Automatic X-ray film processors have been put to a remarkably wide use during the last few years. However, to obtain full performance of an automatic X-ray film processor, it is necessary not only to keep the device itself in adequate mechanical maintenance but also to properly control the processing solutions. To the best of our knowledge, while there is practically no problem on the former, there appears to be a tendency to disrigard the latter. We have studied the control of a developer and fixer to be used with an automatic X-ray film processor, namely, performance of the solutions, fatigue process, limits of processing capacity, methods of maintaing effectivenes, etc., and, on the basis of the results obtained, have established an applieable routine control method. With a view to further increase the efficiency of we examined each of the factors considered adverse to the control. The principal parts of this study are being contributed, as a serial of Report 1 to 7,to a Japanese journal "Fuji X-Ray Report". Comparison between before and after the establishment of the central has shown the following : 1) As the developing capacity of solution bas become generally constant, X-ray photographing conditions are now comparatively easy to set up. 2) Actual X-ray films have become generally uniform in density and tone. 3) Processing capacity of a developer used has increased by as much as four times or so of the figure designated by its manufacturer, resulting in some reduction of cost. 4) It has become passible to clearly see any irregularity in a processing solution. From the foregoing, we keenly feel that, as long as an automatic X-ray processor is employed, it is ihdispensable to control the solutions therefor and to have available a standard exposurer, density meter, etc. required for the control.
The factors which are reported to cause the uneven density of roentgenogram are 1) geometrical condition, 2) sensitive material and procedures of development, 3) effect of scattering X-rays and 4) individual difference in the subjects to be photographed. By improving these difficuties to attain uniform density, the progress can be expected in the application of X-ray to wider ranges of diagnoses. For this purpose, teleroentgenography, use of low gamma film the selection of developer and use of the compensatory intensifying screen or a rectifying filter, etc. have been attempted. We have also developed a movable rectifying filter. We reported on the factors producing uneven density of roentgenogram and on the method to improve it.
The author studied an error of numerical value in measurement with fluoro glass dosimeter. The fluoro glass dosimeter. The fluoro glass used in this study was FD-R1-1 (Toshiba) and had a diameter of 1mm and a length of 6mm. The fluorh meter was FGD-3B (Toshiba). The author applied electron beam of Betatron to the fluoro glass dosimeter in a phantom made of acrylite. The fluctuation of the numerical value of the fluoro meter in a short time was about ±0.15R ; the error of the numerical value, which was probably due to the play of the apparatus, was about 1.56%. The response of the fluoro glass showed a good linearity, extending 1-10^3R of the fluorescence ; the fluorescence of the back ground of the fluoro glass was about 0.7±0.07R (O/x=10%). In this experiment, the author studied also the response of the fluoro glass, using about 100 fluoro glasses. The result was as follows ; Fluorescence The standard deviation in the response [table] It may be said through the comparative study over foreign literature that these numerical value showed better efficiency of this fluoro glass dosimeter the that of foreign ones. The fading of the fluorescence reaches to 5% in 100days and the value of the fading is apot to be divided. The fading is caused also by repeating the measurement of the fluorescence. The author made a futher examination on the error in the measurement with fluoro glass dosimeter through these results mentioned above and other literatures.
Today the abdominal aortography is carried out by method of translumbar and percutaneous transfemoral retrograde catherer. We have practiced the intravenous angio-cardiography as one of the X-ray examination for the heart. Recently the contrast medium is remarkable developed in safety and ability of contrast, then it is even possible that we inject 50-100cc of quantity of the contrast media into the vein of patient. By the same technique of the intravenous A.C.G, using the contrast media at rate of 2cc per Kg of patient's weight, we could get easily useful Radiographies of a series of the abdominal aorta without defferent arterial hazard, for example, the hematoma, the arterial damage, the hemorrhage and other arterial trouble, with only retative light ill effects of contrast media, for instance, the light nausea. We could study about timing of exposure for the many abdominal aortographes by intravenous method, and get them as follow. 1) The starting Time of exposure (T) intravenous method is expected from the patients pulse rate (P). T≒-0.1P+17.8 (sec) 2) If we use the number of heart pulses as the time unit, we constantly get the starting time of exposure for aortography at 12th pulse after the injection of contrast media to the arm vein. 3) It is always necessary for the case of the abnormal heart that the arm-tongue circulation time is measured with saccarin liquid. Because the A-T circulation time corresponds with the time at peak opaque by contrast media about the chest aorta, then we can know from A-T circulation time that the starting time of of exposure for the abdominal aortography is 2-3 pulses before A-T circulation time. (a time unit is a pulse of heart.)
The grid ratio is used for expression of the quality of the grid. The scatter radiation was measured with the water phantom of 10cm thick which represented the chest of the human body of 20cm in thickness. By means of this phantom the Bucky factor, selectivity and contrast improvement factor was measured and discussed for various kinds of the grid with different grid ratio. As a result it was concluded that the grids of the ration in 12 : 1 was most suitable for 120kVp X-rays while that in 6 : 1 sor 70 and 90kVp X-rays.
We determine Half value layer (H.V.L.) by same measurement in diagnostic and therapeutic X-ray tube voltage. It is wrong because H.V.L. change by geometry of measurement. We select geometry H.V.L. dose not change with diagnostic X-ray tube voltage and we found the H.V.L. measurement is better focusfilter distance 20cm, filter chamber distance 30cm for 50kVp and 40cm for 90,130kVp.