JaLCDOI 10.18926/11931
Title Alternative Statistics and analysis on the troubles of linear accelarator.
FullText URL 005_099_103.pdf
Author Nakagiri, Yoshitada| Mikami, Yasutaka| Azuma, Yoshiharu| Sibuya, Koichi| Goto, Sachiko| Inamura, Keiji| Tahara, Seiji| Uno, Hirofumi| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract 放射線治療の成否は厳密に設定されたTarget Volumeに如何に正確な線量を照射するかによって決まる。治療術式の過程において、最も大きな誤差を生む要因は照射機器である。誤差の少ない治療を目指す第一歩は機器を正確に作動させることであり、日常からの保守点検および整備が必要である。今回、岡山大学附属病院で1976年から1991年までに使用されたリニアックについて、その故障状況を集計し、部位別故障件数、管球の寿命、稼動率などを分析検討した。その結果、故障件数では設置され稼動を始めた1976年、装置の老朽化が進んだ1990、1991年に多かった。部位別集計では加速部に圧倒的に多く、次いで照射口、高圧部の順であった。稼動率は設置年および1987年を除いてはいずれも96%以上とよい結果であった。この結果は全国に稼動している同型の装置の保守点検に役立つものと考える。
Abstract Alternative The Accuracy of radiation dose exposed the rigidly selected target volume is one of significant factors that have an influence upon the efficiency of treatment in the radiotherapy techniques. Therefore, it is necessary to daily maintain and check irradiation equipment for the radiotherapy. For the radiotherapy, the electron linear accelerator, Toshiba LMR-15A, had worked from 1976 to 1991 in Okayama University Hospital. On this study, all records regarding the operating condition were analyzed concerning parts of trouble, life of a tube and operating efficiency for these sixteen years. In a high frequency of trouble, an accelerating structure ranked first, followed by a collimator and a high voltage generator. The operating efficiency was 95% or greater. This report should be helpful to maintain and check a same model in other hosptals.
Keywords 放射線治療 (radiotherapy) 直線加速器 (linear accelarator) 故障 (troubles of radiation system)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1995-01-31
Volume volume5
Start Page 99
End Page 103
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313722
JaLCDOI 10.18926/11900
Title Alternative Faculties' ideas to the school syllabus
FullText URL 005_001_008.pdf
Author Ohta, Takeo| Shimoishi, Yasuaki| Azuma, Yoshiharu| Endo, Hiroshi| Okazaki, Yuka|
Abstract シラバスは、その内容も含めて、まだ教官にも、学生にもなじみのない言葉である。著者らは、1994年、初めてのシラバス(講義要覧)を刊行した。このシラバスの中では、1人もしくは数人の教官によって、1教科・1学期分の講義の概要が各1ページの中に記載され、その枠組みは、基本的事項以外に、抗議の目標、授業計画、授業計画、教科書、参考書、授業の進め方、評価の方法、教官のメッセージから成るものであった。このシラバス作成に参加した専任教官45人及び非常勤教官107人、計153人に対し、調査表によってシラバス作成に関する意見を求めた結果、117人(77.0%)の教官が解答を寄せた。その結果は次のようなものであった。1.今回の作成計画以前にシラバスについて認識があった者は44.5%であった。しかし、シラバスの今後の発行に関しては94.9%の者が賛成であった。今回の枠組みについてはほとんどの者が肯定的であった。2.学生による授業評価については、約半数(52.7%)が賛成であるが、時期尚早とする者が41.8%いた。
Abstract Alternative The term 'syllabus' and its concept are not familiar to university faculty members and students in Japan. Authors who belonged to School of Health Sciences Okayama University, published the first syllabus in 1994. In this syllabus, an outline of each course for a semester was shown by one or a few faculty members. The framework consisted of the mark of the subject, schedule, textbook, reference book, how to teach, how to grade and message to students, besides basic information. Forty-five full-time faculty members and 107 part-time faculty members were asked about their ideas for the syllabus through a questionnaire survey by mail and 119 faculty members (78.3%) responded to it. Only fifty-three faculty members (44.5%) had known the term 'syllabus' before the time when they started to talk about it or were asked to write it. But after their presenting syllabi, 104 faculty members (87.4%) agreeded to continue publishing and they were affirmative to framework as it was proposed this time. As for evaluation of subject by students, about half of faculties (52.7%) agreeded and 51.8% of them replied that were not mature enough for it yet.
Keywords シラバス (syllabus) 授業要覧 授業概要 教官の意見 (faculties' idea) evaluation by student
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1995-01-31
Volume volume5
Start Page 1
End Page 8
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313605
JaLCDOI 10.18926/11886
Title Alternative Analysis of Tempormandibular Joint by Image Processing -Discrimination of Condylar Position-
FullText URL 004_075_082.pdf
Author Azuma, Yoshiharu| Gotou, Sachiko| Nakagiri, Yoshitada| Nakamura, Nobue| Shibuya, Kouichi| Yamada, Toshiharu| Sugita, Katsuhiko| Mikami, Yasutaka| Hiraki, Yoshio|
Abstract Tomography is clinically useful in the diagnosis of the temporomandibular joint (TMJ) syndrome. The TMJ is formed by the condyle and the glenoid fossa, and there exists TMJ space between them. Image processing was employed in the present study, and the reference points of the condyle and the glenoid fossa were determined from the tomogram. Subsequently, the TMJ space was measured automatically in the image analysis. The TMJs of 98 patients were examined practically and the characteristics of each result were studied. There is a possibility of discriminating an abnormal condylar position from a normal one by making use of the TMJ space and the distance between two reference points.
Keywords Condylar Position Temporomandibular Joint Space Image Processing Tomogram Discrimination
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1994-01-31
Volume volume4
Start Page 75
End Page 82
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313405
JaLCDOI 10.18926/11878
Title Alternative Dosimetry in Radiography
FullText URL 004_069_073.pdf
Author Nakagiri, Yoshitada| Goto, Sachiko| Mikami, Yasutaka| Azuma, Yoshiharu| Sibuya, Koichi| Inamura, Keiji| Tahara, Seiji| Uno, Hirohumi| Takata, Yoshiaki| Tandani, Nobuyoshi| Yamada, Toshiharu| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract Utilization of radiation in medical treatment is increasing more and more ; consequently, It becomes more important to estimate exposure dose correctly. Altough there are many reports about exposue dose for patients, most of them merely describe the results of the measurements by parts of the body. Exposure dose differs with equipment, instruments, screen-firm system, contition of radiography, and so on. This paper describes the relation between skin dose and contitions of radiography, and also shows the result of measurement of "TPR" which needs to know the absorbed dose of each organ.
Keywords 線量測定 低エネルギー 被曝
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1994-01-31
Volume volume4
Start Page 69
End Page 73
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313669
JaLCDOI 10.18926/11874
Title Alternative Estimation of balium preparations with high density and low viscosity
FullText URL 004_057_060.pdf
Author Shibuya, Koichi| Kobashi, Takao| Ogasawara, Mitsuo| Tandani, Nobuyoshi| Nakagiri, Yoshitada| Azuma, Yoshiharu| Sugita, Katsuhiko|
Abstract In this paper we compared the balium preparations having high density and low viscosity (BP-HDLV) with those currently in use. We adopted the stomaches of pigs and the new phantom manufactured by ourselves. We especialy noted the quality of the contrast. The results indicate that BP-HDLV do not always make high contrast. The contrast is related to fluidity besides density. The fluidity of BP-HDLV should be improved. In adition, it costs much to increase content of balium. Therefore, we can not find out positive significance to use these BP-HDLV.
Keywords contrast medium balium density viscosity fluidity
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1994-01-31
Volume volume4
Start Page 57
End Page 60
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313918
JaLCDOI 10.18926/11820
Title Alternative Photon background caused by the reduction of the electron beam energy - Materials of scattering foil -
FullText URL 003_013_018.pdf
Author Nakagiri, Yoshitada| Mimura, Seiiti| Inamura, Keiji| Tahara, Seiji| Miyake, Hideaki| Azuma, Yoshiharu| Egusa, Tomomi| Mikami, Yasutaka| Hiraki, Yoshio| Yamada, Toshiharu| Sugita, Katsuhiko|
Abstract The total skin electron beam therapy has been one of the clinical treatment for peripherally T-cell lymphoma; Mycosis fungoides, adult T-cell lymphoma, and so on. The crucial points in this treatment are not only having an optimum energy level of electron beam for a target volume (a tissue) but also keeping the photon back ground low. It is not easy to regulate those points by the control panel, however, for the equipment that is conventinally used for electron beam, theoretically, is to exchange lead (Pb), which is ordinarily used, to a low atomic number material as a scattering foil. We examined several different kinds and / or various thickness as a scattering foil material that can make the electron beam lower without an increase of the contaminant as X-ray. We hereby reported the results, and strongly suggested the following two materials in use; acrylic plate, carbon board, and so on, which are easily available and worked, would be practically useful for the total skin electron beam therapy.
Keywords 電子線エネルギー X線混入率 電子線全身照射法 スキャタリングホイル
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1993-01-31
Volume volume3
Start Page 13
End Page 18
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313375
JaLCDOI 10.18926/11808
Title Alternative RESOLUTION PROPERTIES OF CRT MONITORS
FullText URL 002_081_088.pdf
Author Takeuchi, Tomoyuki| Yoshida, Akira| Azuma, Yoshiharu| Sugita, Katsuhiko| Nakamura, Nobue| Kishi, Kanji| Hiraki, Yoshio|
Abstract We have developed a new technique for measuring the modulation transfer function (MTF) of a cathode ray tube (CRT) monitor. The "nominal" MTF was measured by displaying a line image of a width of one pixel on the CRT monitor using the pattern generator. We also measured the effective pixel width. In order to obtain the "actual" MTF, the nominal MTF was divided by the sinc function which is the Fourier transform of the effective pixel width. The results indicate that the corrected MTF converges to the constant value as the effective pixel width is narrower. Thus, the actual MTFs were determined and compared in the horizontal direction for two CRT monitors.
Keywords CRT Monitor Resolution Effective Pixel Width Modulation Transfer Function (MTF)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1992-02-05
Volume volume2
Start Page 81
End Page 88
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313719
JaLCDOI 10.18926/11805
Title Alternative Dose Distributions at Standard Diagnostic X-Ray Energy
FullText URL 002_063_071.pdf
Author Miyake, Hideaki| Inamura, Keiji| Nakagiri, Yoshitada| Kadohisa, Shigefumi| Mikami, Yasutaka| Azuma, Yoshiharu| Yamada, Toshiharu| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract Exposure dose has been indicated by surface dose or transit dose, but they could not indicate dose distributions inside the body. Modulex as the radiation therapy planning system was used for dose distributions at standard diagnostic X-ray energy. X-ray is low energy X-ray at standard diagnostic radiography, so alterations of the energy and the scattering dose distribution by absorbers are quite different from those at high energy X-rays. Mix-DP was put to the homogeneous tissue use, then Bone equivalent phantom or Lung equivalent phanton was put to the inhomogeneous tissue use. Density correction factors for inhomogeneous phantoms were gotten by the calculation of the water equivalent thickness. In Bone the inhomogeneous correction depended strongly on the bone thickness. In Lung it was in need of one density correction factor and the scattering correction method for the decrease of the back scattering. The calculated dose distributions by Modulex agreed with measured data when each correction was carried out, and it was indicated that those data apply to inclinical situations.
Keywords Exposure Dose Dose Distribution Radiation Therapy Planning System Density Correction Scattering Correction
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1992-02-05
Volume volume2
Start Page 63
End Page 71
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313328
JaLCDOI 10.18926/11755
Title Alternative New Stepwedge for Bootstrap Sensitometry in Medical Radiography
FullText URL 001_019_027.pdf
Author Yoshida, Akira| Kobashi, Toshimi| Ohkawa, Yoshihiro| Mikami, Yasutaka| Hiraki, Yoshio| Azuma, Yoshiharu| Yamada, Toshiharu| Sugita, Katsuhiko|
Abstract A new stepwedge has been developed for bootstrap sensitometry, which is used for determining the characteristic curve of radiographic screen/film systems. Since each step of the stepwedge is separated by the lead septum, flare generated under one step will not penetrate the region of another step. The metal of the stepwedge can be changed with various materials. Characteristic curves obtained with new stepwedge bootstrap (NSB) and conventional stepwedge bootstrap (CSB) techniques were compared with those obtained for screen/film systems with inverse sqare sensitometry. The inverse square method was used as the reference standard for accuracy. The NSB method provided characteristic curves that agreed well with those obtained using the inverse square method. The slope of the curve in the CSB method was lower than that in the inverse square or NBS method, because of scatter radiation. The shape of the characteristic curve from the NSB method did not vary with the materials of step metals (aluminum and copper). The cumulative error involved when using the bootstrap method is also discussed.
Keywords Stepwedge Bootstrap Characteristic curves Sensitometry Radiographic screen/film systems
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1991-03-25
Volume volume1
Start Page 19
End Page 27
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313394