研究者業績
基本情報
研究キーワード
2研究分野
1学歴
2-
- 2000年
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- 1975年
委員歴
3-
1998年 - 2005年
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1988年 - 1992年
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1981年 - 1983年
受賞
4-
2012年
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2002年
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1994年
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1989年
論文
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日本放射線技術学会雑誌 72(10) 1007-1014 2016年10月 査読有り<p>The diagnostic reference levels (DRLs) of the general X-ray radiography are defined by the absorbed dose of air at the entrance surface with backscattered radiation from a scattering medium. Generally, the entrance surface dose of the general X-ray radiography is calculated from measured air kerma of primary X-ray multiplied by a backscatter factor (BSF). However, the BSF data employed at present used water for scattering medium, and was calculated based on the water-absorbed dose by incident primary photons and backscattered photons from the scattering medium. In the calculation of air dose at the entrance surface defined in DRLs, there are no theoretical consistencies for using BSF based on water dose, and this may be a cause of calculation error. In this paper, we verified the difference in BSF by the difference in the scattering medium and by the difference in the objective dose by means of the Monte Carlo simulation. In this calculation, the scattering medium was set as water and the soft-tissue, and the objective dose was set as air dose, water dose, soft-tissue dose, and skin dose. The difference in BSF calculated by the respective combination was at most about 1.3% and was less than 1% in most cases. In conclusion, even if the entrance surface dose defined by DRLs of general X-ray radiography is calculated using BSF, which set both the scattering medium and the object substance of the absorbed dose as water, a so big error doesn't show.</p>
MISC
66-
Japanese Journal of Radiological Technology Special Issue 6 99-102 1987年
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Japanese Journal of Radiological Technology Special Issue 6 80-84 1987年
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日本放射線技術学会雑誌 42(4) 512-517 1986年In this report, we analyzed the field factors for the 10 MV X-ray irregular fields using a linear accelerator. We compared the field factors and TMRs at the same depth for two irregular fields of the same shape by means of (1) lead blocks and (2) installed multi-leaf collimator. There were no significant differences in either of the TMRs, and the TMRS were in good agreement with the TMR regarding their equivalent square field. On the other hand, there were significant differences in both the field factors, and the field factor for the lead block irregular fields were greater. From the results of this experiment, we are of the opinion that in routine dose calcultion, it is better to use field factors for the open fields in the case of the lead block irregular fields, and to use field factors for the equivalent square fields in the case of the irregular fields by means of multi-leaf collimator.
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Japanese Journal of Radiological Technology Special Issue 4 154-158 1985年
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日本放射線技術学会雑誌 40(7) 1065-1068 1984年In this report, we analyzed field factors, which are important parameter in dose calculations, for 60Co irregularly shaped fields. Measured field factors for irregular fields were different from the field factors for equivalent square fields obtained from the standard field factor curve measured on square fields defined by installed collimator. They were almost settled on field factors for their open fields. From the result of this experiment, we consider that in dose calculations for irregular fields it is better to use field factors not for equivalent square fields but for the open fields.
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Japanese Journal of Radiological Technology Special Issue 2 25-28 1983年
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加藤秀起, 石塚 晃 38(4) 436-440 1982年On the evaluation of radiation risk, the absorbed dose by specific organs, such as the skin or the gonads, is usually described, but it has been difficult to estimate the overall risk of patient exposed to radiation. The total energy imparted is one of the method often used for the relative estimation of total radiation risk. In this paper, its variability depending upon the condition of the X-ray exposure was evaluated and compared with the variability of skin exposure dose, the most commonly available data. Parallel variability of total energy imparted to skin radiation dose was detected as the tube voltage or the thickness of the phantom were changed or as the filter or the grid was added. Then, upon the change of FFD or field area, an independent or opposite variability was observed. Nevertheless, the skin dose-irradiated area product [rad. cm^2] registered similar variability to the total energy imparted upon changes of those mentioned factors. Consequently, it was demonstrated that the skin dose-irradiated area product [rad. cm^2], an easier to measure value, provided the relative estimation of the total radiation risk as well as the total energy imparted.
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日本放射線技術学会雑誌 37(6) 760-765 1981年The correction factor for the hollow out irradiation technique is usually calculated as a magnitude of dose reduction at the center of rotation with respect to primary radiation. This correction factor, which had taken account of scattered radiation, was calculated from the ratio of two average TARs with and without the hollow out absorber, and its scattered radiation component was distinguished from its primary radiation component to be analyzed. The magnitude of dose reduction rate with respect to the scattered radiation component was much the same to that with respect to the primary radiation component. Consequntly, the correction factor, which had taken account of scattered radiation, showed good agreement with the correction factor with respect to primary radiation only.
所属学協会
3Works(作品等)
3共同研究・競争的資金等の研究課題
4教育方法・教育実践に関する発表、講演等
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件名自作ソフトウェアによる放射線基礎科学の学習支援(第２回藤田保健衛生大学医療科学部相互研修ＦＤ)終了年月日2009/08概要放射線医療は、放射線と人体との相互作用による物理現象を利用したものである。放射線の多種多様な物理現象を理解するためには、膨大な物理データ、その取扱い方法の習得が必要となる。放射線学科学生の学習支援を目的に、放射線に関する種々の物理データおよびその取扱い、それらを用いた放射線基礎科学に関するコンピュータソフトウェアを作成した。その概要について報告した。