نوع مقاله : مقاله پژوهشی
نویسندگان
گروه فیزیک، دانشکده علوم، دانشگاه محقق اردبیلی، اردبیل، ایران
کلیدواژهها
موضوعات
عنوان مقاله English
نویسندگان English
One of the most important factors affecting the quality of images obtained from a SPECT imaging system is the physical characteristics of the collimator used. The aim of this study is to investigate the different components of the response of existing parallel-hole collimators (geometric, penetration, and scattering components) to the emission energies used in nuclear medicine imaging, and also to optimize the collimator parameters to achieve the highest value of the geometric component for high energies. The results of this study show that, considering the contribution of the geometric component, for emission energies of 68, 93, 135, 140, 159, 161, and 171 keV, the low-energy collimators LEHR and LEGP, for energies of 185 keV and 245 keV, the medium-energy collimators MEGP, and for energy of 300 keV, the high-energy collimators HEGP have the necessary efficiency. In contrast, for energies of 364 keV and 511 keV, the geometric response of any of the existing collimators is not sufficient. Hence, optimization of the collimator parameters for these two energies is necessary. According to the optimization results, high-energy collimators with the same hole size of 0.25 cm, the distance between the holes of 0.225 cm and 0.35 cm, and the collimator thickness of 7 cm and 8 cm, with geometric components of about 80% and 60%, are proposed as optimal collimators for energies of 364 keV and 511 keV, respectively.
کلیدواژهها English
