The performance of a wide range of digital mammography systems has been compared in terms of the dose required to achieve the image quality standards in the European guidelines at different detail sizes. This paper considers how these results relate to measurements of detector performance on these systems. The dose to meet the minimum requirements in European Guidelines was found to be strongly related to the DQE of the detector systems. Thus where a system has a relatively low DQE at high spatial frequencies (e.g. 5 cycles per mn) a relatively large dose is required to meet the minimum image quality level in European Guidelines for the smallest detail size (i.e. 0.1 mm). The systems showed a very wide range in performance.