[en] In order to evaluate the possibility of using computed radiographic mammography in mass surveys of the breast, we have retrospectively examined 71 breast cancer lesions in 71 patients using computed radiographic and conventional non-screen mammographies and have carried out comparative studies on tumor detection rate and calcification. A 95.8% detection rate was obtained for the tumor image (n 71) using computed radiography (CR) and one of 93.0% using non-screen techniques. Three lesions remained undetected by either study. A 100% detection rate was obtained for calcification associated with cancer (n 33) from each method. No significant differences in either detection rate or calcification were seen between the two images. On the other hand, the ability to recognize tumor images (n 66) was as follows; CR superior to non-screen radiography in 53 lesions (80.3%), equal in eight lesions (12.1%) and inferior in five lesions (7.6%). For the calcification images (n 18), CR was superior to non-screen radiography in all 18 lesions. Obviously, CR gives better results than non-screen radiography. Furthermore, an adequate image can be obtained using CR even although the X-ray dosage is only a twentieth of that required for non-screen radiography. It can therefore be applied not only to mass surveys for breast cancer but also to routine clinical diagnoses. (author)

[en] Given growing concerns over global warming problems in recent years, a matter of great importance has been to grasp GHG emissions from fossil energy use as accurately as possible by figuring out how much GHGs result from a life cycle (production, transportation and consumption) of various fossil energies. The objective of this study is to make a life cycle inventory (LCI) analysis of major fossil energies (coal, oil, LNG, LPG) consumed in Japan pursuant to ISO 14040. On these fossil energies imported to Japan in 1997, LCI analysis results of GHG emissions (specifically carbon dioxide and methane) put CO₂ intensity during their combustion stage (gross heat value basis) at 100:121:138:179 among LNG:LPG:oil:coal. But, in life cycle terms, the ratios turned to be 100:110:120:154. The world average (gross heat value basis) gained from IPCC data, among others, puts the ratios among LNG:LPG:oil:coal at 100:105:110:151. In comparison, our study that focused on Japan found their corresponding figures at 100:110:120:154. COP₃ set forth country-by-country targets. Yet, global warming, that is a worldwide problem, also requires a more comprehensive assessment based on a life cycle analysis (LCA). The estimation results of our study can be of some help in shaping some criteria when considering energy and environmental policies from a global viewpoint. In addition, our study results suggest the importance of the best energy mix that is endorsed by LCI analysis results, if global warming abatement efforts should successfully be in advance. As specific institutional designs of Kyoto Mechanism are currently under examination, the introduction of LCI method deserves to be considered in discussing the baseline issue of joint implementation and clean development mechanism. In the days ahead, by gathering and analysing detailed-ever data, and through fossil-energy LCA by use, we had better consider supply and demand of the right energies in the right uses. (author)

[en] Digital radiography for diagnosis of chest diseases using Fuji Computed Radiography (FCR) was evaluated. The results were as follows; 1. Compared to the conventional chest X-ray films, various types of image enhancement could be made by manipulation of the digital information such as tone conversion, spatial frequency modification etc. 2. Digital radiography lessens the X-ray exposure dose and will ultimately permit speedy transmission of image data from outlying clinics to central processing hospitals. 3. Digital radiographic images are useful in chest X-ray diagnosis especially in mass surveys for lung cancer and in primary care medicine because of its full imaging capability. (author)

[en] Three-dimensional (3D) magnetic resonance angiography (MRA) was obtained by means of the 3D Fourier transfer (FT) field echo (FE) technique (repetition time 15∼17 msec, echo time 3∼8 msec, flip angle 15deg, slab thickness 67 mm) in 14 patients with pulmonary nodules during a single breath hold. 3D MRA was evaluated in comparison with the spin echo method. Subsegmental pulmonary arteries were highly definable (78.5%: right lung), and all pulmonary nodules were well identified and had fewer artifacts than images obtained by the spin echo (SE) technique. In conclusion, 3D MRA was found to be a promising method in the assessment of pulmonary nodules with MRI. (author)

[en] Direct measurements of the yield of hydrated electrons in aqueous solutions and solvated electrons in alcohols were carried out using a stroboscopic picosecond pulse radiolysis system. The yield of solvated electrons was obtained by simultaneous consideration of the pulse shape and radiation doses. The yield at 30 ps after irradiation, G(esub(aq)^-)sub(30ps), was determined to be 4.8 +- 0.3 products per 100 eV as compared to the G(esub(aq)^-)sub(100ns) of 2.7. Experimental values, including the present ones, are higher by 0.3 than the theoretical ones calculated using the spur diffusion model in the time period from 3 x 10^-11 to 10^-8 s. Nevertheless, both results show a quite similar time dependence, i.e., fast decay of hydrated electrons in spur reactions. The G-values of solvated electrons at 30 ps were also determined in alcohols. The G-value of solvated electron is 3.4 +- 0.3 in both methanol and ethanol, 2.0 +- 0.3 in 1-propanol and 2.3 +- 0.3 in ethylene glycol. (author)

[en] CR has ability to make many kinds of images by several imaging processings. Especially, gradation processing is more important than frequency processing to make images in CR mammography. We developed new method to image breast masses selectively with new gradation processing and tried it for 18 patients over sixty years old with breast cancer. All of breast mass shadows were separated selectively from other parencymal shadow. So, we conclude that the auto-recognition of breast mass shadow can be possible in near future in CR system. (author)

[en] sup(99m)Tc-phytate liver scan and percutaneous transhepatic portography (PTP) were performed in 33 patients with portal hypertension due to various hepatic diseases. A defect or space occupying lesion in the left lobe on the scan in these patients was analysed with reference to portographic changes of the pars umbilicus of the left portal vein and the following results were obtained. 1) A false-positive defect on the scintigram was found in 6 (18.2%) of 33 patients, and portal vein pressure (PVP) was above 200 mmH₂O in all 6 which constituted 21.4% of 28 with PVP above 200 mmH₂O. 2) In five out of 6 patients with false-positive scan findings, the pars umbilicus was dilated to more than 25 x 15 mm in size, and it was huge and tortuous in 3 of them. 3) The mean PVP in the group with a false-positive scan tended to be higher than that in patients with no abnormalities on the scintigram. It was concluded that in reading of liver scintigrams in patients with portal hypertension, a dilated pars umbilicus and huge para-umbilical vein should be considered. (author)

[en] At Rokkasho Reprocessing Plant (RRP), efforts are made so that troubles occurred are promptly reported and announced publicly, and for minor troubles, etc., announcement to the society is made through the web-site and publicity magazines, so as to assure the transparency of the business. (author)

[en] The diagnostic value of the tomogram of digital radiography (CR tomogram) was evaluated in comparison with that of the xerotomogram in 33 patients with small peripheral-type lung lesions, including 22 who were operated on. The margin of the lesions, pleural retraction, involved bronchi, involved vessels, cavity formations and other abnormalities were as clearly visualized by CR tomography as by xerotomography. The thickness of the third or fourth order bronchi could also be observed on the CR tomogram. The CR tomogram proved to be of as much value as the xerotomogram for the diagnostic delineation of the features of peripheral-type lung lesions. (author)

[en] Transient species produced in neat butylchloride and butylbromide were observed by means of picosecond pulse radiolysis. The visible band which was produced during electron pulse and then decayed with a half lifetime of 2 ns was assigned to a vibrationally excited cation. (author)