A METHOD AND A SYSTEM FOR ENABLING ESTIMATION OF AN INITIAL POINT OF INTERACTION OF AN X-RAY PHOTON IN A PHOTON-COUNTING X-RAY DETECTOR

摘要

There is provided a method for enabling estimation of an initial point of interaction of an x-ray photon in a photon-counting x-ray detector, which is based on a number of x- ray detector sub-modules or wafers, each of which comprises detector elements, wherein the x-ray detector sub-modules are oriented in edge-on geometry with the edge directed towards the x-ray source, assuming the x-rays enter through the edge. Each detector sub-module or wafer has a thickness with two opposite sides of different potentials to enable charge drift towards the side, where the detector elements, also referred to as pixels, are arranged. Basically, the method comprises: determining (S1) an estimate of charge diffusion originating from a Compton interaction or an interaction through photoeffect related to the x-ray photon in a detector sub-module or wafer of the x-ray detector; and estimating (S2) the initial point of interaction along the thickness of the detector sub-module based on the determined estimate of charge diffusion.