IEC 62220-1-3:2008 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 1-3 is restricted to digital X-ray imaging devices that are used for dynamic imaging such as, but not exclusively, direct and indirect flat panel-detector based systems. It is not recommended to use this part of IEC 62220 for digital X-ray image intensifier-based systems.