[Experiences in the testing of standard data on roentgen diagnostic equipment].

The TUV (German Standards Control Body) are performing inspections of standard characteristics of different devices for medical diagnostic radiology used in medical consulting as well as in hospitals. The inspections are carried out according to the recommendations of the German rule "Richtlinien über die Aufzeichnungen nach # 29 der Röntgenverordnung-RöV" (i.e. guide line on recording according to # 29 RöV). In addition the surface dose is measured, which is a characteristic of an x-ray equipment and the knowledge of which is helpful when estimating the patient's radiation exposure. The latter inspections are performed for different modes of operation. In this paper the inspection procedure as well as the results of the inspections of radioscopy and of radiography equipment are presented and discussed. These inspections may be regarded as a part of a general performance test aimed at quality assurance in medical diagnostic radiology. The results show a wide statistical variation of several inspected parameters (e.g. film exposure, exposure rate of the image intensifier). The possible causes of this variation are presented. A further result of the inspections is the fact that in many cases some components of the complete imaging system are unrecognisedly defective. For this reason the inspection records contain-if necessary-recommendations for the improvement of the quality of the image and radiation protection.