著者

山口 紘子 松本 光弘 太田 誠一 植田 崇彦 筒井 保裕

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.5, pp.602-607, 2012-05-20 (Released:2012-05-30)

参考文献数

8

被引用文献数

1

---

Introduction: We verified the setup error (SE) in two persons’ radiation therapist’s team, which consist of staff and new face. We performed the significance test for SE by the staff group and the new face group. Methods: One group consists of four staff therapists with at least 5 to 30 years of experience. The other group consists of new face radiation therapists that have 1 to 1.5 years of experience. Analyzed were 53 patients diagnosed with pelvic cancer (seven patients who underwent 3 dimensional conformal radiation therapy (3DCRT) and 46 patients who underwent intensity modulated radiation therapy (IMRT). Image verification was 1460 times. It was performed through setup verification by cone beam computed tomography (CBCT), and we measured SE of four directions (lateral, long, vertical, 3D). We performed the student’s t-test to get the difference of the average error between the staff group and the new face group. Results: The results of significance tests show that there is no difference between SE in the staff group and the new face group in radiotherapy.

著者

土橋 俊男 藤田 功 槇 利夫 北川 松雄 鈴木 健

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.54, no.4, pp.517-520, 1998-04-20 (Released:2017-06-29)

参考文献数

6

被引用文献数

4

著者

伊東 晶子

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.53, no.4, pp.485-489, 1997-04-20 (Released:2017-06-29)

参考文献数

15

被引用文献数

1

著者

土井 康寛 松山 倫延 池田 龍二 橋田 昌弘

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.72, no.7, pp.581-588, 2016 (Released:2016-07-20)

参考文献数

25

被引用文献数

1

---

This study was conducted to measure the recognition time of the test pattern and to investigate the effects of the maximum luminance in a medical-grade liquid-crystal display (LCD) on the recognition time. Landolt rings as signals of the test pattern were used with four random orientations, one on each of the eight gray-scale steps. Ten observers input the orientation of the gap on the Landolt rings using cursor keys on the keyboard. The recognition times were automatically measured from the display of the test pattern on the medical-grade LCD to the input of the orientation of the gap in the Landolt rings. The maximum luminance in this study was set to one of four values (100, 170, 250, and 400 cd/m2), for which the corresponding recognition times were measured. As a result, the average recognition times for each observer with maximum luminances of 100, 170, 250, and 400 cd/m2 were found to be 3.96 to 7.12 s, 3.72 to 6.35 s, 3.53 to 5.97 s, and 3.37 to 5.98 s, respectively. The results indicate that the observer’s recognition time is directly proportional to the luminance of the medical-grade LCD. Therefore, it is evident that the maximum luminance of the medical-grade LCD affects the test pattern recognition time.

著者

金山 秀和 梶谷 尊郁 宮原 善徳 北垣 一 竹下 治男

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.76, no.8, pp.870-872, 2020

著者

古屋 研 秋山 真治 中村 公二 佐野 芳知

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.835-840, 2012-07-20 (Released:2012-07-23)

参考文献数

20

被引用文献数

1

---

We measured the time-dependent change of computed tomography (CT) values for a blood sample in a syringe during 20 days expecting that the (average, maximum) CT values may be used to estimate the elapsed time after hemorrhage. The average CT value (CTave) rapidly increased for the first 50 min. The maximum CT value (CTmax) increased step by step to take the largest value (82.4 HU) one day later, and subsequently the CTmax decreased slowly to become 72.0 HU 20 days later. We conclude that the rapid increase of the CTave at the beginning is due to the fibrin generation, the increase of the CTmax is a result of the formation of the fibrin net, and the subsequent decrease of CTmax is caused by fibrinolysis. Tentative experimental formula for the time-dependent CTmax change at each increasing stage and decreasing stage are given to estimate the elapsed time after hemorrhage.

著者

中谷 香澄 福西 康修

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.71, no.5, pp.428-438, 2015 (Released:2015-05-20)

参考文献数

32

---

Computed tomographic angiography (CTA) has been used recently for the evaluation of intracerebral aneurysms, but it is difficult to use this technique to visualize aneurysms near the base of the skull because of the presence of bone. So, subtracted CTA has been used to separate vessels from bony structures. However, we see some misregistration when using subtraction method because of the patient moving, the disaccord of the X-ray tube orbit between the mask image and the live image, the expanding focus, and the bed bending. So, attentioning the difference of bone CT number in any tube voltages, we examined to make the image containing less misregistration by changing the tube voltage of mask image. Making a sham blood vessel, we examined the bone misregistration, the blood vessel volume, and the smoothness when changing the tube voltages of mask images. Comparing with 120 kV, as the tube voltage of the mask image was 80 kV, the bone misregistration decreased significantly, however the blood vessel volume decreased. As for the tube voltage of 100 kV, the bone misregistration decreased significantly, and the blood vessel volume and the smoothness were not significantly different so we could get coordinative image of 120 kV. When the tube voltage of the mask image becomes lower than that of the live image and the effective energy becomes different, the effect of misregistration is less. This method deals with changing the tube voltage only. So, it may be easy to make volume rendering (VR) image and this method may be used in every facility.

著者

高羽 順子 升屋 亮三 池田 俊貴 中垣 五月 斉藤 温己

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.48, no.6, 1992

著者

高羽 順子 升屋 亮三 斉藤 温己

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.47, no.10, 1991

著者

菅原 努 中村 実 林 太郎 深津 久治 小野 伸雄 田口 武雄

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.14, no.1, 1958

著者

深津 久治 小野 伸雄 佐藤 秀雄 渡辺 清 菅原 努 中村 実 田口 武雄

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.13, no.1, 1957

著者

菅原 努 中村 実 西田 三四郎 田口 武雄 深津 久治 小野 伸雄 高尾 義人

出版者

公益社団法人 日本放射線技術学会

雑誌

日本放射線技術学会雑誌 (ISSN:03694305)

巻号頁・発行日

vol.14, no.1, pp.81-82, 1958

著者

菅原 努 中村 実 楠瀬 誠 深津 久治 小野 伸雄

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.13, no.1, 1957

著者

粟井 一夫 川越 康充 菊地 透 諸澄 邦彦 山口 一郎 渡辺 浩 富樫 厚彦

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.57, no.4, pp.393-410, 2001

参考文献数

4

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平成12年12月26日,診療放射線の防護に関し,医療法施行規則の一部を改正する省令が,厚生省令第149号として関係告示(「廃棄物詰替施設,廃棄物貯蔵施設及び廃棄施設の位置,構造及び設備に係る技術上の基準の一部を改正する件:告示第396号」,「医療法施行規則第24条第6号の規定に基づき厚生労働大臣が定める放射性同位元素装備診療機器の一部を改正する件:告示第397号」および「放射線診療従事者等が被ばくする線量当量の測定方法並びに実効線量当量及び組織線量当量の算定方法の全部を改正する件:告示第398号」)とともに公布され,平成13年4月1日から施行されることとなった. ここに法令改正に関する理解を深めることを目的として新旧対比表を掲載し,主要部分に関する解説を加えた. なお,解説に関しては,学術交流委員会関係法令等検討小委員会委員および放射線防護分科会委員において意見交換を行い,法令改正に関する留意点の解説を諸澄邦彦,線量測定に関する概念について富樫厚彦がまとめた. 法令改正に関して会員各位の周知徹底を促すとともに,本報告が理解のための一助になれば幸いである.

著者

佐野 始也 松谷 英幸 近藤 武 関根 貴子 新井 雄大 森田 ひとみ 高瀬 真一

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.65, no.7, pp.903-912, 2009-07-20 (Released:2009-08-07)

参考文献数

12

被引用文献数

5 3

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Helical pitch (HP) usually has been decided automatically by the software (Heart Navi) included in the MDCT machine (Aquilion 64) depending on gantry rotation speed (r) and heart rate (HR). To reduce radiation dose, 255 consecutive patients with low HR (≤60 bpm) and without arrhythmia underwent cardiac MDCT using high HP. We had already reported that the relationship among r, HP, and the maximum data acquisition time interval (Tmax) does not create the data deficit in arrhythmia. It was represented as Tmax= (69.88/HP-0.64) r; (equation 1). From equation 1, HP=69.88 r/ (Tmax+0.64 r); (equation 2) was derived. We measured the maximum R-R interval (R-Rmax) on ECG before MDCT acquisition, and R-Rmax×1.1 was calculated as Tmax in consideration of R-Rmax prolongation during MDCT acquisition. The HP of high HP acquisition was calculated from equation 2. In HR≤50 bpm, Heart Navi determined r: 0.35 sec/rot and HP: 9.8, and in 51 bpm≤HR≤66 bpm, r: 0.35 sec/rot and HP: 11.2. HP of the high HP (16.4±1.2) was significantly (p<0.0001) higher than that of Heart Navi HP (10.9±0.6). The scanning time (6.5±0.6 sec) of high HP was significantly (p<0.0001) shorter than that of Heart Navi (9.0±0.8 sec), and the dose length product of high HP (675±185 mGy⋅cm) was significantly (p<0.0001) lower than that of Heart Navi (923±252 mGy⋅cm). The high HP could produce fine images in 251/255 patients. In conclusion, the high HP acquisition is useful for reduction of radiation dose and scanning time.

著者

池田 章人 吉川 宏起

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.75, no.2, pp.160-166, 2019 (Released:2019-02-20)

参考文献数

9

被引用文献数

1

---

Synthetic magnetic resonance imaging (MRI) can create different contrast weighted images by quantifying the T1, T2, and proton density values of the subjects from a single series of scan data. It has not been clarified how the signal to noise ratio (SNR) of the synthesized image varies depending on imaging parameters. We investigated the change of SNR in synthesized MR images by the experiment using self-made phantom. The SNR ratio of synthesized image by synthetic MRI showed the same tendency as the theoretical values due to parameter change in Ny, Nx, slice thickness, number of excitations. However, as for BW, the SNR ratio tended to be different from the theoretical values in some cases. In addition, it was suggested that the SNR of the composite image has relevance to the quantitative accuracy of the T1, T2, and proton density values. We thought that this is due to the image acquisition process by synthetic MRI.

著者

池田 龍二

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.76, no.5, pp.517-522, 2020 (Released:2020-05-20)

著者

齋藤 茂芳

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.75, no.8, pp.825-831, 2019 (Released:2019-08-20)

参考文献数

7

著者

高橋 寛治 加藤 京一 石田 秀樹 崔 昌五 中澤 靖夫

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.2, pp.137-144, 2011-02-25 (Released:2011-03-29)

参考文献数

6

被引用文献数

1

---

A study of a method of taking X-rays of the shoulder joint axis when the upper arm is fixed and cannot be rotated. When the shoulder joint has suffered damage, rotating the arm can be very painful, and obtaining accurate images of the axis is frequently difficult. For this reason, at this hospital, the Stockinette-Velpeau procedure is used on patients who cannot rotate their arms to have X-rays taken. In this procedure, the patient bends backwards at a 40-degree angle, and an X-ray of the shoulder joint axis is taken from directly below the joint. Using this method, even if the upper arm is hanging down, information regarding the direction of the axis can be obtained. However, maintaining this body position is difficult and requires assistance. The patient may also experience pain. For this reason, a new method was sought of X-raying the axis from a body position that is easier on the patient and by which diagnostic information on the axis direction can be obtained from patients who cannot rotate their upper arms. The result of seeking a new method was an X-ray that can be taken diagonally at a 25-degree angle relative to the shoulder joint socket. This X-ray method requires no rotation of the axis and provides the closest view of the axis. This new method suggests a way to X-ray the axis that is easy on patients even when the shoulder joint is damaged.

著者

藤村 一郎 市川 勝弘 寺川 彰一 原 孝則 三浦 洋平

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.6, pp.640-647, 2011-06-25 (Released:2011-07-01)

参考文献数

20

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For head computed tomography (CT), non-helical scanning has been recommended even in the widely used multi-slice CT (MSCT). Also, an acute stroke imaging standardization group has recommended the non-helical mode in Japan. However, no detailed comparison has been reported for current MSCT with more than 16 slices. In this study, we compared the non-helical and helical modes for head CT, focusing on temporal resolution and motion artifacts. The temporal resolution was evaluated by using temporal sensitivity profiles (TSPs) measured using a temporal impulse method. In both modes, the TSPs and temporal modulation transfer factors (MTFs) were measured for various pitch factors using 64-slice CT (Aquilion 64, Toshiba). Two motion phantoms were scanned to evaluate motion artifacts, and then quantitative analyses for motion artifacts and helical artifacts were performed by measuring multiple regions of interest (ROIs) in the phantom images. In addition, the rates of artifact occurrence for retrospective clinical cases were compared. The temporal resolution increased as the pitch factor was increased. Remarkable streak artifacts appeared in the non-helical images of the motion phantom, in spite of the equivalent effective temporal resolution. In clinical analysis, results consistent with the phantom studies were shown. These results indicated that the low pitch helical mode would be effective for emergency head CT with patient movement.