Specifies the method for the determination of the detective quantum efficiency (DQE) of digital X-ray imaging devices as a function of exposure and of spatial frequency for the working conditions in the range of the medical application as specified by the manufacturer. Is applicable to projection digital X-ray imaging devices producing images in digital format that are used for medical diagnosis. It is restricted to digital X-ray imaging devices that are used for radiographic imaging, such as CR systems, selenium-based systems, flat panel detectors, optically coupled CCD detectors, and digital X-ray image intensifiers used for single exposures.