Abstract: A method for photon counting imaging with improved high-rate counting performance includes the step of applying an instant retrigger capability with adjustable dead time in cells of the detector array and operates an apparatus using a layer of photosensitive material, an L×K array of photodetector elements arranged in the layer of the photosensitive material, an N×M array of readout unit cells, including amplifying elements and at least one readout unit cells for at least one photodetector elements. The readout unit cells are controlled by signal processing elements with each readout unit cell having internal signal processing elements to generate a discriminator output signal representing an amplified signal of the electron-hole pairs generated by an incident photon or a number of incident photons in the respective photodetector element.