X-ray image sharpening by coincidence detection

In this paper we propose methods to realize coincidence detection in direct or indirect X-ray detectors. This coincidence is used to enhance the image sharpness. Introduction The Medipix collaboration [1] explored the possibility of using the information of multiple pixels detecting the same particle simultaneously. They demonstrated that the accumulated charge of a multiplicity of pixels can be combined to recover the particle’s total ionization charge. Key in this operation is the detection of “coincidence”, i.e. of hits that happen at the same moment in neighboring pixels due to the same event. In X-ray imaging recovering the accumulated charge as such is in most cases not of interest. However there is an added value in the recovery of the loss of image sharpness that occurs due to the fact that the visible light flash caused by an X-photon in a scintillator spreads over multiple pixels (Figure 1). X-ray photon Visible light scintillator P iel sign al Silicon Figure 1 schematic cross section of a Silicon pixel array covered with an X-ray scintillator. A primary X-ray photon generates a flash of secondary visible light in the Scintillator. Pixel 1