JaLCDOI 10.18926/15261
Title Alternative 現像温度および時間のマンモフイルム特性に与える影響
FullText URL 008_2_121_129.pdf
Author Maruyama, Toshinori| Goto, Sachiko| Azuma, Yoshiharu| Nakagiri, Yoshitada| Shibuya, Koichi| Sugita, Katsuhiko| Takeuchi, Tomoyuki| Honda, Mitsugi| Yoshida, Akira|
Abstract The influence for developing temperature and processing time within film processing conditions was investigated using four mammographic films, Konica New CM, Fuji UM-MA HC, Kodak Min-R M and Kodak EB/RA (for rapid system). And Fuji UR-2, a double-emulsion film, was used as a control. Those sensitometric strips exposed by a sensitometer were processed in the different combinations of developing temperatures ranging from 28 to 36℃, processing times from 45 to 210 sec. Average gradient, relative speed and base plus fog obtained from the measured film characteristic curves were evaluated for the different developing temperatures and times. Fuji UR-2 was scarcely affected and mammographic films were greatly affected in the different combinations without an increase in base plus fog except EB/RA. In New CM, UM-MA HC and Min-R M, the average gradients and the relative speeds increased as the developing temperature was higher and the developing time was longer, but the increases were limit on the combination of 36℃ and 210 sec in New CM and UM-MA HC. In EB/RA, the average gradients were almost constant and the relative speeds increased slightly like the double-emulsion film. These results suggested that it would be possible to contribute to dose reduction and advancement of contrast in New CM, UM-MA HC and Min-R M by changing these processing parameters.
Abstract Alternative フィルム処理条件において,現像温度と処理時間に対する影響を4種類のマンモグラフィ用フィルムKonica New CM, Fuji UM-MA HC,Kodak Min-R M,迅速処理用Kodak EB/RAについて調べた。そして,比較基準用として両面乳剤フィルムFuji UR-2を用いた。感光計で露光したフィルムを現像温度28~36℃,処理時間45~210秒で処理した。特性曲線から得られたフィルム特性(平均階調度,相対感度,カブリ濃度)を異なる現像温度,現像時間に対して評価した。UR-2はほとんど影響を受けず,マンモグラフィ用フィルムは,カブリ濃度が上昇することなく,現像条件の影響を大きく受けた。New CM, UM-MA HC,Min-R Mは現像温度の上昇,処理時間の延長に伴い,平均階調度と相対感度は増加した。しかし,New CM, UM-MA HCの36℃,210秒で増加は限度に達した。EB/RAの平均階調度は一定で,相対感度は両面乳剤フイルムと同 様にわずかな増加であった。これらの結果は,New CM, UM-MA HC, Min-R Mにおいて,処理条件を変化させることにより,被曝低減,コントラスト向上に貢献できる可能性を示唆していた。
Keywords マンモグラフィ (Mammography) 現像処理パラメータ (Processing Parameter) 特性曲線 (Characteristic Curve) 平均階調度 (Average Gradient) 相対感度 (Relative Speed)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1998-01-31
Volume volume8
Issue issue2
Start Page 121
End Page 129
ISSN 0917-4494
language 英語
File Version publisher
NAID 120002307943
JaLCDOI 10.18926/15260
Title Alternative Examination of density and mixing ratio of barium preparations, using an originally created phantom
FullText URL 008_2_113_119.pdf
Author Shibuya, Koichi| Miyahara, Tomonori| Sumi, Kazuyuki| Okura, Yasuhiko| Miyake, Koichi| Okuda, Kazuhiro| Tandani, Nobuyoshi| Azuma, Yoshiharu| Goto, Sachiko| Maruyama, Toshinori| Nakagiri, Yoshitada| Sugita, Katsuhiko| Hiraki, Yoshio|
Abstract 胃Ⅹ線検査に造影剤として用いられる硫酸バリウム懸濁液の濃度を,簡便に,客観的に決定する目的で,歯科用アルギン酸塩印象材を用いて,コインの図柄を写しとったファントムを制作した。これを使って二種類の硫酸バリウム製剤の適正濃度(PD)を調べた結果,BARITOP PとBARICON MEALを単体,若くは混合した場合には,おおよそ,PD(W/V%)=0.75C+165(ただし,CはBARICON MEALの混合比(%))となった。また,BARICON MEALはコントラストが高く,精密検査に有利だと考えられ,BARITOP PとBARICON MEALを混合すると濃度の許容範囲が広がるため,通常の検査に都合がよいと考えられた。更に,このファントムは簡便に作成することができ,しかも,硫酸バリウム懸濁 液との親和性も良いことから,硫酸バリウム製剤やⅩ線TV装置の評価,増感紙・フィルム系の評価等にも応用できると考えられた。
Abstract Alternative A phantom copied designs of coins was created with alginate dental impression material to establish a objective, simple and easy method for deciding density of barium sulfate suspensions which are used for stomach X-ray examination as contrast media. As a result of examining proper density (PD) of two kind of barium preparations with this phantom, in case of BARITOP P and BARICON MEAL, PD were almost shown by the next equation : PD(W/V%)=0.75C+165(C meant content of BARICON MEAL (%)). As BARICON MEAL resulted in hight contrast, it was thought to be suitable for a close examination. Mixture of BARITOP P and BARICON MEAL was thought to be suited to a routine examination becouse of wide permissible level of density. This phantom would be able to apply to the test of balium preparations, X-ray TV systems, screen/film systems and so on.
Keywords 造影剤 (contrast media) 硫酸バリウム (barium sulfate suspension) 胃X線検査 (X-ray examination of the stomach) アルギン酸塩印象材 (alginate impression material) ファントム (phantom)
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1998-01-31
Volume volume8
Issue issue2
Start Page 113
End Page 119
ISSN 0917-4494
language 日本語
File Version publisher
NAID 120002307835
JaLCDOI 10.18926/15252
Title Alternative Extended-cycle processによる乳房撮影用増感紙/フィルムシステムの画質改善
FullText URL 009_2_083_090.pdf
Author Goto, Sachiko| Maruyama, Toshinori| Azuma, Yoshiharu| Nakagiri, Yoshitada| Takeda, Yoshihiro| Sugita, Katsuhiko| Kimura, Fumie| Kadohisa, Shigefumi|
Abstract Extended-cycle process is the term used for a processor in which the processing time has been prolonged usually to approximate 210 seconds. It has been known that the extended-cycle process of some single-emulsion films as used for mammography may enhance film contrast and increase film speed. So the speed was increased in lower speed and higher resolution system than conventional systems by means of using the extended-cycle process in this paper. We investigated how much the resolution of the system was kept. A single screen-single emulsion combination, Konica M-100/CM-H was employed as a low speed and high resolution system. This film after exposure was processed in the different combinations of developing temperatures, 30, 32 and 34℃, and processing time of 210 seconds. On the other hand, Konica M-200/CM-H was employed as a high speed system. This film was processed in the standard-cycle processing (34℃, 90 seconds). Those systems were compared on contrast, speed, screen-film blur and noise by a characteristic curve, MTF (modulation transfer function) and WS (wiener spectrum). Furthermore, the RMI 165 phantom was used to evaluate visibility of mammographic details of these systems. As a result, in the extended-cycle process at the developing temperatures of 32 or 34°C and processing time of 210 seconds for M-100/CM-H, it was possible to increase the speed as much as the higher speed system, M-200/CM-H. Then the contrast, the MTF and the visibility were also improved as compared to the higher speed system. Furthermore patient dose could be reduced at the developing temperature of 34℃ and processing time of 210 seconds in M-100/CM-H.
Abstract Alternative 通常,extended-cycle processは処理時間が約210秒に延ばされた現像機のために使われる用語である。乳房撮影に使われるような片面乳剤フィルムにおけるextended-cycle processは,フィルムコントラストを増し,感度をあげることが良く知られている。そこで,本論文ではextended-cycle processにより低感度,高解像度システムの感度を上げ,どの程度解像度が維持されるかを調べた。片面増感紙/片面フィルムの組合わせであるKonica M-100/CM-Hを低感度,高解像度システムとして用いた。露光後のフィルムは現像温度30,32, 34度,処理時間210秒の異なる組合わせで現像処理した。一方,高感度システムとしてKonica M-200/CM-Hを用い,このフィルムは標準現像(34℃,90秒)された。感度,増感紙/フイルムのぼけ,雑音に関して,特性曲線,MTF(modulation transfer function), WS(wiener spectrum)によってこれらのシステムを比較した。さらにこれらのシステムにおける乳房写真の細部視覚評価のためにRM165ファントムを使用した。その結果,M-100/CM-Hに対するextended-cycle process現像温度32, 34℃,処理時間210秒のextended-cycle processにおいて,高感度システムM-200/CM-Hと同等の感度を上げることが可能であった。そのとき,コントラスト,MTF,視覚的検出能も高感度システムより向上した。さらに,現像温度34℃,処理時間210秒では,被曝線量の低減が可能であった。
Keywords image quality mammography single screen-single emulsion film system high-resolution screen extended-cycle process
Publication Title 岡山大学医療技術短期大学部紀要
Published Date 1999-02-26
Volume volume9
Issue issue2
Start Page 83
End Page 90
ISSN 0917-4494
language 英語
File Version publisher
NAID 120002307881
JaLCDOI 10.18926/15204
Title Alternative Characteristic of GAFCHROMIC XR TYPE T dosimetry film
FullText URL 014_1_023_029.pdf
Author Kubotsu, Mariko| Nakagiri, Yoshitada| Ujifuku, Ayako| Taniguchi, Yukiko| Hachiya, Miho| Azuma, Yoshiharu| Goto, Sachiko| Maruyama, Toshinori| Aoyama, Hideki| Tahara, Seiji| Inamura, Keiji| Watanabe, Toshimitsu| Sugita, Katsuhiko|
Abstract 医療の高度化に伴い,近年では長時間のⅩ線透視を行うInterventional Radiology(IVR)手技が頻繁に行われ,副作用としての難治性放射線皮膚障害例の報告が増加している。確定的影響である放射線皮膚障害はしきい値を超えると発症し,線量に依存して障害の程度が重篤となるため,患者被曝線量の測定が重要である。しかし,IVRでは照射部位が多彩で,焦点-皮膚間距離が不安定なため,その測定方法は確立されていない。本研究では,近年IVR等低エネルギー線量測定用フイルムとして開発されたCAFCHROMIC XR TYPE T について性能評価を行い,患者皮膚入射面の被曝線量測定への応用の可能性について検討した。その結果,線量特性,線質特性,ネット値の安定性に良好な特性を示し,臨床に使用可能であったので報告する。
Abstract Alternative In recent years, interventional radiology (IVR) using which uses prolomged fluoroscopy has been performed frequently in clinical radiology. Also, reports of radiation skin injuries whose symptoms occur after IVR has been also increasing. These symptoms will become worse if the radiation induced skin injuries are caused by doses which are above the designated threshold, and the grade of injuries are dependent on dose. Therefore, it is important that patient skin dose is measured correctly. But when perfoming IVR, irradiation is complex pricedure, and there is a measurement error with an unfixed source-to-skin distance. So. in this paper, characteristics of GAFCHROMIC XR TYPE T (which are film for low energy X-rays) are performed. Then, they are decided whether the application to the skin surface incidence dose measurement whoud be posible. From these results usefull data can be obtainned; for exanmpe film characteristics, energy factors and stability of sensivility.
Keywords 患者被爆線量 (Patient Exposure dose) GAFCHROMIC XR TYPE T Radiochromic film Interventional Radiology (IVR) 測定精度 (Radiation dosimetry)
Publication Title 岡山大学医学部保健学科紀要
Published Date 2003-12-25
Volume volume14
Issue issue1
Start Page 23
End Page 29
ISSN 1345-0948
language 日本語
File Version publisher
NAID 120002307331
JaLCDOI 10.18926/15203
Title Alternative A study on the scattering exposure dose in radiotherapy.
FullText URL 014_1_015_022.pdf
Author Kawabe, Atsushi| Nakagiri, Yoshitada| Kobashi, Kazuki| Yasumura, Naoki| Yamashita, Takahiro| Goto, Sachiko| Maruyama, Toshinori| Shibuya, Kouichi| Sugita, Katsuhiko|
Abstract 現代の医療のなかで癌治療において不可欠な存在となった放射線治療。一方,放射線被曝はたとえわずかであってもリスクが伴い,厳しく規制されている。ただし医療被曝はこの限りになく,過去においては癌患者に放射線治療をおこなう際の患部以外の被曝についてはあまり問題視されなかった。これには癌の治療という前提に加え,長期生存の可能性が低く,存命中に晩発障害が発生することが低いと考えられていたからである。しかし,集学的治療が確立した今後の放射線治療においては完治する放射線治療患者が多くなり,治癒後の余命が長くなることが予測される。放射線被曝による確率的影響は閾値がなく,影響は当然現れるであろう。そこで,放射線治療をおこなう際の患者の散乱線被曝線量,治療室内散乱線量,さらに高エネルギー放射線発生装置を取り扱うときに問題となっている中性子を測定した。その結果,測定線量は治療患部外被曝,室内散乱線量ともに無視できない量であることがわかった。中性子については,人体に影響がある線量は検出されなかったが,中性子の存在は室内物品の放射化の可能性を示唆するもので定期的な測定管理が必要である。また,Ⅹ線撮影室用の防護衣による散乱線被曝の低減効果は放射線治療室では無意味であった。
Abstract Alternative In modern medicine, radiotherapy has proved indispensable in the treatment of cancer. However. radiation exposure is a health hazard. and is thus strictly regulated. In the past, incidental exposure was not considered to pose a considerable risk, and because radiotherapy was an effective treatment for cancer and because the possibility of the long-term survival was generally poor, the prevalence of radiation injury was thought to be low. In recent years, however, more patients are making complete recoveries, and it is believed that long-term survival is possible with future radiotherapy techniques. There is no threshold for the stochastic effects of radiation exposure, and thus such effects may be detected even at low levels. In the present study, we measured the radiation exposure due to scattered rays from the patient, incidental radiation levels in the radiotherapy room, and levels of neutron radiation. which is a problem when high-energy X-ray radiotherapy systems are used. The results showed that exposure due to scattered rays and incidental levels in the radiotherapy room cannot be dismissed. and that further investigation is warranted. As for neutron radiation, dosages were below those that are known to influence the human body, but regular measurement is necessary because it may induce radioactivity in otherwise benign equipment. In addition, a protective apron had no effect on the exposure due to scattered rays in the radiotherapy room.
Keywords 散乱線被曝 (Exposure of scattered rays) 中性子 (Neutron) 放射線治療 (Radiotherapy) 確率的影響 (Stochastic effect)
Publication Title 岡山大学医学部保健学科紀要
Published Date 2003-12-25
Volume volume14
Issue issue1
Start Page 15
End Page 22
ISSN 1345-0948
language 日本語
File Version publisher
NAID 120002307504
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
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
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
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 10.18926/11931
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 10.18926/11886
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 10.18926/11849
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 10.18926/11820
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 10.18926/11766
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 10.18926/11755
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 10.18926/11750
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