2008 年 43 巻 2 号 p. 122-130
A voxel phantom for a Japanese female adult was developed from CT data. This new phantom, Onago, has a slightly larger size than the Asian Reference Man, Female (ARMF). The organ doses and effective doses for external electrons were calculated with Onago in the energy range of 1MeV through 10GeV, and compared with those of a Japanese male voxel phantom Otoko and with those of a MIRD phantom. The organ doses show some typical tendencies which are common to all phantoms, and the absolute values are also similar. However, in some cases the absolute values of organ doses differ greatly among the phantoms: the maximum difference observed between the voxel phantoms and the MIRD-type phantom was a factor of fifty for the individual organ dose and a factor of two for the effective dose. This suggests the necessity of sophisticated phantoms and detailed investigation using the phantoms to find out the realistic reference organ doses and the fluctuations due to different factors for external electron exposures.