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

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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

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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

郡 倫一

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.77, no.10, pp.1203-1208, 2021 (Released:2021-10-20)

参考文献数

17

被引用文献数

1

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Background: The lesions caused by brainstem infarction are usually small. Therefore, it is often difficult to diagnose them using axial diffusion-weighted imaging (axial DWI). The purpose of this study was to evaluate the usefulness of thin-slice gapless coronal DWI in acute brainstem infarction diagnosis by difference of elapsed time from the onset of cerebral infarction. Methods: Axial DWI and coronal DWI were performed in 90 patients (mean age: 70.0±12.5 years) with acute brainstem infarction. Patients were classified into four groups according to the elapsed time after the onset of brainstem infarction: <3 h (group A), 3–10 h (group B), 10–30 h (group C), and ≥30 h (group D). We compared axial DWI and coronal DWI in terms of visual evaluation score, apparent diffusion coefficient (ADC) value, and contrast in the four groups. Results: The visual evaluation scores were significantly higher using coronal DWI in groups A, B, and C than in group D. The ADC values in groups C and D were significantly higher in coronal DWI. The contrast in groups C and D was significantly higher in coronal DWI. Conclusion: Coronal DWI is especially useful for acute brainstem infarction diagnosis within 30 hours of its onset.

著者

宇都宮 悟

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.77, no.10, pp.1245-1249, 2021 (Released:2021-10-20)

参考文献数

23

被引用文献数

2

著者

下 道國

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.7, pp.889-896, 2012-07-20 (Released:2012-07-23)

参考文献数

12

著者

上田 腎次 桜井 孝明 佐川 利幸 甲斐 忠商 松本 正行 八本 実紀男

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.33, no.5, 1978-01-01

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 8

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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

菊地 透

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.39, no.2, pp.203-204, 1983

著者

福士 政広 細田 正洋 杉野 雅人

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.9, pp.1237-1238, 2005-09-20

著者

稲垣 明里 平井 綾華 中島 義晴 弓井 孝佳 木村 憲明 木村 建次郎

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.79, no.1, pp.84-89, 2023-01-20 (Released:2023-01-20)

参考文献数

13

著者

杉浦 良樹 太田 益弘 平野 昌弘 石川 英男 浜口 正規 背戸 好廣 伊藤 龍彦 天野 智康 日下部 行宏 村上 逸則

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.45, no.2, 1989-02-01

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

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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

土居 雅広

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.5, pp.635-645, 2004-05-20

被引用文献数

3

著者

巻幡 弘 猪田 洋 青森 政司 崎谷 英樹 瀬尾 由美子 四ノ宮 恵 藤井 健 畦元 将吾

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.51, no.5, 1995

著者

田頭 豊 安部 圭亮 小野寺 崇 茅野 伸吾

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.79, no.12, pp.1375-1384, 2023 (Released:2023-12-20)

参考文献数

31

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Size-specific dose estimates(SSDE)は,computed tomography(CT)検査における体型の違いを考慮した線量指標であり,これまでvolume CT dose index(CTDIvol)では得られなかった任意の断面のおおよその吸収線量が評価できるようになった.Automatic exposure control(AEC)を使用した場合,CTDIvolは体軸方向に変調された値をとるが,検査終了後に表示される値はスキャン全体の平均値mean CTDIvolであり,局所のSSDE計算にどちらの値を使用するかにより値が変わることが予想できる.本研究では,SSDE算出にmean CTDIvolを用いるか,スライスごとの変調値を用いるかの違いが,局所の臓器線量評価へ与える影響について人体ファントムを用いて検証した.American Association of Physicists in Medicine (AAPM) Report No.220の手順に従いwater equivalent diameterを計算するプログラムを作成し比較検討した結果,mean CTDIvolを用いて計算されたSSDE(local-SSDEmean)は,肺野領域においてCT撮影による被ばく線量を評価するWebシステム(WAZA-ARIv2)で算出される臓器線量より18%–56%の過大評価となった.これに対しCTDIvolの変調値を用いて計算されるlocal-SSDEmodulatedは,臓器線量を10%–13%の相対誤差で評価できた.また体軸方向全域のlocal-SSDEを平均した値SSDEは,CTDIvolにいずれの方式を採用された場合でも両者の間に有意差を認めなかった.CT画像のdigital imaging and communications in medicine(DICOM)ヘッダータグ(0018, 9345)にmean CTDIvolが格納され,スライスごとに変調されたCTDIvolの値が得られない場合は,計算される局所のSSDEは誤差を多く含有し撮影部位の臓器線量を正しく反映しない.その場合には,スキャン全体のSSDEの平均値SSDEに臓器ごとの係数を乗じて局所の臓器線量を評価する手法は使用可能である.

著者

鈴木 千晶 藤崎 賢二 渥美 雄介 竹村 実紀 水野 孝一 永峯 岳樹 天野 智康 山本 英雄 高橋 護

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.73, no.4, pp.273-281, 2017 (Released:2017-04-20)

参考文献数

22

被引用文献数

2 3

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The purpose of this study is to measure the hemodynamics on the effect of Valsalva maneuver aiming at pulmonary thromboembolism (PTE) using 2-dimensional (2D) phase contrast imaging of magnetic resonance image (MRI), Philips Ingenia 3.0-tesla (T). The maximal inspiration reduced the blood flow rate in various degrees at all measurement positions, superior vena cava (SVC), inferior vena cava (IVC), pulmonary artery (PA), ascending aorta (AA), and descending aorta (DA). This result suggests that the contrast effect in the PA might become weak during general PA phase to give a substantial influence of Valsalva maneuver in the condition after maximum inspiration. A contrast-enhanced computed tomography (CT) examination aiming at detection for PTE should be scanned without an advance maximum inspiration.

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 5

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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

山村 憲一郎

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.77, no.7, pp.745-751, 2021 (Released:2021-07-20)

参考文献数

16

著者

上田 悦弘

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.76, no.10, pp.1066, 2020 (Released:2020-10-20)

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 8

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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.