Iran University of Medical Sciences
Computed tomography (CT) and CT angiography methods are used as a pre-test to evaluate patients with coronary artery disease. Due to the high dose of patients and staffs in this imaging method, dose reduction methods that deliver the lowest dose to patients while maintaining image quality are studied and researched. The purpose of this study was to evaluate the effectiveness of new phosphate ZnO-Bi2O3-P2O3 glasses to reduce the amount of received dose in coronary angiography.
In this study, Monte Carlo software code MCNPX6 was used. Single energy photon source from 100 to 700 keV with distances of 50 keV was defined which is the energy used in all diagnostic procedure. Then Bi2O3-particle dimensions of 50 nm and 50 micrometers were considered in the simulation. The ZnO- Bi2O3-P2O3 glasses were simulated at six different concentrations and percentages. Then the linear and mass attenuation coefficients of each of these samples were calculated.
The results showed that phosphate glass filled with Bi2O3 nanoparticles were more efficient than conventional phosphate glass or filled with Bi2O3 micro-particles. Also at low photon energies both shields had better radio-protection performance. Also due to the filler concentration and photons energy, a dose reduction of 16-27% was found.
The results showed that the use of bismuth oxide nanoparticles as filler in glasses, leads to an acceptable decrease in organ received dose.