RADIATION QUALITIES FOR TESTS IN DIAGNOSTIC-RADIOLOGY

The paper gives an overview on the essential parameters which have to be taken into account for designing radiation qualities suitable for tests in diagnostic radiology. It is divided into two sections the first of which is devoted to fields with small amounts of scattered radiation. These fields can be characterised reasonably well by the terms beam attenuation and beam hardening. The two effects occur always simultaneously with a preference towards attenuation for filtering materials of low atomic number and vice versa. The second part is devoted to fields with abundant scattered radiation. In these cases the field diameter and the distance from the exit surface of the phantom are additional important parameters. Possible sources of errors of measurement in such fields are discussed, some recommendations on their usage are given.