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Volume 44, Issue 11
Displaying 1-22 of 22 articles from this issue
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Article type: Cover
1988 Volume 44 Issue 11 Pages Cover5-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Index
1988 Volume 44 Issue 11 Pages Toc5-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Index
1988 Volume 44 Issue 11 Pages Toc6-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Appendix
1988 Volume 44 Issue 11 Pages i-vii
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Appendix
1988 Volume 44 Issue 11 Pages viii-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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OSAMU NAKAMURA, SABURO AKIYAMA, YOSHITOMO SANO, TAKAO ARAI, GUIO UCHIY ...Article type: Article
1988 Volume 44 Issue 11 Pages 1568-1574
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSMagnetic shielding is more difficult than radio frequency shielding. Therefore, good shielding effect can hardly be expected using the magnetic shielding method. This fact can easily be seen by comparing the ratio of energy conduction and the stopping power of electric energy and of magnetic energy. For the study of the magnetic shielding effect of an MRI room, measurements of magnetic field strength were made using gaussmeter equipped with a probe. Furthermore, these results were compared with the results of a computer simulation based on the boundary element method. The experimentally obtained results indicated 33 dB, which corresponds to the attenuation of 1/50. Calculated shielding effect by computer simulation was 20.9 dB, which corresponds to an attenuation of about 1/10.View full abstractDownload PDF (616K) -
SUGUHA TSUTSUMI, MASAKI ABE, TAKEO SOMEYA, NORIKO FUDAGAWAArticle type: Article
1988 Volume 44 Issue 11 Pages 1575-1582
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSThe orthochromatic films have been used in Japan since Eastman Kodak Company introduced the first orthochromatic film "OG" in 1975. We present some results on the evaluation of the film from user's view point on poor silver containing films. The following three results were used for evaluation, namely, 1) the silver content in X-ray films, 2) the characteristic curves of films, and 3) the relationship between the amount of the silver content weight and film characteristics. A flame atomic absorption spectophotometer was used to measure absorbance at 328.0nm. The amounts of silver in X-ray films were studied by measuring various types of films. The "old" regular type films have greater silver weight than "new" type orthochromatic films. From the relationship between silver reduction and film characteristics, we assumed that there was a technical innovation which achieved silver reduction in many orthochromatic films. Though we did not evaluate the image quality of old regular films at this time, we are afraid if there is a trend that such systems decrease flexibility gradually in a long period of time.View full abstractDownload PDF (608K) -
NOBUO SATO, TOSHIHIRO OGURAArticle type: Article
1988 Volume 44 Issue 11 Pages 1583-1591
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSRisk of mammography should be evaluated by the totally absorbed dose into the mammary gland, which is the point of origination of mammary carcinoma. Using a minute anthracene detector immersed in an alcohol/ water mixture, the gland dose was obtained and represented against beam quality (first half-value layer in aluminum) so that it can be presumed from in-air exposure required per view. This study reveals that even if the beam quality of the entrance x-rays is equal for the molybdenum and tungstenum anode x-ray tubes, this does not hold true at each depth of the breasts. The gland dose is around 1/5, for film mammography of the in-air exposure, and is less dependent on age and beam quality compared to skin dose. These results support the use of mammography even for periodic mammary surveys, and also imply that high-sensitivity imaging systems are called for rather than attempting to reduce patient dose by relying on harder beam technique.View full abstractDownload PDF (766K) -
KUNIAKI ISHIZAKI, TAKASHI SUGIYAMA, KATSUO FUNABASHI, KIKUO FUJINAMI, ...Article type: Article
1988 Volume 44 Issue 11 Pages 1592-1597
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSBuild-down effects in water equivalent phantoms and depth dose curves in inhomogeneous phantoms were measured with thermoluminecent dosimeters (TLDs). The kind of TLDs Was CaSO_4 : Tm foil type, and its thickness and diameter were 0.06 mm and 8 mm, respectively. As a result, minute changes in the depth dose in inhomogeneous phantoms were evaluated, and the exit plane was more than the entrance plane for the surface dose. We obtained identical same clinical results in radiotherapy in which the skin reaction was harder on the exit plane.View full abstractDownload PDF (633K) -
TOSHIKI ADACHI, YOSHIHIRO KOZAKURA, ISAMU KATO, YOSHIO YAMAMOTOArticle type: Article
1988 Volume 44 Issue 11 Pages 1598-1601
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESS127 normal values of spinal trabecular bone mineral content (BMC) for 67 males (age range : 20〜77) and 60 females (age range : 23〜76) were studied by quantitative computed tomography (QCT). We have measured L1, L2 and L3 vertebrae, but there is no signifcant difference between L1, L2 and L3 BMC, so we caliculated the individual BMC from the average of the three vertebrae data. The BMC value was found to be greatly enfluenced by age. Its maximum at the age of 20 years for males and females, and decreases gradually with an increase in age with a much more reduction seen in the females. The mean value of BMC for the males was approximately 171 mg/ml K_2HPO_4 equivalent to the 20-40 age range years and the females was approximately 183 mg/ml, so that by the age 70, the males were reduced by 35% to approximately 110 mg/ml, the females were reduced by 50% to approximately 92 mg/ml. The interrelation was analyzed by using a cubic regression study which revealed an adequate correlation (r=0.77 in the males, r=0.85 in the females) between BMC and age.View full abstractDownload PDF (699K) -
HIDEKI KATOArticle type: Article
1988 Volume 44 Issue 11 Pages 1602-1605
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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KAZUYA YAMASHITAArticle type: Article
1988 Volume 44 Issue 11 Pages 1606-1618
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSThis paper is a study radiological technology from the standpoint of social science. A few stadies have been added on medicin and medical care as well. While various definitions of technology exist throughout history, studies were made here from the standpoint of philosophy, natural science and social science, respectively. Due to the uniqueness of medicine and medical care, definition of productive technology does not necessarily apply as it is. Therefore, efforts were made to define medical care technology with maximum interest on this point, and definition of radiological technology was made according to this approach. It was defined as : "Combination and connection of means (apparatuses, machinery, equipments etc.) that have been created because of the necessity to realize the goal pursued by radiologic-medical care, based on experience and knowledge (skille and intelleet) obtained by people involved in medical care." In addition, it revealed that research on radiological technology is a great science that pursues radiation technology and that its development will lead to the development of radiologic-medical care. Furthermore, studies were made on skill, ability and technique.View full abstractDownload PDF (1794K) -
KOSUKE KANDAArticle type: Article
1988 Volume 44 Issue 11 Pages 1619-1625
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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YUTAKA NISHIWAKIArticle type: Article
1988 Volume 44 Issue 11 Pages 1626-1629
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSProblems about obtaining information from chest film in cases where lung cancer is being examined. Lung cancer gives a poor prognosis, even in cases where a curative resection is carried. Good quality chest film is essential for the early detection of lung cancer. The lungs have intricate pulmonary arteries and veins, mingled together with bronchi like a labyrinth for a depth of 20 cm, and they are also surrounded by bones and soft tissue. As these are superimposed on the lungs on the chest film, it is important that their effect on chest film be minimized. Minute densities, which might not be of significance in other organs, have to be clearly shown on chest film.View full abstractDownload PDF (1281K) -
HIROHARU OKADA, KIMIO USAMI, KOUJI YAMADA, YUICHI KURAMATA, HIDEKAZU N ...Article type: Article
1988 Volume 44 Issue 11 Pages 1630-1638
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSChest is a wide dynamic range object composed complex and colorful organs. Therefore, in radiograph of the chest, if is difficult to describe the lung and mediastinum at the proper density on one sheet of film. We have divided it into three cases: film density, tube voltage region and the scatter medium, and introduced NEQ (u) , detectability, spectral SNR as an overall image quality evaluation, and studied application for chest radiography. We obtained the results in which the application of the speed compensating screen is superior to that of density compensating filter or wide latitude film. We realized the situation of directions and energy on scatter X-ray by the Monte-Carlo simulation. In addition, the applicatability of a high density grid was proved using chest radiography.View full abstractDownload PDF (913K) -
SHIGERU MIYAZAKIArticle type: Article
1988 Volume 44 Issue 11 Pages 1639-1649
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSIn clinical chest X-ray radiography, it is generally accepted that a clear X-ray visualization of the lung field requires a short exposure time of 50 msec to avoid any distortion due to cardiac movement and high voltage for X-rays to penetrate organs with different levels of absorption such as the heart and rib to image lung. This study evaluated the capacity and reliability of X-ray generators for such requirements from the response of generator, output of X-ray and photographic effect, by measuring X-ray tube voltage, current, fluorescence and their wave forms. X-ray generators evaluated in the present study were (1) single phase 2-peak generator (2) 3-phase and 12-peak generator (3) constant voltage and capacitor discharge generator, which are widely applied to clinical chest X-ray radiography. The three main points, i.e., (1) X-ray generator (2) optimum exposure time against cardiac movement and (3) automatic density control system, are discussed in this report. Results showed that X-ray output ratios due to the differences in high voltage rectification circuit were 50% in the single phase type generator, and 95% in the 3-phase-type generator compared with the constant-voltage-type generator. X-ray qualities of the single phase type generator and the 3-phase-type generator were approximately 10 kV and a few kV softer compared with that of the constant-voltage-type generator, respectively. The reliability of the generator was confirmed evaluating from their quality variation indexes which were 0-0.05. These values were much lower compared with the JIS index, i. e., 0.1. In conclusion, the most suitable X-ray generator for clinical chest X-ray radiography which requires short exposure time in practice, is the constant-voltage, 3-phase and capacitor discharge generator for its flexibility regarding exposure time and large X-ray output. The most suitable exposure time was concluded to be less than 40 msec. The phototimer, which provides high reliability, is considered to be also applicable for clinical radiography with the appropriate technique.View full abstractDownload PDF (1068K) -
MASAO AOKI, KOJI SUGIKI, KOZO ICHIJOArticle type: Article
1988 Volume 44 Issue 11 Pages 1650-1657
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
JOURNAL FREE ACCESSFor the optimization of image quality of the lung field, detection experiment of simulated tiny lung cancers and evaluation of clinical chest films were carried out, and these results were analyzed by making a comparison with the physical image characteristics. Detectability of shadows simulating tiny lung cancers against the background of lung field varies hardly in spite of depreciation of image characteristics (sharpness and granularity), as far as we use common screens and films, with high voltage technique. However with the low contrast system, a little deterioration of detectability was observed. With any systems, if the diameter of the shadows are 10 mm, detectability falls sharply compared with 12.5 mm. Judgments on clinical films by doctors show that poor graininess is the dominant cause affecting diagnostic utilities and secondly too low or too high contrast. Contrast coefficient (C) is defined. C=μ・(P/P+S)・G where μ=linear attenuation coefficient of primary x-ray reaching intensifying screens (mm^<-1>) P=primary x-ray fraction S=scatter x-ray fraction G=film contrast Adequate range of (C) is from 0.03 to a little over 0.04 (mm^<-1>). Keeping (C) in this range, by using a suitable combination of x-ray energy, anti-scatter grid and film contrast, it is reasonable to try for a better description of the mediastinal zone.View full abstractDownload PDF (975K) -
[in Japanese]Article type: Article
1988 Volume 44 Issue 11 Pages 1658-1661
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Appendix
1988 Volume 44 Issue 11 Pages 1662-1664
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Appendix
1988 Volume 44 Issue 11 Pages 1665-1667
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Appendix
1988 Volume 44 Issue 11 Pages App4-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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Article type: Cover
1988 Volume 44 Issue 11 Pages Cover6-
Published: November 01, 1988
Released on J-STAGE: June 28, 2017
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