Meeting Abstract

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