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A Monte Carlo study on quantification of scattering and edge penetration in a breastdedicated SPECT scanner with lofthole collimation.
- Source :
- Iranian Journal of Nuclear Medicine; Jul2023, Vol. 31 Issue 2, p119-128, 10p
- Publication Year :
- 2023
-
Abstract
- Introduction: Quantitative accuracy in SPECT is mainly affected by collimator penetration and scattering, particularly for high-energy imaging. Lofthole collimation offers superior performance in terms of penetration and scattering. Methods: In this research, the GATE Monte Carlo simulator was exploited to calculate edge penetration and scattering in the lofthole collimator using an inair and in-phantom point source of Tc-99m and I-123. The performance of the lofthole was then compared to that of a pinhole. Both lofthole and pinhole collimators were assumed to have the same geometry including an aperture diameter of 3.04 mm and an opening angle of 75°. Furthermore, the angular distribution of the scattering and penetration were investigated for a multilofthole collimator. Results: The results show that penetration, scattering, and sensitivity are all a function of the photon energy. The penetration and scattering of the pinhole are about 4% higher than that of the lofthole collimator, for Tc-99m SPECT. Compared to the Tc-99m, I-123 SPECT suffers from approximately 1.5- and 1.42-fold higher penetration and scatter fractions, respectively, for lofthole aperture. Moreover, the lofthole collimator presents a higher sensitivity compared with the pinhole (0.030 versus 0.023 for the Tc-99m SPECT). In addition, the findings exhibit a reduction in sensitivity by increasing the photon incidence angle. Both scattering and penetration fractions illustrate a decreasing trend across the angle of incidence. Conclusion: Compared to pinhole, the lofthole offers superior performance in terms of scattering and penetration for both low- and high-energy SPECT imaging. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 16812824
- Volume :
- 31
- Issue :
- 2
- Database :
- Complementary Index
- Journal :
- Iranian Journal of Nuclear Medicine
- Publication Type :
- Academic Journal
- Accession number :
- 170036213
- Full Text :
- https://doi.org/10.22034/IRJNM.2023.129010.1533