JaLCDOI 10.18926/11690
Title Alternative A study of x-rays protection in a hip-joint radiography examination
FullText URL 011_2_059_064.pdf
Author Nakagiri, Yoshitada| Maruyama, Toshinori| Goto, Sachiko| Azuma, Yoshiharu| Shibuya, Koichi| Tamura, Eri| Tanimoto, Eriko| Torii, Fumiko| Takeda, Yoshihiro| Sugita, Katsuhiko|
Abstract 幼小児を含めた若年者の股関節X線撮影検査においては鉛板などで生殖腺を防護して行うのが通常である。男性の場合は生殖腺は体外に露出しているので,それを鉛板で包むようにすればある程度目的は達成される。しかし,女性の場合,生殖腺は骨盤腔内に存在するため,卵巣及び子宮を防護でき診断目的領域にかからないように鉛板を成形し,腹壁上に置いて撮影する。X斬写真上ではグリッドで散乱線を除去しているため,鉛板の陰影がくっきりと撮影され,生殖腺は完全に防護されているように見える。しかし,体内では散乱線によるかなりの被曝があるものと考えられる。そこで今回,鉛板下の散乱線量を鉛板幅及び電圧を変化させ,ファントム内各深さの散乱線量を測定した。その結果,鉛板下の散乱線量が相当量認められ,その量は深さ3~4cmでピークを形成した。鉛板幅による変化は幅が狭いほど線量は大きくなり,電圧による変化は60kVと80kVを比べると80kVの方が多くなった。これを鉛板なしの場合と比較すると,ファントム内意さが増すにしたがい増大した。したがって,臨床において鉛板がずれて再撮影をすることのないよう細心の注意が必要であると考えられた。
Abstract Alternative Usually in a hip-joint radiographic examination for the youth including children, the gonads should be well protected with an appropriate lead shield etc. Since the male gonads are in the outside of the body, if covered with a lead shield, the shield can protect them. However, in the case of the female, since the gonads of exist in a pelvic cavity, the lead shield is cut to a specific pattern so that it can protect the ovaries and the womb, and it is set on the abdomen during the radiographic exposure. Since the scattered radiation on an X-ray film can be removed with the grid, the image of a lead shield is obtained clearly, and the gonads seem to be protected completely. The shield can not protect the gonads of the female from the scattered radiation, though it protects them almost completely from the primary X-rays beam. Therefore, the gonads have radioactive contamination from scattered radiation. Then, in order to estimate the amount of scattered radiation under the lead shield, the dose under the shield was measured by using a phantom in this research, changing lead shield width, the tube-voltage, and the monitoring depth of a phantom. As a results, the dose under the lead shield was observed considerably and showed the peak at the depth of 3 or 4cm. Therefore, it was thought that a careful caution was required for obviating lead shield in clinical.
Keywords 股関節X線撮影 (Radiography Examination of Hip-joint) 医療被爆 (Patient Dose) X線測定 (Dosimetry) 生殖腺防護 (X-rays Protection of the Gonads)
Publication Title 岡山大学医学部保健学科紀要
Published Date 2001-03-24
Volume volume11
Issue issue2
Start Page 59
End Page 64
ISSN 1345-0948
language 日本語
File Version publisher
NAID 120002313720
JaLCDOI 10.18926/11714
Title Alternative スクリーン/フィルム乳房撮影法における乳房線量測定システム
FullText URL 010_2_099_106.pdf
Author Goto, Sachiko| Azuma, Yoshiharu| Maruyama, Toshinori| Nakagiri, Yoshitada| Takeda, Yoshihiro| Sugita, Katsuhiko| Kadohisa, Shigefumi|
Abstract The average glandular dose to glandular tissue m mammography is generally assumed to be a function of beam quality (HVL), x-ray tube target material, tube voltage, breast thickness, breast composition and, to a lesser extent, x-ray tube voltage waveform. The average glandular dose is generally determined from published tables with knowledge of the above function. Tables for a high frequency x-ray generator are not yet published. In our study, the lookup tables for the average glandular dose were made at 28 kV (high frequency x-ray generator), employing a breast simulating tissue (0-100% adipose tissue, 0-100% glandular tissue) phantom for an Mo target - Mo filter source assembly. We tried to estimate breast composition from x-ray mammograms by digital image processing techniques, also using the simulating tissue phantom. Then the system that automatically calculates the average glandular dose from digitized clinical x-ray mammograms was built. It is considered that this system can contribute to objective evaluation of the average glandular dose.
Abstract Alternative 乳房X線撮影法において乳腺組織に対する平均放射線吸収線量,すなわち平均乳腺線量は放射線のリスクの最も有用な測定法であり,現在,乳房に対する線量の評価に用いられている指標である。一般に,平均乳腺線量は線質(HVL),X線管球ターゲット材料,管電圧,圧迫乳房厚さ,乳房構成および(ある程度)X線管電圧波形の関数であるとされている。平均乳腺線量は,上記の関数についての情報を備えた表が公表されており,一般にその表を使って決定されている。近年,インバータ式といわれる高周波X線発生装置が普及してきた。しかし,その装置用の表は,まだ公表されていない。我々の研究では,乳房組織をシュミレートするファントム(0~100%乳腺組織,0~100%脂肪組織)を使用して,28kVでMoターゲット―Moフィルタソースアセンブリーを備えた高周波X線発生装置のために,平均乳腺線量用のルックアップテーブルを作成した。同様に,乳房組織をシュミレートするファントムを使用して,乳房X線写真から,ディジタル・イメージプロセシング技術によって,乳房構成の評価を試みた。そして,ディジタイズされた臨床乳房X線写真から,平均乳腺線量を自動的に計算するシステムを構築した。サンプル数が少ないため断定はできないが,日本女性は,基準構成(50%の脂肪および50%の乳腺組織)と比較すると,脂肪が少ない傾向を分析結果は示唆していた。また,平均乳腺吸収線量の限度は,明確に規定されていないが,American College of Radiology(ACR)は4 mGyなどを推奨している。また日本では,3 mGyが推奨されているが,我々の撮影システムはこれらを十分満足していた。このように本システムは,平均乳腺線量の客観的な評価に寄与するとともに,DR(digital radiography)などに応用すると,すなわちルックアップテーブルをDRのコンピュータに保存しておけば,撮影後すぐに乳房構成および平均乳腺線量を算出できる可能性をもつ。
Keywords Screen/Film Mammography (スクリーン/フィルム乳房撮影法) Breast composition (乳房構成) Average glandular dose (平均乳腺線量) Entrance skin exposure (皮膚入射線量) Breast-equivalent material phantom (乳房組織等価ファントム)
Publication Title 岡山大学医学部保健学科紀要
Published Date 2000-03-24
Volume volume10
Issue issue2
Start Page 99
End Page 106
ISSN 1345-0948
language 英語
File Version publisher
NAID 120002313736
JaLCDOI 10.18926/11721
Title Alternative The influence of air attenuation in characteristic curve for mammographic screen-film system
FullText URL 010_2_091_098.pdf
Author Maruyama, Toshinori| Goto, Sachiko| Azuma, Yoshiharu| Nakagiri, Yoshitada| Shibuya, Koichi| Sugita, Katsuhiko|
Abstract マンモグラフィ専用装置を使用して,距離法で低エネルギー領域のX線におけるマンモグラフィ用増感紙/フィルムシステムの特性曲線を得るためには,空気滅弱の影響を考慮する必要がある。その影響について,実効エネルギーから空気減弱分を補正,照射線量測定による補正,Bednarek法を応用した新距離法の3種類の方法を使って検討した。さらに,一般撮影装置でも,マンモ用システムに対して距離法で特性曲線を作成し,エネルギ ーの変化による影響についても検討した。その結果,3方法の特性曲線およびグラディエント曲線は,新距離法が高濃度域でわずかにずれるもののほぼ一致した。新距離法に対する平均階調度,最大階調度の最大誤差は,2.7%,0.2%であり,一般撮影用装置の距離法と3方法との間では,一般撮影用装置の距離法に対して最大誤差は2.7%,1.5%であった。以上のことから,エネルギーの変化による特性曲線への影響はほとんどなく,低エネルギー領域での特性曲線は空気特配の補正を行うことのみで得られると考えられる。
Abstract Alternative It is necessary to take air attenuation into account when we use inverse square sensitometry to obtain characteristic curve for the mammographic screen-film system at low x-ray energies as used with the dedicated unit. Three kinds of the inverse square sensitometry approach of correcting by air attenuation obtained from effective energy, of correcting by exposure dosimetry and of using modified the technique of Bednarek were employed to investigated the influence of x-ray energy in the characteristic curves for the mammographic screen-film system. In addition, the inverse square sensitometry with the general radiographic unit was employed and the influence of x-ray high energy in the characteristic curves was also investigated for the same screeri-film system. Though characteristic curves and gradient curves of the new inverse square sensitometry were a little lower than the others in high-density region, the curves with three kinds of methods almost coincided. Maximum relative errors of average gradient and maximum gradient for modified the technique of Bednarek were found to be 2.7% and 0.2% among the others respectively. Moreover, maximum relative errors of gradient and maximum gradient for the inverse square sensitometry with the general radiographic unit were 2.7% and 1.5% among three kinds of methods with the dedicated unit respectively. It was considered that the characteristic curves for the mammographic screen-film system were little influenced by x-ray energy and could be obtained only by correcting air attenuation from above results.
Keywords マンモグラフィ (mammography) 低エネルギー領域 (low x-ray energy) 特性曲線 (characteristic curve) 距離法 (inverse square sensitometry) 空気減弱 (air attenuation)
Publication Title 岡山大学医学部保健学科紀要
Published Date 2000-03-24
Volume volume10
Issue issue2
Start Page 91
End Page 98
ISSN 1345-0948
language 日本語
File Version publisher
NAID 120002313929
JaLCDOI 10.18926/11733
Title Alternative Physical Properties of Screen-Film Systems - New System for Chest Radiography -
FullText URL 006_007_013.pdf
Author Goto, Sachiko| Yoshida, Akira| Nakamura, Nobue| Maruyama, Toshinori| Azuma, Yoshiharu| Shibuya, Koichi| Nakagiri, Yoshitada| Sugita, Katsuhiko| Honda, Mitsugi|
Abstract 胸部専用の新しい増感紙/フィルムシステムについて物理的画質特性を測定し、従来のシステムと比較を行った。測定した新システムは、日本コダックのインサイトシステムからHC/IT-1、富士メディカルシステムのADシステムからHG-M/UR-1、コニカのEXシステムからXG-S/ES-C である。従来のシステムとして富士メディカルシステムのHR-4/Super HR-S を使用した。その結果、新システムは22~73%感度は高く、特性曲線においては低濃度部を持ち上げ、最大コントラストは高濃度側にシフトしていた。空間周波数2cycles/mmで相対鮮鋭度を比較すると、新システムが10~30%程度の低下となっていた。ノイズは、濃度1.0で新システムが35~46%の減少となった。以上より、新システムは、縦隔部の濃度を上げ、粒状性の改善を重視した設計となっていることが分かった。
Abstract Alternative The new three screen-film systems, Kodack INSIGHT system HC/IT-1, Fuji AD system HG-M/UR-1, and Konica EX system XG-S/ES-C for chest radiography were evaluated. In addition, the conventional system Fuji HR-4/Super HR-S was measured for comparison with new systems. The evaluation method is as follows. The image quality characteristics, speed, contrast, resolution and granularity were measured. The sensitivity and contrast were determined by measuring the MTF (modulation transfer function) and NCTF (normalized contrast transfer function). The granularity was estimated by measuring the Wiener spectrum. The speed of the new systems were improved by 22% to 73%. The dinsities at the maximum gradient value were shifted to high density (2.0-2.7). However, they had 10% to 30% less resolution. The other hand, the granularities were improved by 21% to 37% at 1.0 density. These results suggested that the emphasis of new systems was put on improving the image quality of mediastinum region, maintaining performance of the conventional system.
Keywords 増感紙フィルム系 (screen-film system) 物理特性 (physical properties) 感度 (speed (film sensitivity)) コントラスト (contrast) 鮮鋭度 (resolution) 粒状性 (granularity)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1996-02-29
Volume volume6
Start Page 7
End Page 13
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313511
JaLCDOI 10.18926/11735
Title Alternative Clinical application of the contrast media containing soft drinks for the X-ray examination of the stomach
FullText URL 006_015_021.pdf
Author Shibuya, Koichi| Nakagiri, Yoshitada| Azuma, Yoshiharu| Goto, Sachiko| Maruyama, Toshinori| Sugita, Katsuhiko| Okura, Yasuhiko| Natsukawa, Koichi| Tandani, Nobuyoshi| Nobuhara, Eitaro| Morioka, Yasuki| Takeda, Yoshihiro| Hiraki, Yoshio|
Abstract 胃X線検査の被験者を増やし、検査を円滑に行う上で造影剤である硫酸バリウム懸濁液の飲みにくさが障害の一つとなっている。これを改善する目的で、懸濁液に市販の粉末清涼飲料を混入したところ、64.2%の人が通常のものよりも飲みやすいと答えた。臨床上も造影剤の付着が悪くなったり、胃の蠕動を促進する等の問題は生じず、有用であると考えられた。
Abstract Alternative Barium sulfate suspensions are disliked by many people. This is one of the obstacles to increase persons who consult doctors and to have medical examinations smoothly. We mixed soft drinks into the suspensions to improve this problem. As a result, they were popular among 64.2% people, there were not any clinical troubles that the suspensions did not stick to the mucous membrane of the stomach well, the peristalsis of the sotmach were promoted, and so on. These results suggest that the contrast media containing soft drinks is useful for the X-ray examinations of the stomach.
Keywords 造影剤 (contrast media) 硫酸バリウム (barium sulfate suspension) 清涼飲料 (soft drinks) 消化管検査 (barium examination)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1996-02-29
Volume volume6
Start Page 15
End Page 21
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313345
JaLCDOI 10.18926/11750
Title Alternative Total Skin Electron Beam Therapy
FullText URL 001_001_006.pdf
Author Nakagiri, Yoshitada| Inamura, Keiji| Miyake, Hideaki| Tahara, Seiji| Mimura, Seiichi| Egusa, Tomomi| Mikami, Yasutaka| Yamada, Toshiharu| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract The peripherally T-cell lymphoma; Mycosis fungoides etc, has the good radiation sensitivity, and has been adapted for total skin electron beam therapy. In this study the pendular irradiation method was used for the purpose of total skin electron beam therapy in Mycosis fungoides, and physical data on the radiation field and the electron beam energy were useful clinically.
Abstract Alternative 皮膚に限局した一連の末梢型T細胞リンパ腫は放射線に対する感受性が高く、電子線治療の適応となる疾患である。こららの疾患は一般的に全身の皮膚に浸潤するため、治療に際してはTarget Volumeの深さに合わせた最小限のエネルギーで全身隈なく照射する必要がある。筆者等は最近臨床で遭遇した菌状息肉症の患者を治療するため、その患者に合った物理的なデータを測定した。照射野の拡大には振子照射法を用い、エネルギー低減方法は装置に装備されている鉛のスキャタラーを低原子番号で、しかも加工のしやすい塩化Vinyl板に交換する方法を工夫した。データとして治療効果、副作用に関係する線量率、エネルギー、及び照射野内平坦度について測定した結果、距離が長くなる関係から線量率が低下する全身照射法の欠点は解消できなかったが、エネルギー及び平坦度については使用可能なデータを得ることができた。
Keywords 電子線全身照射法 菌状息肉症 全身性皮膚疾患
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 1
End Page 6
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313887
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
JaLCDOI 10.18926/11766
Title Alternative Basic properies of beam flatness analyzer (THEBES 7000)
FullText URL 007_1_023_027.pdf
Author Nakagiri, Yoshitada| Oguri, Nobuhiro| Maruyama, Toshinori| Okawa, Yoshihiro| Wakasa, Hiroyuki| Nagaya, Isao| Azuma, Yoshiharu| Shibuya, Koichi| Goto, Sachiko| Mikami, Yasutaka| Inamura, Keiji| Morioka, Yasuki| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract 癌の有力な治療法の1つである放射線治療はシステム全体の許容誤差が±5%と、正確な治療が要求されている。正確な線量を正確な場所に照射されなければならない。そのためには日頃から照射装置のQuality Control が重要である。Beam平坦度の測定はその中でも、重要な項目で1/6月の測定頻度が勧告されている。今回、市販のBeam Flatness Analyzer (7000型 THEBES) を使用する機会を得たので、その基礎的性能であるChamber 相互の感度のちがい、測定値の再現性、識別可能な最小線量について実験を行った。各項目とも誤差が非常に少なく、日常の使用に際してそのデータは十分信頼できるものであることがわかった。
Abstract Alternative Lrradiation, which is one of the effective therapies to Cancer, is required to be accurate within ±5% of the tolerable error of the total system. An accurate dose has to be irradiated accurately at a target volume. For that Quality Control of the irradiation equipment is cotinually important. As the measurement of Beam Flatness is an important item, it is obligated to be measured once a week. In this paper as we have an opportunity to use a Beam Flatness Analyzer sold on a corporation of medical instrument, we experiment about the difference of sensitivity of mutual Chamber which is its basic property, the reproducibility of the measured score, and the minimum value of measuralbe dose. We find that the difference in every item is so small that its data is very reliable in a daily use.
Keywords 放射線治療 (radiation therapy) ビーム平坦度 (beam flatness) 性能評価 (valuation of property) 電子加速器 (electron accelerator)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1996-09-30
Volume volume7
Issue issue1
Start Page 23
End Page 27
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313499
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 10.18926/11808
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 10.18926/11820
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 10.18926/11849
Title Alternative Physical Image Quality of Rapid Processing Films
FullText URL 003_099_104.pdf
Author Yoshida, Akira| Honda, Mitsugi| Nakamura, Nobue| Arioka, Tadashi| Kobashi, Toshimi| Takeuchi, Tomoyuki| Mikami, Yasutaka| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract The imaging properties of Konica "new" SR series films and "old" MG-SR series films for rapid processing were measured in combination with green-emitting intensifying screens. The measured image quality prarameters include: characteristic curve, modulation transfer function (MTF) and Wiener spectrum. The relative speeds of the new SR series systems were slower than those of the old MG-SR series systems from 10 to 25%. The MTF's of the new systems were generally comparable to those of the old systems, except that SR-G system was improved with an increase of approximately 10%. In the Wiener spectrum measurement, however, the new systems showed from 10 to 35% decrease in low-frequency noise.
Keywords Rapid Processing Films Image Quality Characteristic Curve MTF Wiener Spectrum
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 99
End Page 104
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002314046
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 10.18926/11878
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 10.18926/11886
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 10.18926/11931
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 10.18926/11934
Title Alternative Granularity of Asymmetric Screen-Film System
FullText URL 005_105_110.pdf
Author Honda, Mitsugi| Yoshida, Akira| Nakamura, Nobue| Mimura, Seiichi| Kadohisa, Sigefumi| Mikami, Yasutaka| Azuma, Yoshiharu| Takeuchi, Tomoyuki| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract 非対称増感紙フィルム系について、両面乳剤フィルムのウィナースペクトル測定に及ぼす影響を検討した。濃度0.5~2.5のノイズ試料のフロント乳剤、バック乳剤、支持体層それぞれで測定したスペクトルの和と、両面同時に測定した全スペクトルとを比較した。その結果、全ウィナースペクトルの値は、フロント乳剤、バック乳剤の和より高くなった。また、試料濃度が高いほど、その差は大きくなった。これらは、マイクロデンシトメータの光学系の配置と両面乳剤フィルムの構造に起因している。したがって、非対称システムのようにフィルムの前面と後面で特性を分けて考える場合、注意を要する。
Abstract Alternative We have examined a factor affecting the Wiener spectrum measurement of double-emulsion film. An asymmetric screen-film system (Kodak HC/INSIGHT system) was used in this study. The results indicated that the total Wiener spectra of double-emulsion films are higher than the sum of spectra obtained with the front emulsion and back emulsion separately. These differences are attributed to the arrangement of the optical system of the microdensitometer used to measure and the structure of double-emulsion film.
Keywords 非対称増感紙フィルム系 (asymmetric screen-film system) 両面乳剤フィルム (double-emulsion film) ウィナースペクトル (Wiener spectrum) 粒状性 (granularity) マイクロデンシトメータ (microdensitometer)
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 105
End Page 110
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313805
JaLCDOI 10.18926/11936
Title Alternative The contrast media containing soft drinks for X-ray examination of the stomach
FullText URL 005_111_114.pdf
Author Shibuya, Koichi| Nakagiri, Yoshitada| Azuma, Yoshiharu| Goto, Sachiko| Sugita, Katsuhiko| Okura, Yasuhiko| Tandani, Nobuyoshi| Nobuhara, Eitaro| Mikami, Yasutaka|
Abstract 胃検診の受診者を増やし、検査を円滑に行う上で、造影剤である硫酸バリウム懸濁液の飲みにくさが障害の一つとなっている。これを改善する試みとして、懸濁液に市販の粉末清涼飲料を混入し検討したところ72.1%の人から通常のものよりも飲みやすいという回答を得た。今後、臨床的な検討を加えながら、さらに創意工夫していく必要がある。
Abstract Alternative Barium sulfate suspensions are disliked to drink by many people. That is one of the obstacles to increse person who consult doctors and to have medical examinations smoothly. We mixed soft drinks into the suspensions to improve this problem. As a result they were popular among 72.1% people. We need to study about these suspensions further, adding the clinical matters.
Keywords 造影剤 (contrast media) 硫酸バリウム製剤 (barium sulfate suspension) 粘度 (viscosity) 飲みやすさ (easiness to drink)
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 111
End Page 114
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002313324
Author Shibuya, Koichi| Nakagiri, Yoshitada| Azuma, Yoshiharu| Sugita, Katsuhiko| Kobashi, takao| Okura, Yasuhiko| Tandani, Nobuyoshi| Mikami, Yasutaka| Hiraki, Yoshio|
Published Date 1995-06-30
Publication Title 岡山医学会雑誌
Volume volume107
Issue issue1-6
Content Type Journal Article
Author Nakagiri, Yoshitada| Yamada, Toshiharu| Sugita, Katsuhiko| Mikami, Yasutaka| Ohkawa, Yoshihiro| Inamura, Kenji| Oguri, Nobuhiro| Nagaya, Isao| Noriyasu, Toshiaki| Okazaki, Yoshio| Inoue, Nobuhiro| Togami, Izumi| Hiraki, Yoshio|
Published Date 1990-02
Publication Title 岡山医学会雑誌
Volume volume102
Issue issue1-2
Content Type Journal Article