-
原稿種別: 表紙
1992 年 48 巻 11 号 p.
Cover5-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 目次
1992 年 48 巻 11 号 p.
Toc5-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 目次
1992 年 48 巻 11 号 p.
Toc6-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
i-xvi
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
xvii-xx
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
畑川 政勝, 井上 誠, 庄垣 雅史, 岸本 健治, 吉田 梨影
原稿種別: 本文
1992 年 48 巻 11 号 p.
1932-1938
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
The modulation transfer function (MTF) has been used for evaluation of radiographic image quality. However, in digital radiographic system such as a computed radiography (CR), the MTF can not be used in the same way of an analog system for evaluation because digital system is not shift-invaliant system. Then, we suggest the "MTF_<final>" which includes geometric unsharpness, detector unsharpness, unsharpness of the sampling aperture and unsharpness of the display (Laser-printer). It is an analog component in the digital system and in agreement with the definition of the MTF. Furthermore, an overall aliasing has to be used with MTF_<final> for evaluating the digital system because it is one of the important factors of the digital system. The MTF_<final> and the overall aliasing can be obtained from the overall MTFs of the center alignment and the shifted alignment.
抄録全体を表示
-
山内 秀一, 藤田 広志, 杜下 淳次, 藤川 津義, 上田 克彦, 西原 貞光, 大塚 昭義
原稿種別: 本文
1992 年 48 巻 11 号 p.
1939-1944
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Sources of noise in a computed radiography (CR) were investigated by measuring three different Wiener spectra (WS) : (1) laser printer Wiener spectra including CR film, (2) Wiener spectrum of CR film (single emulsion), and (3) overall Wiener spectra. To measure the noise contributed by the laser printer, "image data" (i.e., image having a constant pixel value) were produced on a personal computer and were sent to the laser printer in the CR system. The noise level of laser printer was comparable to that of the CR film at low spatial frequencies (<4 cycles/mm), but the noise level at high spatial frequencies (>4 cycles/mm) was higher than that of the film. Laser printer Wiener spectra obtained in the perpendicular direction relative to the laser beam scanning direction were comparable at low spatial frequencies, but greater at high spatial frequencies, to those obtained in the parallel direction. And a spectral peak around 10 cycles/mm was obtained in the Wiener spectrum in the perpendicular direction. The peak is caused mainly by a banding artifact. Overall Wiener spectra in the parallel and perpendicular directions show the same tendency as those of the laser printer, but the noise level of the overall Wiener spectrum was increased mainly by X-ray quantum mottle at low spatial frequencies. In conclusion, the noise of laser printer greatly increases the overall Wiener spectrum at high spatial frequencies.
抄録全体を表示
-
川村 義文, 三沢 一郎, 山田 由美子
原稿種別: 本文
1992 年 48 巻 11 号 p.
1945-1951
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
A newly-developed ^<99m>Tc-MIBI was studied regarding its detectability and assessment of myocardial blood flow maldistribution in comparison with ^<201>TlCl in 9 patients with an ischemic heart disease and one patient with III°AV block. Using the polar mapping display generated from the exercise or resting SPECT image data, visual estimation of traces distribution (normal (N), reduced-uptake (R) and defect (D)) were done segmentally. In 10 cases (120 segments), the coincidence of the estimation (N, R and D) between ^<99m>Tc-MIBI and ^<201>TlCl images was 92.5%. Moreover, mean and cumulative counts in ^<99m>Tc-MIBI images were highly comparable in each segment with those in ^<201>TlCl images, although 1 out of 10 cases showed significantly lower values of the segrental mean and cumulative counts in ^<99m>Tc-MIBI images than in the ^<201>TlCl images. In conclusion, ^<201>TlCl and ^<99m>Tc-MIBI yielded comparable data in both the visual and quantitative evaluation in 9 of the 10 cases, suggesting that ^<99m>Tc-MIBI allows to assess regional myocardial blood flow distribution almost equally to ^<201>TlCl.
抄録全体を表示
-
富樫 厚彦, 星 光一, 栢森 亮
原稿種別: 本文
1992 年 48 巻 11 号 p.
1952-1956
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
X-rays were irradiated to a rod-type glass-sealed element of a thermoluminescence dosimeter (TLD), then the thermoluminescent value was measured on both sides of the X-ray incident and passage surfaces of the element. In view of the observed decrease in the value by 2〜15% on the side of the latter surface compared with the former, It is important for measurement of values having a small coefficient in the variation on diagnostic X-rays to make on a basis of the unification of photometric surfaces. The rate of the above decrease depends on the X-ray tube voltage and energy sensitivity correction filter attached to the element. Next, X-rays were irradiated to a TLD element using two kinds of filters (C and F type), then the relationship between the sensitivity ratio of these filters and the X-ray tube voltage were examined. As a result, we confirmed that a simple measurement of the effective energy for the diagnostic X-rays related to the sensitivity ratio and the incident energy curve with a combination of C and F filter types.
抄録全体を表示
-
長谷川 隆幸, 津田 政行, 瀬尾 誠, 戸高 秀晴, 笠原 賢治, 小川 智
原稿種別: 本文
1992 年 48 巻 11 号 p.
1957-1963
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Dosimetry data are presented for the 18 MV photon beam of a Varian Clinac 2100C dual energy linear accelerator. The clinical parameters of tissue-peak ratio (TPR), buildup region and surface dose, beam flatness and symmetry, isodose curves, dose rate dependence are discussed to 18 MV photon beam data. For the dose distribution of parallel opposed field with 18, 6, 10 MV related to this paper. We obtained 0.782 for the ionization ratio and 18.1 MV for the nominal energy with AAPM guidelines. Depth of the maximum dose for a 10×10cm^2 field at 100cm source-chamber distance (SCD) was 3.8cm. The relative surface dose increase with field size from 19.9% for a 5×5(cm)^2 field to 55.4% for a 40×40(cm)^2 field.
抄録全体を表示
-
東田 善治, 守部 伸幸, 肥合 康弘, 勝田 昇, 洞田貫 誠志, 平田 幸徳, 高田 卓雄, 小寺 吉衛, 藤村 良夫
原稿種別: 本文
1992 年 48 巻 11 号 p.
1964-1970
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
We have measured the physical imaging properties, such as absolute speeds, modulation transfer functions (MTFs), and Wiener spectra of a large number of screens with calcium tungstate (blue system) and rare earth (green system) phosphor materials used in Japan. We also analyzed systematically the potential of clinical applications of the blue and green systems by taking into account the relationships regarding absolute speed, MTF, and Wiener spectrum. The results have showed that the blue screen systems generally have higher resolution properties than the green systems at the level of comparable speed. However, noise properties were improved by the use of green screen systems at the same speed. These measurement and analysis are very useful in facilitating the proper selection of screen-film system in diagnostic radiology.
抄録全体を表示
-
福島 昇, 池田 耕治, 小林 保浩, 池田 睦, 下野 哲勇
原稿種別: 本文
1992 年 48 巻 11 号 p.
1971-1975
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
ターボFLASH法と最大輝度投影法によって描出した血管像は, 血管性病変及び腫瘍性病変の経時的な評価並びに病変の占拠部位の評価に有用である.なお, 本報告は日本放射線技術学会九州部会(平成4年6月7日 : 福岡市)に於て「Enhanced Snap Shot Angiogram」と題して口述発表した.
抄録全体を表示
-
丸石 博文, 砂屋敷 忠
原稿種別: 本文
1992 年 48 巻 11 号 p.
1976-1978
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
以上で光子についてのモンテカルロ計算は大体行えます.後に残るは, 角度の変換ですが, これはほとんど高校の数IIBの世界ですから, 自分でも確認してください.以下は上原の論文を丸写しします.
抄録全体を表示
-
畑川 政勝
原稿種別: Article
1992 年 48 巻 11 号 p.
1979-1984
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
1984-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
大久 敏弘
原稿種別: 本文
1992 年 48 巻 11 号 p.
1985-1990
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
嘉戸 祥介, 吉田 寿, 倉西 誠, 伊藤 一, 森 光一, 小西 稔
原稿種別: 本文
1992 年 48 巻 11 号 p.
1991-1996
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Aiming at the realization of PACS, a study was conducted on the present state of, and various problems associated with, X-ray film digitization using a He-Ne laser-type film digitizer. Image quality was evaluated physically and clinically. With regard to the gradation specificity, the linear specificity was shown in a dynamic range of 4 figures. With regard to resolution specificity, visual evaluation was performed using a Hawlet Chart, with almost no difference being found between the CRT and laser printer output images and the decrease in resolution becoming more pronounced as the sampling pitch became greater. Clinical evaluation was performed with reference to the literature. The general evaluation of the clinicians was that although there was some deterioration for all of the shadows, (I have read this many times, but can't understood the last part.) by performing each of the kinds of image-processing enhancement of diagnostic ability was achieved, with a diagnosis being possible. The problem of unhindered diagnosis due to the development of artifacts from optical interference of the grid images projected onto the clinical pictures and digitizer sampling pitch was studied. As countermeasures, the use of a highdensity grid and adoption of a low-pass filter were useful in impeding the development of artifacts. Regarding the operating problems, the inputting of index information requires a considerable number of manhours and a method of automatic recognition from digital data was introduced to overcome this problem. As future prospects, the concepts of a practical system of X-ray film digitization and a film-screen system adapted to digitization were described.
抄録全体を表示
-
増田 和浩
原稿種別: 本文
1992 年 48 巻 11 号 p.
1997-2002
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
現状のディジタルシネ装置では, シネフィルムと比較して, 空間分解能, 時間分解能, 濃度分解能がデータ的に劣っていることは否定できない.また, 画像データの互換性を持たないことや観察系の未整備, その他テレビジョン系から受ける制約もある.しかし, 臨床上での評価は必ずしもアナログシネ装置に劣るというわけではない.また, ディジタル化に伴う様々な特長と共に, 時代の流れは着実にディジタルシネ装置の方向へ進んでいる.今後, ディジタルシネ装置をどう活用し, どのような装置に育てて行くかは, 今正に我々に課せられた使命であると言っても過言ではないだろう.ディジタル化を行うことが, すべての点において優れているわけではないことを十分に留意したうえで, Digital cine imaging technologyの完成に向けて検討を重ねて行くことが重要であると考える.いずれにしても, 患者さんを中心に考えたチーム医療の中で有益なディジタル化が進んで行くことを願って止まない.
抄録全体を表示
-
奥山 康男
原稿種別: 本文
1992 年 48 巻 11 号 p.
2003-2009
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
The current status and remaining problems of digital image processing in nuclear medicine were discussed. Digitalization of nuclear medicine images has made it possible, in conjunction with computers, to obtain new information (Fourier analysis, Factor analysis, etc.) with added value from images, in place of the fixed concepts that had formerly been drawn only from images. However, the basis of this technology is the special QC and QA of nuclear medicine examinations, and those techniques have not yet been adequately established. The advantage of digitalization is the flexibility that comes from the program, but the element of the subjectivity of each individual plays a large role, and it can be said that there is also the risk that the logic of image diagnosis established to date will be destroyed. Accordingly, the creation of digital image processing techniques with specifications will give birth to standardized digital nuclear medicine images, and these developments will certainly lead to progress in nuclear medicine diagnosis. In addition, in comparison with other modalities, the field of nuclear medicine involves a lesser amount of information, and this simplifies the digitalization of images. At present, equipment is being designed and developed with incorporation of the concept of a work station. A serious problem that remains in this field is the standardization of image transmission. In summary, the main problem that must be solved in the field of nuclear medicine examinations is the establishment of QC and QA methods and practical algorithms for the software. It is hoped that there will be open access to information, etc., related to the software.
抄録全体を表示
-
大山 永昭
原稿種別: 本文
1992 年 48 巻 11 号 p.
2010-2015
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Image processing is being widely used in the medical field and already has become very important, especially when used for image reconstruction purposes. In this paper, it is shown that image processings can be classified into 4 categories : passive, active, intelligent and visual image processing. These 4 classes are explained at first through the use of several examples. The results shows that the passive image processing does not give better results than the others. Intelligent image processing, then, is addressed, and the simulated annealing method is introduced. Due to the flexibility of the simulated annealing, formulated intelligence is shown to be easily introduced in an image reconstruction problem. As a practical example, 3D blood vessel reconstruction from a small number of projections, which is insufficient for conventional methods to give good reconstruction, is proposed, and computer simulation clearly shows the effectiveness of simulated annealing method. Prior to the conclusion, medical file systems such as IS & C (Image Save and Carry) is pointed out to have potential for formulating knowledge, which is indispensable for intelligent image processing. This paper concludes by summarizing the advantages of simulated annealing.
抄録全体を表示
-
安藤 裕
原稿種別: 本文
1992 年 48 巻 11 号 p.
2016-2022
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
For the PACS (picture archiving and communication system), large strage capacity recording media and a fast data transfer network are necessary. When the PACS are working, these technology requirements become an large problem. So we need image data compression having a higher recording efficiency media and an improved transmission ratio. There are two kinds of data compression methods, one is reversible compression and other is the irreversible one. By these reversible compression methods, a compressed-expanded image is exactly equal to the original image. The ratio of data compression is about between 1/2 and 1/3. On the other hand, for irreversible data compression, the compressed-expanded image is a distorted image, and we can achieve a high compression ratio by using this method. In the medical field, the discrete cosine transform (DCT) method is popular because of the low distortion and fast performance. The ratio of data compression is actually from 1/10 to 1/20. It is important for us to decide the compression ratio according to the purposes and modality of the image. We must carefully select the ratio of the data compression because the suitable compression ratio alters in the usage of images for education, clinical diagnosis and reference.
抄録全体を表示
-
滝沢 正臣
原稿種別: 本文
1992 年 48 巻 11 号 p.
2023-2029
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Diagnostic image management system, such as PACS, will radically change the way of carrying out radiology and patient care in hospitals. A typical PACS can be interfaced with other imaging systems such as CTs, and with a standardization of data communication, it becomes possible to communicate between numerous devices including hospital information systems. The ACR-NEMA and MIPS standard promote communication of digital image information, regardless of the source format of the device set up by the manufactrurer, facilitate the development and expansion of PACS and hospital information system, allowing the creation of diagnostic information databases. Although such standardization is available, they are not widely used in hospitals yet. This paper described that the essential functions regarding the ACR-NEMA and MIPS standard, and their problems inherent under the current standardization.
抄録全体を表示
-
遠山 坦彦
原稿種別: 本文
1992 年 48 巻 11 号 p.
2030-2032
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
加賀 勇治
原稿種別: 本文
1992 年 48 巻 11 号 p.
2033-2035
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
Rotato-Stereography, new angiographical method, equipped with a digital angiography system has remarkable advantages and clinical usefulness. Three dimensional vascular structure can be easily recognized, because arteries and veins are displayed as rotational movie at real time on TV monitor. We summarized the present state and discussed problems of the rotato-stereography which seems to be one of the most important methods of digital anigography.
抄録全体を表示
-
倉西 誠
原稿種別: 本文
1992 年 48 巻 11 号 p.
2036-2038
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
宮崎 茂, 篠原 文章, 井手 敏典, 上遠野 昭
原稿種別: 本文
1992 年 48 巻 11 号 p.
2039-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
著者 千田浩一先生へ本会会誌第48巻第4号(1992年)に掲載されました上記表題の論文につきまして次の2点についておたずね致します.
抄録全体を表示
-
千田 浩一, 有馬 宏寧
原稿種別: 本文
1992 年 48 巻 11 号 p.
2040-2041
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
本学誌(第48巻4号, 1992年)に掲載されました上記標題の論文の討論(第48巻11号, 1992年)に対する回答とわれわれの見解を下記のように述べます.
抄録全体を表示
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
2042-2045
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
2045-2048
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
2049-2051
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
2051-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 付録等
1992 年 48 巻 11 号 p.
2051-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー
-
原稿種別: 表紙
1992 年 48 巻 11 号 p.
Cover6-
発行日: 1992/11/01
公開日: 2017/06/29
ジャーナル
フリー