Abstract
In fluoroscopy, the best proportion among kVp, mA and FHD is essential for the most effective method of raising the hit rate of fluoroscopy and decreasing useless surface dose. The most important pre-condition is to keep the brightness of the fluorescent screen uniform. Under the absolution value of brightness, 0.05 cp/m^2 for objects, i.e. legs 8 cm thick, the change of X-ray energy corresponding to that of the thickness of the object at the same brightness, was drawn throgh the development factor and this relation was shown in a chart in order to investigate the theoretical grounds of the relation among kVp. mA and FHD. These experimental results were applied to clinical examinations and good results were obtained and reported here.
