Reduction of image artifacts caused by unwanted photons

摘要

A system for recording fewer of the events that are caused either by Compton scatter photons or by gamma radiation interacting with lead. The system locally determines the energy spectrum and fits the determined energy spectrum with a trial function composed of a photopeak component of known energy shape, but unknown magnitude and a Compton scatter component having a theoretically derived energy shape and an unknown magnitude for each pixel of the image. The trial function is locally fitted to the measured energy spectrum to obtain the values of both the Compton Coefficient and the gamma radiation interacting with lead. This enables removal of Compton contamination and also the contamination caused by interaction of the gamma photons with lead components.