، صفحه 0-0 (1)

عنوان دوره: اولین دوره بین المللی و بیست و هشتمین دوره ملی (1400)

In SPECT, scattering and penetration of photons in the collimator result in considerable image degradation. A new version of pinhole collimation is proposed to address the problem. The aim of this study is, therefore, to quantify such effects for the lofthole collimator. In this study, the GATE Monte Carlo simulation was performed to calculate edge penetration and scattering in a breast SPECT scanner equipped with a multi-lofthole collimator. Simulations were carried out for a point source of Tc-99m in the different positions and the scattering and penetration factors are then calculated as a function of incidence angle. A comparison with a pinhole collimator was also conducted. The results illustrate a reduction in the sensitivity by increasing the photon incidence angle. Both scattering and penetration fractions exhibit a decreasing trend across the angle of incidence. In conclusion, the lofthole offers superior performance compared to the traditional pinhole collimators.

SPECT؛ penetration؛ Scattering؛ Collimator؛ Multi-lofthole؛ GATE