Specifies the method for the determination of the detective quantum efficiency (DQE) of digital X-ray imaging devices as a function of air kerma and of spatial frequency for the working conditions in the range of the medical application as specified by the manufacturer. The intended users of this part of IEC 62220 are manufacturers and well equipped test laboratories. This Part 1-2 is restricted to digital X-ray imaging devices that are used for mammographic imaging such as but not exclusively, CR systems, direct and indirect flat panel detector based systems, scanning systems (CCD based or photon-counting). This part of IEC 62220 is not applicable to - digital X-ray imaging devices intended to be used in general radiography or in dental radiography; - computed tomography; and - devices for dynamic imaging (where series of images are acquired, as in fluoroscopic or cardiac imaging).