An apparatus for low dose mammography including:(1) a monochromatic X-ray beam generator that emits a first beam of monochromatic line emission X-ray photons having an energy at or nearly above an absorption edge of a first element to induce emission of Auger electrons when the first element is irradiated with the X-ray photons； and(2) an X-ray detector including(a) a pixel or plurality of pixels including an array of pixel sensors each of which has (i) a direct conversion layer configured for receiving the X-ray photons and for converting the X-ray photons into a transient electric charge, the direct conversion layer comprising the first element such that the line emission X-ray photons causes a cascade of Auger electrons that form the transient electric charge, and (ii) a semiconductor collection layer configured for receiving Auger electrons of said electric charge from the conversion layer； and(b) processing electronics for converting the electric charge received in the collection layer into a radiographic signal. Also, a method for using the apparatus for low dose mammography.
