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Article type: Cover
1984 Volume 40 Issue 2 Pages
Cover4-
Published: March 01, 1984
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Article type: Cover
1984 Volume 40 Issue 2 Pages
Cover5-
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Article type: Index
1984 Volume 40 Issue 2 Pages
Toc2-
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Article type: Appendix
1984 Volume 40 Issue 2 Pages
App1-_xxi_
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Article type: Appendix
1984 Volume 40 Issue 2 Pages
163-203
Published: March 01, 1984
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KAZUHIRO MIHARA, TATSUO FUJINO, KATSUHITO ABE
Article type: Article
1984 Volume 40 Issue 2 Pages
204-210
Published: March 01, 1984
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A multi-imaging camera was used for obtaining a hard-copy image from an imaging device of a CT scanner. The contrast and brightness of the CRT and time exposure of the camera were the three important factors which influenced the quality of the hard-copy image. Two kinds of original test patterns were designed to examine the characteristics of the factors. One was the grayscale test pattern which was used to obtain the a density curve. This curve, named the Film-CRT curve, (F-C curve) is to distinguish it from the H&D curve. The other was the sharpness test pattern which was used to examine the relationship between brightness and sharpness. As a result, the slope of F-C curve became steeper with a decrease in brightness, with an increase in contrast and with increase in exposure time. Sharpness became worse with an increase in brightness. Therefore, to obtain a good hard copy image, the brightness must be set as dark as possible, and the contrast and exposure time must be controlled after due consideration is given to their characteristics.
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SHINYA ITO, TOSHIKUNI KIKUCHI, YASUMITSU KAWAGOE, KUNIAKI SAKURAI, MIT ...
Article type: Article
1984 Volume 40 Issue 2 Pages
211-218
Published: March 01, 1984
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Delivering enough of a dose to a target tumor and avoiding unnecessary irradiation of the surrounding normal tissues as possible are of prime importance in radiotherapy. The most suitable treatment to obtain the therapentic ratio should be pursued. For this purpose, multilefdiaphragm conformation radiotherapy has been applied. In 1981,we purchased a NELAC-1018 linear accelerator and developed the mono-block conformation system controlled micro computer in combination with NEC staff. This system without a multileafdiaphragm and a cam is economical, however, the dose distribution of this system is confined only to an oval configuration. The program to represent the dose distribution of a mono-block conformation radiotheraphy using radiation planning computer MODULEX was made. In this report, the mono-block conformation system and its dose distribution are discussed. The dose distribution calculated by MODULEX was compared with the measured dose (Film technique, TLD and Ionisation chamber). 1) Dose distribution of 10MV X-ray mono-block conformation system was homogeneous in the target area. 2) Calculated dose was very close to measured dose. Calculated dose was precise enough to utilize for routine radiation planning.
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SHIGEATSU YAMAGUCHI, KATSUHIKO ABE, HARUYOSHI SHIMIZU
Article type: Article
1984 Volume 40 Issue 2 Pages
219-226
Published: March 01, 1984
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Measurements of neutron and X-ray dose reduction were performed along the central line of the maze in the treatment room of a Mitsubishi ML-15MIIB medical linear acceleratior (10MV photon mode) located at the National Sapporo Hospital. When measured value was plotted on a logarithmic graph paper against the reduced distance from the mouth of the maze (a ratio of real distance to a diameter of a circle with the same cross section as the rectangular opening, the reduction in the 2nd leg of the maze was able to be fitted to a linear function, and the gradients of -3.00 for neutrons and -3.17 for the X-ray were able to be found. It was also found that this plotting method was excellent to express the dose reduction properties in a maze. Neutron dose distributions over some cross sections of the maze were measured. From the results, it was found that the doses reduced in the direction of the maze barrier, and vertical dose distributions were nearly equal in the area of the height up to 2m. As the measurement location approched to the entrance door, the dose distributions was gradually uniformized over the whole of the cross section. The tendency of above distributions were nearly independent to beam directions. The dose reduction of neutrons by the entrance door (about 3mm thickness steel +6mm thickness lead) was 8.7%. It became clear that the capture of thermal neutrons in iron was the main cause for the dose reduction by the door.
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TAKAKO SHINPO
Article type: Article
1984 Volume 40 Issue 2 Pages
227-230
Published: March 01, 1984
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The hepatic fractional clearance of ^<99m>Tc-Sn-colloids has been used as a measure of effective hepatic blood flow, which is obtained from the disappearance rate multiplied by the fraction of the injected dose taken up by the liver. In this report, we have proposed a new coefficient which is the disappearance rate coefficient and the hepatic uptake coefficient obtained from the Hepatogram using ^<99m>Tc-Sn-colloids. The disappearance rate coefficient was calculated by the initial slope index of the disappearance curve, and the hepatic uptake coefficient was calculated by the initial slope index of the uptake curve. These coefficients were obtained by simply comparing them with the conventional measures. Useful information about hepatic diseases was able to be achieved using these coefficients.
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YOSHIHARU SUKENOBU, MICHIHIRO SASAGAKI, TOMOHIRO ASADA, KAZUYA YAMAGUC ...
Article type: Article
1984 Volume 40 Issue 2 Pages
231-237
Published: March 01, 1984
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One of the most popular evaluation methods of radiographic images is the measurement of modulation transfer function (MTF) using the slit method, which is very useful to compare similar characters of filmscreen systems. However, it is difficult to measure the MTF plainly without a loss in accuracy. So, we connected a microdensitometer to the computer and wrote a computer program which was able to measure the MTF automatically. To reduce the fluctuations and uncertainties in the calculated MTF, we examined the precess from the film scanning by microdensitometer to the MTF calculating by Fourier transformation. We firmly believe that the linearization process is the most important process to reduce MTF fluctuations. As a result of using the SPLINE function (H & D curve approximate expression) in the process of linearization decreases fluctuations and uncertainties of the MTF were able to be when it was included in the manual measurement. We were able to save a great deal of work when we measured the MTF.
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TAKASHI WAKAMATSU
Article type: Article
1984 Volume 40 Issue 2 Pages
238-245
Published: March 01, 1984
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MASAKATSU HATAGAWA
Article type: Article
1984 Volume 40 Issue 2 Pages
246-252
Published: March 01, 1984
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The modulation transfer function (MTF) which is based on the frequency analysis has been widly used for evaluation of sharpness. A theory and measuring method of MTF have been well recognized. However, some problems still remain, such as the accuracy of measurment and the unagreement with the evaluation of image quality. From a practical point of view, the most impotant point is the measuring method of the MTF for screen-film system. In this paper, the auther investigated to those problems and furthermore, discussed the future trends of the MTF.
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HITOSHI KANAMORI
Article type: Article
1984 Volume 40 Issue 2 Pages
253-258
Published: March 01, 1984
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The spectrum (spatial-frequency component) of the information capacity of radiographs is offered for the evaluation of image quality and system performance. We call it the information spectrum. It combines synthetically the contrast, the latitude, the sharpness and the granularity, as a function of spatial frequency. Examples are given. We can select the appropriate system for each object by comparing the information spectra of various imaging systems at the significant spatial frequency range predetermined for each object.
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TAKASHI WAKAMATSU
Article type: Article
1984 Volume 40 Issue 2 Pages
259-265
Published: March 01, 1984
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History of evaluation of radiographic image quality by means of human vision ROC curves is discribed. It is important that radiographic image quality is estimated by both of ROC curves of human vision and physical factors. Our theory consists of detectivity by means of an ideal detector or a real detector which generates the noise itself. Detectivity of a real detector was increased by γ or frequency enhancement images on original radiograph.
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HIROSHI INATSU
Article type: Article
1984 Volume 40 Issue 2 Pages
266-271
Published: March 01, 1984
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The evaluation by means of entropy analysis is a new approach which employs precision of measurement as the synthetic single-parameter descriptor in a nonlinear system. This new approach is widely applied to the psychological and the physical evaluation of radiological imaging systems. In this paper, it is shown that only the transmitted information can be used for absolute measurement of physical image quality. We have also tried to apply transmitted information to the evaluation of contrast resolving power.
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MASAO TAKANO
Article type: Article
1984 Volume 40 Issue 2 Pages
272-277
Published: March 01, 1984
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In the conventional picture quality assessment, analog images have mainly been dealt with. However, as the IC technology has made a great progress, new digital image formation systems are appearing aiming at processing images. Picture quality assessment of these new digital images is studied and the following conclusions are obtained : 1. Even digital images can basically be assessed by the conventional analog image assessment method as long as the system characteristics are taken into account. 2. One the most important subjects in assessing picture quality is not to excessively rely upon "theory" far from clinical data.
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
278-279
Published: March 01, 1984
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HIROSHI IKEDA
Article type: Article
1984 Volume 40 Issue 2 Pages
280-293
Published: March 01, 1984
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Based on the substantial accumulation of recent radiobiological improvements, high LET radiation using nuclear particles has been applied for clinical trials. High LET radiation has the properties of (1) improved dose distributions due to Bragg peak, and (2) reduced repair from sublethal damage and OER. In USA and Canada, neutrons, protons, pi-mesons and heavy particles are being used for clinical trials. Over 2,500 cases have been treated with neutrons until the end of 1981. The results are comparable to those of conventional photons, but not so good as those from Hammersmith Hospital neutron trial. Ocular melanomas are treated with protons at Harvard Cyclotron/MGH with excellent results (local control 93/95). These are attributable to excellent spatial dose distribution and prescise positioning, for protons are not considered as high LET. Pimeson treatment had been conducted at LAMPF from 1974 through 1981 with 230 clinical cases. However, mainly because of the budgetary and locational limitations, it is not operational to date. Radiotherapy of Helium ions and heavy particles are being conducted at Lawrence Berkeley Laboratory. Helium irradiation has yielded significant results, but further compilation and precise evaluation are still needed as to heavy particles. Advantage of high LET will probably be justified with the accumulation of biological and clinical data in the near future.
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AKIHIRO KUSADA, NOBUYUKI AKAMATSU, HIRONOBU OHMURA, KATSUHIKO SEKO
Article type: Article
1984 Volume 40 Issue 2 Pages
294-297
Published: March 01, 1984
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When we consider radiographical technique for the aged, as they make differences it would be better for us to have sympathy and watch carefully against their body and mind. Although we give attention to them inside out, and yet that they are X-rayed is for them a big burden, we have a lot of issues to get rid of it. But we tried to use an air pillow which made of a polyethlene bag, so that……not only they get rid of body's burden, so they have a lot of time to talk each other but also it is possible to reduce mind's burden.
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HISASHI MIYASHITA
Article type: Article
1984 Volume 40 Issue 2 Pages
298-300
Published: March 01, 1984
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The number of the patients of the aged has been remarkably increasing recently. Different from the patients of the adults in general, most of them are in a disadvantageous position for photographing-poor hearing, weak eyesight, trouble in hands and legs, slowness in motion, etc. As this tendency seems to increase more and more in future, equipments, devices and safe plan fit for the tendency are needed to be thought out.
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TOSHIO ENDO, MASAHARU HIROSE, TOMIO AOKI
Article type: Article
1984 Volume 40 Issue 2 Pages
301-304
Published: March 01, 1984
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More than 20 parcent of the emaergency patients transfered to our Medical Center are the critically ill old persons. In addition to the general care of the general care of the critically ill patients, we have to be aware of the special problems of the aged on the radiological examination of these patients. This report deals with our investigations on the development of the X-ray equipment system and the technique suitable to the examination of the old critically ill persons.
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KAZUO AWAI, HIDEAKI TOGI, MASAAKI KAGAWA, TAKASHI WAKAMATSU, KAZUO SUG ...
Article type: Article
1984 Volume 40 Issue 2 Pages
305-308
Published: March 01, 1984
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Senile angiographic examination is difficult to perform because of the involvement of several factors such as meanderling, stenosis and atherogenesis due to arteriosclerosis, depression in renal function and drop in mental understanding. Low aggressiveness and rapid and safe operability of DSA as well as less pains given to patients by DSA, make it very useful for the senile angiographic examination.
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TAKAO KAWATO, JUN-ICHI YAMASHITA, HIDEYO OKUMACHI, MASAAKI HIGASHI, JU ...
Article type: Article
1984 Volume 40 Issue 2 Pages
309-312
Published: March 01, 1984
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In general, the geometric magnification radioangiography has been taken and the large amount of contrast medium has been injected with high speed even for the angiocardiography of old patient. But we think that there are several problems in these techniques for aged patients. So we have studied these methods and got the results as follows ; 1) The different curves of MTF may be got according to the magnification rate and these curves cross with each other-So, the windths of picture have the different values compared to the true it. 2) The good angiographic pictures are got with the slow speed injections of dye even by the low exposure of tube voltage. This method is advantageous for the aged patients who may have the low renal function. We conclude that the geometric magnification radiography shoud not be used too easily and the low exposure of tube voltage with slow speed injection technique may be useful for the angiocardiography of old ages.
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
313-314
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Article type: Appendix
1984 Volume 40 Issue 2 Pages
315-329
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Article type: Appendix
1984 Volume 40 Issue 2 Pages
330-331
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Article type: Appendix
1984 Volume 40 Issue 2 Pages
332-333
Published: March 01, 1984
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
334-
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
334-
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
334-335
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
335-
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[in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
335-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1984 Volume 40 Issue 2 Pages
336-
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
336-
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
336-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
336-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
336-337
Published: March 01, 1984
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
337-
Published: March 01, 1984
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1984 Volume 40 Issue 2 Pages
337-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1984 Volume 40 Issue 2 Pages
337-
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[in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
338-
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[in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
338-
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[in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
338-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1984 Volume 40 Issue 2 Pages
338-339
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
339-
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
339-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
340-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
Article type: Article
1984 Volume 40 Issue 2 Pages
340-
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[in Japanese], [in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
340-
Published: March 01, 1984
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[in Japanese], [in Japanese], [in Japanese]
Article type: Article
1984 Volume 40 Issue 2 Pages
340-
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