Development of Chinese adult male mathematical phantom and external radiation dose calculations

A new mathematical phantom, the Chinese MIRD (CMIRD), was developed based on the high-resolution data set of Visible Chinese Human (VCH). The position and size of organs were obtained from the voxel-based VCH model, using the minimal 3D bounding box method. According to the equations of the ORNL adult phantom, the original CMIRD based on that anatomic information was constructed and the method of proportional deformation was adopted in order to compare the external radiation dose of different height models for different radiation directions and particles with MCNPX. The stimulation results obtained from CMIRD present comparable to those published dose values. The analysis of the discrepancies indicates that the shape, location and mass of organs have great influence on radiation dose especially at low energies. The comparison of the effective doses for models with different size shows that the size of the model is important, and the smaller models receive larger doses. Also, the deeper organs present more sensitive to the organ size than the shallower ones. In addition, the mathematical model is superior in speed of the radiation dose calculation, which requires simpler definition and less memory space.