研究者詳細 - 後藤　佐知子

論文 - 後藤　佐知子

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頚部MRI脂肪抑制T1強調画像における磁化率アーチファクト軽減補助具（Sat-Pad）の作製査読

木田勝博, 後藤佐知子, 梶谷努, 東義晴

岡山赤十字病院医学雑誌 22 ( 1 ) 27 - 30 2011年

記述言語：日本語出版者・発行元：岡山赤十字病院医学雑誌編集委員会

MRIにおいて軟部組織と空気境界面は、磁化率変化によるアーチファクトが起こりやすい。通常、MRIでは脂肪抑制法が頻繁に用いられるが、磁化率の変化は脂肪抑制のムラを引き起こす。その脂肪抑制ムラは、解剖学的な形状のために、頸部で頻繁に生じる。本研究では、磁化率変化を軽減する補助具(Sat-Pad)の作製を試みた。(著者抄録)

高エネルギーX線に対するRadiochromic filmの濃度測定精度の検討査読

青山英樹, 東義晴, 後藤佐知子, 田原誠司, 宇野弘文, 稲村圭司, 門久繁文, 中桐義忠, 金澤右, 住本哲宏, 東眞美

日本放射線技術学会雑誌 60 ( 11 ) 1533 - 1542 2004年

記述言語：日本語出版者・発行元：公益社団法人日本放射線技術学会

Radiochromic film (RC-film) is of great interest as a film-type dosimeter for radiation oncology applications. We present a two-dimensional image-based evaluation of the measurement accuracy of a commercial RC-film product (Gafchromic MD-55-2 film, ISP TECHNOLOGIES, Inc.) by using a commercial Laser Densitometer (Model 1710, Computerized Medical Systems, Inc.) as an optical density imaging system. The coefficient of variation of the density (pixel-value) in one sample was approximately 3% to 11 % at 3 Gy or less, and 3% or less at 4 to 60 Gy. Although the coefficient of variation between three samples at the same dose was about 14% at 1 Gy, it decreased as the dose increased, reaching several percent. In 1 to 6 Gy samples, geometric imaging artifacts [interference (moire) patterns] were observed, and it was found that scan-sampling pitch influenced the accuracy of measurement of the density of the sample. To improve the accuracy of density measurement, sufficient knowledge about characteristic features of the density measuring system is essential.

DOI： 10.6009/jjrt.KJ00003326577

放射線治療時の治療部外散乱被曝線量に関する研究査読

川辺睦, 中桐義忠, 小橋一輝, 安村直樹, 山下剛央, 後藤佐知子, 丸山敏則, 杉田勝彦

岡山大学医学部保健学科紀要 2003年

線量測定用 GAFCHROMIC XR TYPE T の特性査読

窪津真理子, 中桐義忠, 氏福亜矢子, 谷口友季子, 八谷美穂, 東義晴, 後藤佐知子, 丸山敏則, 青山英樹, 田原誠司, 稲村圭司, 渡邊敏充, 杉田勝彦

岡山大学医学部保健学科紀要 2003年

Estimating AverageGlandular Dose by Measuring Glandular Rate in Mammograms 査読

Sachiko Goto, Yoshiharu Azuma, Tetsuhiro Sumimoto, Shigeru Eiho

MEDICAL IMAGING TECHNOLOGY 21 ( 5 ) 369 - 376 2003年

Estimation of the digitized mammographic breast density by the histogram approach using the neural network

Sachiko Goto, Yoshiharu Azuma, Tetsuhiro Sumimoto, Yoshihiro Takeda, Shigeru Eiho

Proceedings of the 8th International Workshop on ADC Modelling and Testing, IWADC 2003 2003年

記述言語：英語掲載種別：研究論文（国際会議プロシーディングス）出版者・発行元：Universita degli Studi di Perugia

Our aim was to improve the accuracy of classifying x-ray mammographic breast densities. The histogram approach using the neural network was used for the purpose of constructing a flexible system. In this study the phantom of the synthetic breast-equivalent resin material for the process of the A/D conversion of mammograms was employed. The digital values can offset the difference in characteristics between the mammography system, the unit, etc. Furthermore the features of our system use the neural network, and then tune the neural network by the histogram of the digital values and by the radiologists' and expert mammographers' assessment ability. Although there was an observer's bias, our system was able to classify the breast density automatically according to that observer. This is only possible if the observer has been trained to some extent and is capable of maintaining an objective assessment according to the assessment criteria.

発泡剤とバリウムの投与順序の相違による飲みやすさと流出程度査読

澁谷光一, 三宅浩, 大枝嗣人, 藤照正, 中桐義忠, 東義晴, 丸山敏則, 後藤佐知子, 杉田勝彦, 平木祥夫

日本放射線技術学会雑誌 57 ( 4 ) 440 - 443 2001年

記述言語：日本語出版者・発行元：公益社団法人日本放射線技術学会

Rates of Flow of barium meal into the bowel and ease of swallowing a barium meal and foaming agent were investigated according to the procedure of administration, in order to study the timing of adding the foaming agent. In group medical examinations, the flow rates of barium meals of 100 examinees given a barium meal followed by a foaming agent were compared with those of the same examinees given the foaming agent first. Parasympatholytic agents were not administered in this study. When the foaming agent was given before the barium meal, the flow rate of the barium meal into the bowels was 44.0%. In contrast, when the foaming agent was given after the barium meal, the rate was 78.0%. A total of 67.3% of 101 Volunteers given the foaming agent and the barium meal twice in the reverse order answered that it was easier to swallow the barium meal first. When a parasympatholytic agent is not given, it is better to give the foaming agent first, even though it is more difficult to swallow the barium meal after the foaming agent, because it is most important in examination of the stomach that the barium meal does not flow out into the bowel.

DOI： 10.6009/jjrt.KJ00001357562

股関節X線撮影時の女性生殖腺防護についての検討査読

中桐義忠, 丸山敏則, 後藤佐知子, 東義晴, 澁谷光一, 田村恵里, 谷本江利子, 鳥居史子, 竹田芳弘, 杉田勝彦

岡山大学医学部保健学科紀要 11 ( 2 ) 59 - 64 2001年

記述言語：日本語出版者・発行元：岡山大学医学部保健学科

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。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 themale 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.

その他リンク： http://search.jamas.or.jp/link/ui/2001185919

股関節X線撮影における女性生殖腺の防護について査読

中桐義忠, 丸山敏則, 後藤佐知子, 谷本江利子, 田村恵里, 鳥居史子, 渋谷光, 東義晴

岡山県放射線技師会会誌 2001年

片面増感紙/片面乳剤フィルムシステムの特性－空気減弱によるX線エネルギーの影響－査読

丸山敏則, 後藤佐知子, 東義晴, 中桐義忠, 住本哲宏, 山本秀樹

電子情報通信学会技術研究報告 101 ( 434 ) 1 - 8 2001年

担当区分：責任著者記述言語：日本語出版者・発行元：一般社団法人電子情報通信学会

低エネルギー領域のマンモグラフィに使用される片面増感紙/片面乳剤フィルムシステムの特性曲線作成に対しては空気減弱が問題となる.そこで, 異なるX線エネルギー励起におけるマンモグラフィ用増感紙の蛍光スペクトルを測定し, 増感紙の蛍光発生に対するエネルギーによる影響を検討した.またマンモグラフィ専用装置の低エネルギーX線を用いて, 距離によって連続的に変化するエネルギー分布に対応した空気減弱のより正しい補正を試みた.さらに一般撮影領域のX線エネルギーを用いて作成した特性曲線とマンモグラフィ専用装置の低エネルギーX線を用いて空気減弱分を補正して得られた特性曲線を比較した.その結果, 空気減弱分が無視できるX線エネルギーを選択すれば, 特性曲線を作成できる可能性が得られた.

Breast Dosimetry System in Screen/Film Mammography 査読

Sachiko GOTO, Yoshiharu AZUMA, Toshinori MARUYAMA, Yoshitada NAKAGIRI, Yoshihiro TAKEDA, Katsuhiko SUGITA, Shigefumi KADOHISA

Bull Fac Health Sci, Okayama Univ Med Sch 10 ( 2 ) 99 - 106 2000年

担当区分：筆頭著者記述言語：英語出版者・発行元：岡山大学医学部保健学科

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 averageglandular dose.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。

発泡剤と硫酸バリウム造影剤の投与順序の検討査読

澁谷光一, 大枝嗣人, 三宅浩ー, 丹谷延義, 中桐義忠, 東義晴, 丸山敏則, 後藤佐知子, 杉田勝彦, 平木祥夫

日本放射線技術学会誌 56 ( 4 ) 605 - 609 2000年

記述言語：英語出版者・発行元：公益社団法人日本放射線技術学会

Two kinds of gastric images of 85 examinees were compared in order to study the procedure of giving barium meal and forming agents The more recent images were obtained with examinees given a barium meal followed by a forming agent, whereas the other images were of the same examinees obtained the previous year, with the foaming agent given before the barium meal. Results showed that when the barium meal was given first, the mucous membrane of the stomach was imaged better. In contrast, when the forming agent was given first, sodium tartrate, derived from the foaming agent, was considered to cover the mucous membrane and physically to prevent the barium meal from clinging to the membrane.

DOI： 10.6009/jjrt.KJ00001356895

マンモグラフィにおけるextended-cycle processの応用－描出能向上への効果－査読

丸山敏則, 後藤佐知子, 東義晴, 中桐義忠, 杉田勝彦

日本放射線技術学会誌 56 ( 11 ) 1339 - 1347 2000年

担当区分：責任著者記述言語：日本語出版者・発行元：公益社団法人日本放射線技術学会

We applied an extended-cycle process, in which the processing time is longer than the manufacturer's recommendation, to a low-speed, high-resolution system in mammography and investigated to what extent sharpness, contrast, and speed would be maintained or increased and whether this process could be applied clinically. In this study, a single-screen/single-emulsion film, Konica M-100/CM-H, was used in the lowspeed, high-resolution system, and M-200/CM-H was employed for comparison. Developing temperatures of 30, 32, and 34 degrees centigrade and a processing time of 210 seconds were selected as conditions of the extended-cycle process. M-100/CM-H with the extended-cycle process(M-100/E system)and M-200/CM-H with the standard-cycle process were compared at 34 and 90 seconds(M-200 system)in terms of contrast, speed, modulation transfer function(MTF), and Wiener spectrum(WS). In addition, the visibility of mammograms obtained using an RMI 165 phantom was evaluated by the method of paired comparisons. In the comparison of the M-200 system with the M-100/E system at 34 and 210 seconds, the speed was almost equal and the average gradient and MTF value at 2.5 cycles/mm increased about 20% and 8%, respectively. Ws was higher due to the increase in quantum mottle with increases in the average gradient and MTF. In the scale of the method of paired comparisons, M-100/E systems showed better results. Moreover, entrance skin exposure in air of the M-100/E system at 34 and 210 seconds was almost equal to that of the M-200 system. These results suggested that it was possible to improve visibility by the extended-cycle process in a low-speed, high-resolution system.

DOI： 10.6009/jjrt.KJ00001357361

マンモグラフィ用フィルムにおけるExtended-cycle Processの基礎的研究-粒状度- 査読

東義晴, 後藤佐知子, 丸山敏則, 中桐義忠, 杉田勝彦

日本放射線技術学会雑誌 56 ( 7 ) 937 - 945 2000年

担当区分：責任著者記述言語：日本語出版者・発行元：公益社団法人日本放射線技術学会

With single-emulsion films like those used in screen/film mammography, if the developing temperature is higher and/or the processing time is longer than recommended (i.e., extended-cycle process), film speed and/or film contrast are effectively increased. However, it can also be expected that radiographic noise will be increased by the extended-cycle process. Therefore, film graininess and radiographic mottle were investigated with standard-and extended-cycle processes in four single-screen/single-emulsion film systems for mammography, the Konica M-150/New CM, Fuji UM MAMMO Fine/UM-MA HC, Kodak Min-R2000/Min-R2000, and Kodak Min-R Medium/Min-R M. Investigation was carried out by measurement of the Wiener spectrum (WS). Results showed that the WS of film graininess increased in all films. The increase was greatest in Min-R M, and the rate of increase at 2.0 cycles/mm was 1.67 or more. The film showing the smallest increase was UM-MA HC, for which the rate of increase was 1.03-1.21. There were cases in which the spatial frequency at a 50 percent contribution rate of film graininess to radiographic mottle changed to a low spatial frequency. When only the increase in WS of radiographic mottle was examined, the increase was greatest in Min-R Medium/Min-R M, and the rate of increase at 2.0 cycles/mm was 1.65 or more. Min-R2000/Min-R2000 showed the least increase, and the rate of increase was 1.12-1.24. Increases in WS values were larger at 0.1-0.5 cycle/mm than at 2.0 cycles/mm when investigating the influence of trend using film graininess, and roller marks and so on could not be specified as a cause.

DOI： 10.6009/jjrt.KJ00001357002

マンモグラフィ用増感紙/フィルムシステムの特性曲線における空気減弱の影響査読

丸山敏則, 後藤佐知子, 東義晴, 中桐義忠, 渋谷光ー, 杉田勝彦

岡山大学医学部保健学科紀要 10 ( 2 ) 91 - 98 2000年

記述言語：日本語出版者・発行元：岡山大学医学部保健学科

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。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 characteristiccurves 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.

その他リンク： http://search.jamas.or.jp/link/ui/2000278800

撮影条件からの腹部Ｘ線被曝線量の算定－岡山県下の現況－査読

中桐義忠, 丸山敏則, 後藤佐知子, 東義晴, 渋谷光一, 井上龍也, 門久繁文, 森岡泰樹

岡山県放射線技師会会誌 1999年

Improvement of image quality on mammographic screen-film system by extended-cycle process 査読

Sachiko GOTO, Toshinori MARUYAMA, Yoshiharu AZUMA, Yoshitada NAKAGIRI, Yoshihiro TAKEDA, Katsuhiko SUGITA, Fumie KIMURA, Shigefumi KADOHISA

Bull Fac Health Sci, Okayama Univ 9 ( 2 ) 83 - 90 1999年

記述言語：英語出版者・発行元：岡山大学医療技術短期大学部

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 increasefilm 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, KonicaM-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 andprocessing 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 atthe developing temperature of 34℃ and processing time of 210 seconds in M-100/CM-H.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｡

その他リンク： http://eprints.lib.okayama-u.ac.jp/15252

マンモグラフィ用フィルムにおけるフィルム粒状度の測定査読

後藤佐知子, 東義晴, 丸山敏則, 中桐義忠, 杉田勝彦

日本放射線技術学会誌 55 ( 11 ) 1115 - 1121 1999年

担当区分：筆頭著者記述言語：日本語出版者・発行元：公益社団法人日本放射線技術学会

Film graininess can be measured by providing air spaces between the screen and film in the screen-film system. In this study, the necessary air spaces were investigated to measure mammographic film graininess by using a mammography unit at the low tube voltage of 28 kV. Wiener spectra were measured with the screen held 1, 3, 6, 9,15, 21, and 30 mm from the film at densities of 0.8 and 1.3. Konica New CM film with a Konica M-150 screen was employed in this investigation. Results showed that Wiener spectral values were almost constant at densities of 0.8 and 1.3 when the air spaces were 9 mm or more. That is, it was considered that film graininess was evaluated independently by blurring quantum mottle, and 15 mm air spaces were used to provide a safety margin. Furthermore, film graininess of three mammographic films, Fuji UM-MA HC (with a Fuji UM MAMMO Fine screen), Kodak Min-R 2000 (with a Kodak Min-R 2000 screen), and Kodak Min-R M(with a Kodak Min-R Medium screen)were measured with 15 mm air spaces. Min-R 2000 film had the lowest Wiener spectral values for film graininess at low spatial frequencies.

DOI： 10.6009/jjrt.KJ00000921418

腹部単純X線撮影時の被曝線量 -岡山県下の病院の現況- 査読

中桐義忠, 東義晴, 丸山敏則, 渋谷光一, 後藤佐知子, 杉田勝彦, 森岡泰樹, 門久繁文, 井上龍也, 平木祥夫

環境制御 20 ( 20 ) 17 - 21 1998年

記述言語：日本語出版者・発行元：岡山大学環境管理センター

In 1995, we have published a paper about the basic data on the relation between X-ray exposure equipment and patient dose in Vol. 17 of the Journal "Environment Research and Control". In this time, we questioned hospitals in Okayama Prefecture about exposure equipments of abdomen. And we compared each hospital's exposure equipments with the basic data, calculated each patient dose, then we studied that differences. Various imaging system, for example; screen/film or imaging plate has been used at each hospitals, so that exposure are various and patient doses are very different. The exposure equipment decide that the X-ray photograph is good or bad, so we cannot treat it easily. But we think that we have to try to take X-ray photographs which are suit the purpose of diagnosis which as a small patient dose as possible.

The Influence of Film Processing Temperature and Time on Mammographic film Characteristics 査読

Maruyama Toshinori, Goto Sachiko, Azuma Yoshiharu, Nakagiri Yoshitada, Shibuya Koichi, Sugita Katsuhiko, Takeuchi Tomoyuki, Honda Mitsugi, Yoshida Akira

Bull.Sch.Health Sci.Okayama Uni. Vol.8 No.2 ( 2 ) 121 - 129 1998年

記述言語：英語出版者・発行元：岡山大学医療技術短期大学部

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 characteristiccurves 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 bepossible to contribute to dose reduction and advancement of contrast in New CM, UM-MA HC and Min-R M by changing these processing parameters.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｡

その他リンク： http://search.jamas.or.jp/link/ui/1998146743

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