巻号一覧
14 巻 (1997)
- 3 号 p. 128-
- 2 号 p. 74-
- 1 号 p. 2-
14 巻, 2 号
選択された号の論文の4件中1～4を表示しています
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低コヒーレンス光干渉法を中心として春名 正光, 近江 雅人, 白石 偉久, 田尻 秀幸1997 年 14 巻 2 号 p. 74-82
発行日: 1997/05/05
公開日: 2012/08/27
ジャーナル フリーRecently, remarkable attention is focused on the low coherence interferometry in order to realize visualization of thin sections of biological tissue. In our experiment, a specific low coherence interferometer was developed to evaluate quantitatively the spatial resolution of the detected image of a fine test pattern. It was then found that the resolution was nearly 10μm along the depth and<10μm in the cross section. Moreover, in actual optical CT, it is necessary to determine as precisely the dimensions of a biological tissue as possible. To do this, the refractive index n and thickness t of the biological tissue should be measured simultaneously. We proposed and developed a new technique for simultaneous measurement of n and t based on the low coherence interferometry. The detail will be described in this paper. Recent activities of there methods for optical CT are also presented.抄録全体を表示PDF形式でダウンロード (2523K) -
浅井 義行, 尾崎 吉明, 窪田 英明, 松本 政雄, 金森 仁志1997 年 14 巻 2 号 p. 83-95
発行日: 1997/05/05
公開日: 2012/08/27
ジャーナル フリーIn the previous paper, we proposed a psychophysical RMS granularity σp for the evaluation of radiographic mottle [J. Photogr. Sci.,43,103 (1995)]. Moreover, we found that the density dependence of psychophysical Wiener spectrum Wp (ν)at the frequency near 2.0mm-1 has a good correlation with that ofσp2 [J. Photogr. Sci.,44,89(1996)].
In this paper, we supported the vahdity of σp by comparing with the subjective rating result for additional three medical X-ray films having the different characteristics, and we found more accurate equivalent spatial frequency between Wp(ν)and σp2. The equivalent frequencies were 2.0∼2.2mm-1 on 8000 lm⋅m-2 viewer and 1.6mm-1 on 1500 lm⋅m-2 viewer.抄録全体を表示PDF形式でダウンロード (1787K) -
山田 英彦, 奥村 泰彦, 大坊 元二, 丹羽 克味1997 年 14 巻 2 号 p. 96-103
発行日: 1997/05/05
公開日: 2012/08/27
ジャーナル フリーThe aim of this study was to review the basic points in the LSF measurements of the intensifying screen by MIC system(Microscope-Image intensifier-Charged coupled devicesystem). The results obtained were as follows:
There was a significant difference between the LSF calculated from the intensifying screen film combination and LSF obtained directly from the MIC system. The LSF obtained from the MIC system was much sharper. In the case of LSF measured for the combination of the intensifying screen and the film, multiple light reflection of the fluorescence occurred in the space between the intensifying screen and the emulsion layer of the film, and it is deduced from experiments that this contributed greatly to the impairment of sharpness. Controlling this phenomenon enables development of new system that will satisfy the opposing factors of high sensitivity and sharpness of the intensifying screen film combination.抄録全体を表示PDF形式でダウンロード (2343K) -
加藤 元浩, 藤田 広志, 原 武史, 遠藤 登喜子1997 年 14 巻 2 号 p. 104-113
発行日: 1997/05/05
公開日: 2012/08/27
ジャーナル フリーWe have been developing a computer-aided diagnosis(CAD) system for detecting clustered microcalcifications and masses on digital mammograms. In our recent study, we found that the automated breast-region- extraction algorithm used in this CAD system was not accurate sometimes when we increased the database and tested many mammograms. This algorithm was based on the breast-border determination technique. The purpose of this study is to modify and improve this technique and also to test it by increasing image data. In our revised technique, the weight of the location information of breast border and the differentiation of the image density profile were included, and the location of breast region on the film and the number of breasts imaged on the same film were also considered. The new technique was succeeded in the extraction of the breast region in 728 cases(98.8%) out of 737mammograms obtained from 8 different facilities.抄録全体を表示PDF形式でダウンロード (5404K)
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