著者
安斎 育郎
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.36, no.2, pp.209-225, 1980
被引用文献数
2

Explanations were given as to the characteristic of the MIRD Committtee method for estimating the internal radiation doses due to the radioisotope administration, with special emphasis on the comparison with the method described in the ICRP Publication 2. The method evolved in the MIRD pamphlets have actually developed the accuracy of the calculation of the absorbed energy per disintegration of the radionuclide deposited in various organs, and it became more important to evaluate exactly the cumulated activity A^^〜 in the internal organs concerned. Some examples were selected for explaining how the MIRD pamphlets could practically be used, in which the author emphasized that the precise evaluation of the retention function, especially of its long-term components, was quite important for improving the accuracy of the dose assessment. The method for obtaining the "S" value for the organ mass that is different from that of the MIRD phantom was described. The author finally discussed the problem of estimating the mass of each internal organ out of the anthropometrical parameters such as body height and body weight.
著者
寺下 貴美
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.67, no.4, pp.413-417, 2011

研究方法論においてデータの性質から、数値で表されるデータを量的データ性質や特徴など数値で表せないデータを質的データという2つに分類される。 本稿では、質的データを扱う研究手法である質的研究手法に焦点を絞り、質的研究手法において理解すべき基本的項目を網羅的に紹介する。
著者
西浦 博
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.66, no.11, pp.1485-1491, 2010-11-22 (Released:2010-11-19)
参考文献数
19
被引用文献数
3 5

Understanding inter-observer variability in clinical diagnosis is crucial for reliability studies. As the statistical measurements of reliability, the kappa statistic and its extensions have been widely adopted in medical research, but it has been discussed that kappa is vulnerable to prevalence and presence of bias. As an alternative robust statistic, AC1 has attracted recent statistical attentions. This article describes fundamental ideas and quantitative features of AC1. The reliability of infrared thermoscanner as an application in detecting febrile patients of pandemic influenza is discussed by means of Monte Carlo simulation. AC1 adjusts chance agreement more appropriately than kappa and is regarded as a more useful measurement for assessing inter-observer agreement, especially when prevalence is small.
著者
小沼 洋治 林 美智子 林 裕晃 西原 貞光
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.68, no.3, pp.277-282, 2012-03-20 (Released:2012-03-24)
参考文献数
12
被引用文献数
4

We tried to remove contamination of radioisotope (RI) for an X-ray detector (photostimulable phosphor plate; IP) and verified that our procedure suggested by Nishihara et al. was effective for decontamination. The procedure was as follows. First, the IP was kept for approximately twelve hours, and then it was processed [image (A)] as well as a clinical processing mode. Second, using a wet-type chemical wiper, we scavenged the IP to remove the adhered RI on its surface. Then, once again, the IP was kept for approximately fifteen hours and processed [image (B)] in order to check an effect of decontamination. Finally, the two images of (A) and (B) were analyzed using ImageJ, which can be downloaded as a free software, and a percentage of removal was calculated. The procedure was applied to two IPs using the FCR 5501 plus. In the present case, the percentage of removal was approximately 96%. The removed radioisotopes in the chemical wipers were analyzed by Ge detector. Then, 134Cs and 137Cs were found with activities of 2.9 4.3 Bq and 3.5 5.2 Bq, respectively. For three months after that, we cannot see black spots on the IPs owing to the contamination of the RI and there are no defects caused by decontamination using a wet-type chemical wiper.
著者
池口 裕昭 庄内 孝春 巳上 綾 矢澤 夏佳 高橋 正 山田 幸二
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.69, no.1, pp.71-79, 2013-01-20 (Released:2013-01-25)
参考文献数
11
被引用文献数
3 4

Purpose: Homogeneity of static magnetic field (B0) is unstable for head and neck magnetic resonance (MR) examination; consequently, chemical shift selective fat suppression becomes inhomogeneous. There is a commercially available additional pad to attenuate the B0 inhomogeneity, but it is expensive. It has been reported that uncooked rice can be used as a material in the pad, but it has hygienic and weight problems. We searched for a material which can replace the uncooked rice, and evaluated its performance. Method: After filling various materials into the cylindrical phantom, each material was evaluated by image distortion of gradient filed echo and spin echo single-shot echo planar images. A prototype additional pad was made with a material which showed less image distortion in the phantom experiment and is easily available in clinical examination. For comparison, an uncooked rice pad with the same volume was also prepared. Fat suppressed head and neck magnetic resonance imaging (MRI) of normal volunteers were visually compared when the three additional pads, including the commercial product, were used or not. Result: The polystyrene ball bullet (BB bullet) was adopted as a material for the additional pad. The improvement of the fat suppression in the head and neck MRI was almost the same between the three additional pads. BB bullet pad was the lightest. Conclusion: BB bullet can be used as a material of additional pad attenuating the B0 inhomogeneity instead of uncooked rice.
著者
宮島 隆一 藤淵 俊王 宮地 優介 立石 哲士 宇野 善徳 天川 一利 大浦 弘樹 折田 信一
出版者
公益社団法人 日本放射線技術学会
雑誌
日本放射線技術学会雑誌 (ISSN:03694305)
巻号頁・発行日
vol.74, no.4, pp.326-334, 2018 (Released:2018-04-20)
参考文献数
16
被引用文献数
3 7

Medical staffs like radiological technologists, doctors, and nurses are at an increased risk of exposure to radiation while assisting the patient in a position or monitor contrast medium injection during computed tomography (CT). However, methods to protect medical staff from radiation exposure and protocols for using radiological protection equipment have not been standardized and differ among hospitals. In this study, the distribution of scattered X-rays in a CT room was measured by placing electronic personal dosimeters in locations where medical staff stands beside the CT scanner gantry while assisting the patient and the exposure dose was measured. Moreover, we evaluated non-uniform exposure and revealed effective techniques to reduce the exposure dose to medical staff during CT. The dose of the scattered X-rays was the lowest at the gantry and at the examination table during both head and abdominal CT. The dose was the highest at the trunk of the upper body of the operator corresponding to a height of 130 cm during head CT and at the head corresponding to a height of 150 cm during abdominal CT. The maximum dose to the crystalline lens was approximately 600 μSv during head CT. We found that the use of volumetric CT scanning and X-ray protective goggles, and face direction toward the gantry reduced the exposure dose, particularly to the crystalline lens, for which lower equivalent dose during CT scan has been recently recommended in the International Commission on Radiological Protection Publication 118.
著者
大塚 益比古
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.56, no.10, pp.1212-1213, 2000-10-20
被引用文献数
2 1
著者
森下 雄太 宮地 利明 上田 丞政 清水 満 濱口 隆史 藤原 康博 林 弘之
出版者
日本放射線技術学会 = Japanese Society of Radiological Technology
雑誌
日本放射線技術學會雜誌 = RADIOLOGICAL TECHNOLOGY (ISSN:03694305)
巻号頁・発行日
vol.64, no.5, pp.587-590, 2008-05-20
参考文献数
13
被引用文献数
1

The purpose of our study was to assess the mechanical effect on tattoo seals and eye makeup caused by a spatial magnetic gradient in the magnetic resonance imaging (MRI) system. Seven kinds of tattoo seals and three kinds of eye makeup, i.e., mascara, eye shadow, and eyeliner were used. On a 3.0-Tesla MRI, we determined these deflection angles according to a method established by the American Society for Testing and Materials (ASTM) at the position that produced the greatest magnetically induced deflection. Eighty-five percent of the tattoo seals showed deflection angles greater than 45 degrees of the ASTM guidelines, and the mascara and eye shadow showed over 40 degrees. This was because these contained ferromagnetic pigments such as an iron oxide, but those translational forces were very small owing to slight mass. However, it is desirable that these should be removed before MRI examination to prevent secondary problems.