Abstract
A radiographic mottle is usually evaluated under a given X ray condition such as a tube voltage of 80 kV with 20 mm aluminum filtration. However, it is thought that radiographic mottles of the screen-film system may be influenced by the energy of X rays or the content of scattered radiation. We obtained Wiener spectra under various conditions in which the content of scattered X rays, the X ray tube voltage and the thickness of patient were changed. Several conclusions were able to be drawn from this study : (1) radiographic mottle was slightly improved under the presence of scattered X rays : (2) the magnitude of radiographic mottle decreased as tube voltage increased : (3) the radiographic mottle was almost same even when the thickness of a patient increased.
