Photon Interaction Properties of Different Bones from Human Body Using MCNPX, WinXCom, XMuDat, and Auto-Zeff Programs

Abstract

Abstract The human body consists of various bones with different elemental compositions and densities. The mass attenuation coefficients (μm), effective atomic and electronic cross sections (σa and σe), effective atomic numbers and electron densities (Zeff and Neff), and computed tomography (CT) numbers of the human body’s various bones have been determined for the main gamma rays of 67gallium, 153samarium, 99mtechnetium, 201thallium, 131iodine radionuclides and gamma rays from positron annihilation. To calculate these parameters, MCNPX code, WinXCom, and XMuDat computer programs and also the Auto-Zeff software and interpolation method have been used. The results of the MCNPX code were in good agreement with the WinXCom and XMuDat programs with differences of ≤4.42 %. It was found that the σa, σe, Zeff, and CT number parameters decrease as photon energy increases and the density of bone samples decreases. The μm and Neff values decrease with the increase in photon energy based on the results. Furthermore, they are approximately independent of the bone sample density. Of all the bone types, the σa, σe, Zeff, and CT number values of cortical bone are the greatest ones, while those of spongiosa are the lowest. Observed good agreement reveals that the chosen Monte Carlo code and computer programs could be useful to calculate the photon interaction characteristics of different bone types.