Development of adult Japanese voxel phantoms and their application to evaluation of radiation exposure doses

Sato, Kaoru   ; Takahashi, Fumiaki  ; Satoh, Daiki   ; Endo, Akira   

JAEA has developed two male and a female voxel phantoms using CT images of adult Japanese to study the effects of postures and body sizes on dose assessment. The three voxel phantoms consist of about 1 mm size voxels, and the shapes and masses of organs are more realistically reproduced. The two male voxel phantoms were constructed from the CT images of an identical person taken in supine and in upright. Therefore, it is possible to clarify the impact of posture on dose assessment by comparing directly organ doses of two phantoms. The present report describes (1) the construction and characteristics of the JAEA voxel phantoms, (2) the effects of postures on the organ doses by photon emitters, and (3) the effects of body sizes on organ doses by external photon exposures. The present study provides valuable information to understand the effects of posture and body size on dose assessment in adapting dose conversion coefficients calculated using the reference voxel phantoms by ICRP.