An Investigation on Shielding Effect of Bismuth on Lung Ct Scan Using Monte Carlo Simulation

Abstract

Computed tomography (CT) related to computer-processed combination or X-ray images obtained from different angles to create patient’s cross-sectional body parts images. CT is mostly associated with high radiation dose to organs during the diagnostic process. To provide the probable effect of bismuth shielding on dose reduction to organs and investigation of applicability of Monte Carlo (MC) method. Monte Carlo (MC) method has been used for calculation of dose attenuation properties of bismuth. MCNPX (version 2.4.0) has been used during the calculations. In this study, validation of modeled MCNPX simulation geometry has been provided by calculating the mass attenuation coefficient values of lung and comparing with previous available studies in literature for lung. Our results agreed well with other results about mass attenuation coefficients of lung. By using the validated MC model, dose attenuation properties of bismuth have been investigated. Dose reduction rates of bismuth on lung have been compared with experimental studies. With bismuth shielding, absorbed dose amount in lung significantly reduced. It can be concluded from MC results that the bismuth shielding reduced lung dose significantly in x-ray CT examination of thorax region