Performance of automatic exposure controls in mammography

This study describes the phantoms and methods for performance evaluation of 23 phototimers used in mammography. The evaluation is primarily based on an analysis of the optical densities of image receptors (films). According to the results, the kVp compensation, the response capability, the saturation, and the density controls of the phototimers are very poor. The variation in optical film density exceeded +/- 0.3 optical density (OD) in 87% of the phototimers for the tube voltage range 25-40 kVp and for the 2-6-cm-thick phantoms. The operation of the density controls should be adjusted in 70% of the phototimers. Recommendations are presented.