54 research outputs found
Electrical Cell-substrate Impedance Sensing (ECIS)法を用いた培養細胞の微細挙動の定量的評価法 - 細胞-細胞間隙と細胞-電極間隙の評価 -
We have proposed a mathematical model for the micro-dynamics for cultured cells measured with ECIS system for the detection of nanometer-order dynamics of cells cultured
on a small gold electrode and could separately evaluate cell-to-cell distance (A) and cell-to-substrate distance (h). For wide applications of this method, we constructed
mathematical models which express cell-to-electrode impedances for some kinds of confluent conditions. Based on this mathematical model, we defined new parameters S(A)
and S(h) in order to evaluate cell-to-cell distance and cell-to-substrate distance. As the application, we investigated the effect of X-irradiation to bovine aortic endothelial cell (BAEC). We analyzed the micro-dynamics of cells from the impedance of BAEC before and after X-irradiation. It was proved that the stimulation of 100 Gy X-irradiation to the BAEC resulted in the large scale of increase in the cell-to-cell distances (A), and the slight increase in the cell-to-substrate distances (h) accompany with continuous fluctuations.[背景] Electrical Cell-substrate Impedance Sensing (ECIS)は培養細胞の電気的計測により,その微細挙動を評価する工学的手法である。我々はECISを用いてこの微細挙動を細胞-細胞間隙と細胞-電極間隙に分離して推定することが可能な数学的モデルを提案してきた。本研究ではこの数学的モデルを使用して,Ⅹ線を照射した牛大動脈内皮細胞(bovine aortic endothelial cell : BAEC)の微細挙動の経時変化を評価した。 [方法と結果] ECISシステム(Model 1600R Applied BioPhysics)を用いてBAECのコンフルエント到達前後で計測を行い,数学的モデルを構築した。このモデルは細胞の微細挙動を検出するために重要な周波数レンジである1-10kHzにおいて測定結果とよく一致し,Cole-Cole円弧則に従う。さらに細胞-細胞間距離Aの増減に対応する校正定数S(A)と細胞-電極間距離hの増減に対応する校正定数S(h)を導入し,ベクトルインピーダンスの変化に対応した値を算出することで細胞の微細挙動を評価することとした。次に本法によりX線(150kV, 100Gy)を照射したBAECの微細挙動を評価した。Ⅹ線照射細胞では時間経過と共に抵抗成分の変化が支配的なインピーダンスの減少が確認された。この現象はS(A)の大きな増加とS(h)の微小な減少をもたらした。このパラメータの変化は細胞間隙が拡大したことを示しており,Ⅹ線照射による細胞内損傷により細胞密度が低下したと考えられた。 [結論] 本法は培養細胞の微細動態の変化を細胞-細胞間隙と細胞-電極間隙に分けてリアルタイムに定量評価することが可能であり,各臓器の細胞レベルでの薬物の治療効果や
Ⅹ線に対する耐性の評価に適応できるものと考える
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
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.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
Development of image analysis for detection of defects of BGA by using X-ray images
In the surface mount technology, Ball Grid Array (BGA) has been used in a production of PC boards, because of their excellent characters such as high density of the lead pin pitch, better lead rigidity and self-alignment during re-flow processing. This paper deals with the development of image analysis for the detection of defects at BGA solder joints in PC boards by using X-ray images. In the conventional IC boards, it is possible to detect defects of solder joints by visual inspection, because the lead of IC package is set on its outside. However, we can't detect visually defects at BGA solder joints, because they are hidden under the IC package. In a production line, the inspection of BGA in PC boards depends on the function test of electric circuits in the final process. To improve a cost performance and the reliability of PC boards, an inspection of BGA is required in the surface mount process. Types of defects at BGA solder joints are solder bridge, missing connection, solder voids, open connection and miss-registration of parts. As we can find mostly solder bridge in these defects, we pick up this to detect solder bridge in a production line. The problems of image analysis for the detection of defects at BGA solder joints are the detection accuracy and image processing time according to a line speed of production. To get design data for the development of the inspection system, which can be used easily in the surface mount process, it is important to develop image analysis techniques based on X-ray image data. At the first step of our study, we attempt to detect the characteristic of the solder bridges based on an image analysis. </p
Detection of defects at BGA solder joints by using X-ray imaging
In the surface mount technology, a ball grid array (BGA) has been used in the production of PC boards. This paper deals with the detection of defects at BGA solder joints in PC boards by using X-ray imaging. Types of defects at BGA solder joints are solder bridge, missing connection, solder voids, open connection and misregistration of parts. The problems of image analysis for the detection of defects at BGA solder joints are the detection accuracy and image processing time according to the speed of the production line. To get the design data for the development of the inspection system used in the surface mount process, it is important to develop image analysis techniques based on X-ray image data. At the first step of our study, we attempt to detect the characteristics of the solder bridges based on the image analysis technique. </p
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
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.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
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
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.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
The influence of air attenuation in characteristic curve for mammographic screen-film system
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 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
A study on the scattering exposure dose in radiotherapy.
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。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
Physical Properties of Screen-Film Systems - New System for Chest Radiography -
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。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
A study of x-rays protection in a hip-joint radiography examination
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 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
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