A proposal is worked out to express x-ray image quality by means of a meaningful and practically useful numerical system. Attennations have been selected in such a manner that whole numbers of Quality Value figures ranging from -10 to +60 result in meaningful associations with radiological indications. Individual parameters are incorporated into the resulting values. A test body for determining Information Sensitivity figures is described that is practical easy built and inexpensive; its most important feature, however, is that it is reproducible and permits international comparisons. This test body provides a direct linking with the Quality Value figures.