著者
伊場 昭三 筧 弘毅 有水 昇
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.27, no.1, pp.39-45, 1971-06-20

The gonad dose was evaluated upon forty-six patients with the hyperthyroid treated with the therapeutic dose of ^<131>I, 2 to 20mCi, These forty-six patients have been derived from all the out-patients, 15787 cases, visiting the Chiba University Hospital in recent twelve years. The gonadal exposure due to gamma rays of ^<131>I was directly measured by the pocket chambers placed close to the gonad of each patient, showing 0.35 to 0.4 rad per one mCi of ^<131>I the first 24 hours after the administration. Those of beta-rays, however, were approximately estimated at 0.3 rad per one mCi by using the specific activities of ^<131>I in the blood and the calculation. The fundamental experiment concerning the gonadal exposure was perfomed with a body-sized phantom containing ^<131>I solution, suggesting that ^<131>I excreted into the bladder had gave considerable contribution to the gonad dose.
著者
越田 吉郎 曽田 卓実 能登 公也 福田 篤志 松原 孝祐 中川 浩人 川端 千香子
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.61, no.7, pp.989-996, 2005-07-20
被引用文献数
1

Medical personnel involved in abdominal angiography are exposed not only to direct radiation but also scattered radiation from inspection tables, patients, image intensifiers, and the beam-limiting system (collimator), among others. Japanese standard JISZ4831 prescribes protective coats of at least 0.25mm lead equivalent, which is the uniform thickness of lead equivalent. The most commonly used protective coats are 0.25mm Pb, 0.35mm Pb, or 0.5mm Pb in thickness. The weight of a typical protective coat is about 3kg. While some coats weigh up to 6kg, wearing such heavy coats becomes physically burdensome as inspection time increases. The trade-off between physical burden and protection was considered by analyzing the X-ray intensity distribution and attenuation rate of scattered radiation in each position assumed by the medical staff. In the case of inspections performed at an x-ray tube voltage of 80kV, it may be possible to reduce the weight of the lead rubber apron by about 33%. Namely, the lead thickness can be reduced uniformly by 0.20mm Pb at 70cm and 0.05mm Pb at 100cm, when the shielding capability of a 0.25mm thick Pb layer is accepted as the standard at 40cm above the gonad position. The same range of permeated X-ray dose for the gonad position may be reduced as well. In the case of 110kV, when the lead thicknesses are 0.30mm Pb at 40cm and 70cm, and 0.10mm Pb at 100cm, it is possible to reduce the weight of the lead rubber apron by about 28%.
著者
八木 浩史 北村 怜子 猿渡 理恵 土居 奈津子 山根 英里子
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.59, no.6, pp.729-736, 2003-06-20
被引用文献数
5

The half-value layer (HVL) of an X-ray beam for film-screen mammography is considered an important parameter for image quality and patient dose. Thus, HVL must be measured in accordance with The Manual of Accuracy for Mammography printed by the Japanese Society of Radiological Technology. The manual prescribes exactly the geometry of measurement, chamber position of measurement in the field, selection of chamber, and so on. However, the measurement of HVL is difficult in the actual clinical setting. This study examined the results of failure to perform the measurement of HVL in accordance with the manual for measuring HVL in the clinical setting. The investigation indicated that serious problems do not arise when measuring HVL for routine quality control even if the chamber in the field is not always set according to the manual and if a chamber for radiotherapy or diagnosis is used that is not recommended for soft X-ray by the manual.
著者
熊谷 孝三 天内 廣 太田原 美郎 西村 健司 森田 立美
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.60, no.8, pp.1072-1077, 2004-08-20
被引用文献数
2

医療に向けられる社会の評価はかつてなく厳しいものになっており,その厳しさを示す具体的なものとして,医療事故をめぐる紛争,訴訟の増加が挙げられる.また日常の診療においては,患者への危害のみならず,物損や患者からの苦情など病院のイメージダウンを引き起こす要因が潜んでいる.これらも医療事故,紛争に直結するおそれがあり,病院の経済的損失につながる.したがって,自分の職場ではどのようなリスクが存在しているのか,また実際に起こっているかを調査し,その内容を把握することが重要である.これらのことを受け,本報ではアンケート調査を実施し,放射線業務において発生している患者からの苦情・質問についてモダリティ別に事例集としてまとめたので報告する.
著者
山口 功 石田 智一 木戸屋 栄次 東村 享治 鈴木 正行
出版者
公益社団法人日本放射線技術学会
雑誌
日本放射線技術學會雜誌 (ISSN:03694305)
巻号頁・発行日
vol.61, no.2, pp.260-267, 2005-02-20
被引用文献数
7

A strict determination of scan timing is needed for dynamic multi-phase scanning and 3D-CT angiography (3D-CTA) by multi-detector row CT (MDCT). In the present study, contrast media arrival time (T_<AR>) was measured in the abdominal aorta at the bifurcation of the celiac artery for confirmation of circulatory differences in patients. In addition, we analyzed the process of formation of the time-density curve (TDC) and examined factors that affect the time to peak aortic enhancement (T_<PA>). Mean T_<AR> was 15.57±3.75 s. TDCs were plotted for each duration of injection. The rising portions of TDCs were superimposed on one another. TDCs with longer injection durations were piled up upon one another. Rise angle was approximately constant in response to each flow rate. Rise time (T_R) showed a good correlation with injection duration (T_<ID>). T_R was 1.01T_<ID> (R^2=0.994) in the phantom study and 0.94T_<ID>-0.60 (R^2=0.988) in the clinical study. In conclusion, for the selection of optimal scan timing it is useful to determine T_R at a given point and to determine the time from T_<AR>.