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Yoshitomi, Hiroshi; Nishino, Sho; Tanimura, Yoshihiko; Takahashi, Masa
Radiation Measurements, 133, p.106279_1 - 106279_6, 2020/04
Times Cited Count：5 Percentile：53.85(Nuclear Science & Technology)Uncertainty of the body size on the counting efficiency of a newly developed thyroid monitor was estimated by Monte Carlo simulations using several voxel phantoms. Overlying tissue thickness was a major impact factor on the counting efficiency. As a result, uncertainty related to the body size of the monitored subject was found to be 25%.
Sato, Kaoru; Takahashi, Fumiaki
Hoken Butsuri, 52(4), p.247 - 258, 2017/12
Organ doses for dose assessment in radiation protection are derived from ICRP reference phantoms (Male:RCP-AM, Female:RCP-AF) with standard Caucasian physiques. In adult, Japanese are smaller than Caucasian. To study impact of differences in physiques between Caucasian and Japanese on organ doses, we previously constructed Japanese phantoms (Male:JM-103, Female:JF-103) with average adult Japanese physiques. In addition, adult Japanese physiques have also wide distribution. Thus, we newly modeled DJM (Male) and DJF (Female) with 8 physiques by changing the perimeters of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV, it was found that doses of breast, colon, lung, stomach, gonad, urinary bladder, esophagus, liver and thyroid in DJM and DJF with physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10%.
Sato, Kaoru; Takahashi, Fumiaki; Endo, Akira; Ono, Koji*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Ban, Nobuhiko*; Kai, Michiaki*
RIST News, (58), p.25 - 32, 2015/01
The Japan Atomic Energy Agency (JAEA) are now developing WAZA-ARI for improvement of management of exposure doses due to CT examination under the joint research with the Oita University of Nursing and Health Sciences. The trial version of WAZA-ARI has been released on 21 December 2012. In trial version, users can perform dose assessment by using organ dose database based on the average adult Japanese male (JM-103) and female (JF-103) voxel phantoms and a 4 years old female voxel phantom (UFF4). The homepage of WAZA-ARI has been accessed over 1000 times per month and 28421 times by the end of September 2014. We are developing WAZA-ARI version 2 as the extension version of dose calculation functions of WAZA-ARI. WAZA-ARI version 2 will be released by the end of March 2015. In WAZA-ARI version 2. Users can upload dose calculation results to WAZA-ARI version 2 server, and utilize improvement of the dose management of patients and the optimization of CT scan conditions.
Sato, Kaoru; Noguchi, Hiroshi; Emoto, Yutaka*; Koga, Sukehiko*; Saito, Kimiaki
Radiation Protection Dosimetry, 123(3), p.337 - 344, 2007/02
Times Cited Count：39 Percentile：91.43(Environmental Sciences)A Japanese adult male voxel (volume pixel) phantom (hereinafter referred to as the JM phantom) was constructed on the basis of CT images of a healthy Japanese adult male volunteer. Body characteristics of the JM phantom were compared with those of a voxelized MIRD5 type phantom and a Japanese adult male voxel phantom which was previously developed. The voxel size of the JM phantom is 0.98
0.981 mm
. The shapes of organs of the JM phantom, even for small or complicated organs, such as thyroid and stomach, are more realistically reproduced as compared with the previous Japanese voxel phantom (voxel size: 0.980.9810 mm). Photon self-absorbed fractions for brain, kidneys, spleen, pancreas, thyroid and urinary bladder wall of JM were evaluated and were compared with those of the other phantoms. In consequence, it was suggested that the mass, shape and thickness of organs are important factors for the determination of self-absorbed fractions.
Yamaguchi, Yasuhiro
Radioisotopes, 47(11), p.844 - 854, 1998/11
no abstracts in English
Sato, Kaoru; Takahashi, Fumiaki; Endo, Akira; Ono, Koji*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Yoshitake, Takayasu*; Ban, Nobuhiko*; Kai, Michiaki*
no journal, ,
The Japan Atomic Energy Agency are now developing WAZA-ARI for improvement of management of exposure doses due to CT examination under the joint research with the Oita University of Nursing and Health Sciences. The trial version of WAZA-ARI has been released to the public via the home page of the National Institute of Radiological Sciences for test operation. In trial version, users can perform dose assessment against average adult Japanese by using organ dose database based on the JM-103 (male) and JF-103 (female) phantoms with average body sizes of adult Japanese. To expand functions of WAZA-ARI to enables users to perform against adult patients with other body sizes, we developed the adult Japanese phantoms with small, large and extra-large body sizes by modifying JM-103 and JF-103. By dose analysis based on these phantoms, it was concluded that organ doses per current are strongly dependent on body sizes.
Manabe, Kentaro; Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Effective doses based on ICRP 2007 Recommendations are evaluated using sex averaged equivalent doses. On the other hand, it is required that the situations of exposure are considered as possible in estimating doses for radiation accidents and medical interventions. Then, there are sex specific organs and differences between males and females in masses and positions in bodies of organs (physical characteristics). It is useful to reveal an impact of these differences in physical characteristics on dose estimation. In this study, a comparison was made with organ doses between male and female using photon and electron SAFs based on Japanese adult male and female phantoms (male: JM-103, female: JF-103), which have average physiques and organ masses of adult Japanese, and the recent nuclear decay data and biokinetic models of ICRP. As a result, it is revealed that several tens of percent of discrepancies in organ doses between male and female was caused by sex differences in physical characteristics.
Sato, Kaoru; Takahashi, Fumiaki
no journal, ,
Organ doses, which are basis of dose assessment in radiation protection, are derived from ICRP reference phantoms (Male: RCP-AM, Female: RCP-AF) with body physiques of standard Caucasian. In adult, Japanese body physiques are smaller than those of Caucasian. To study impact of application of organ doses of RCP-AM and RCP-AF to dose assessment of adult Japanese, we constructed Japanese male (JM-103) and female (JF-103) phantoms with body physiques of average adult Japanese. In addition, body physiques of adult Japanese have also wide distribution. Therefore, we newly constructed DJM (Male) and DJF (Female) with 8 body physiques by changing bust, chest, waist and hip of JM-103 and JF-103. Organ doses due to external photon irradiation of DJM and DJF were calculated, and were compared with those of RCP-AM and RCP-AF. In ISO geometry at 0.3 MeV and ROT geometry at 0.6 MeV, it was found that colon doses of DJM and DJF with body physiques, which are applicable to most adult Japanese, agreed with those of RCP-AM and RCP-AF within 10 %.
Kinase, Sakae
no journal, ,
no abstracts in English
Endo, Akira
no journal, ,
Individual doses for the Life Span Study (LSS) of atomic bomb survivors have been estimated using the Dosimetry System 2002 (DS02). DS02 estimates individual doses using organ dose database calculated by three age-specific mathematical phantoms (infant, child and adult) developed in 1980s, distance from the hypocenter, and shielding conditions. Nowadays more anatomically realistic phantoms, voxel type and polygon mesh type, have been developed, and the use of these phantoms will improve assessment of organ doses of the atomic bomb survivors. The study compares organ doses calculated using mathematical and voxel phantoms of adult and quantifies dosimetric impacts of the use of the new phantoms on the assessment of organ doses.
Sato, Kaoru; Takahashi, Fumiaki; Koba, Yusuke*; Ono, Koji*; Yoshitake, Takayasu*; Hasegawa, Takayuki*; Katsunuma, Yasushi*; Kasahara, Tetsuji*; Okuda, Yasuo*; Nakada, Yoshihiro*; et al.
no journal, ,
WAZA-ARIv2 is developed as the web-based open system for CT dose calculator under joint research of JAEA, NIRS (now, QST) and Oita University of Nursing and Health Sciences. WAZA-ARIv2 can provide organ doses under consideration of the body physiques (BMI = 18, 22, 28, 37) of patients with average height of adult Japanese by using voxel phantoms developed by JAEA. In this study, we analyzed the relationship between variations of organ doses and body indices. It was found that effects of weight variations on organ doses were larger than those of height variations. Generally, thickness of the subcutaneous soft tissues is easily changed by variations of weight rather than those of height. This fact may cause the differences in variations of organ doses between weight and height.
