Basic quality parameters of x-ray diagnostic equipments

a particularly difficult problem to set up a system of quantitative criteria for image quality and for the related devices. It is a part of the more general complicated problem of quality evaluation for photographic, optical, and optoelectronic forms of imaging. Considerable advances have been made in this area recently [3]. The quality characteristics of an x-ray image and the corresponding characteristics of the generating system can be divided into several groups. The first includes characteristics governing the visibility of small and low-contrast details. The most general of these is @ the signal-to-noise or the contrast-to-granularity ratio. The larger this ratio, the greater the probability that the image of a detail (signal) will be detected against the granular background (noise background).