Systems and methods include determination of a first relationship between change in photopeak energy and event time skew based on a first detection event signal acquired from a detector at a first temperature and a subsequent detection event signal acquired from the detector at a next temperature, acquisition of a subsequent detection event signal from the detector, determination of an event time associated with this detection event signal, determination of an event time skew based on an energy of this detection event signal and the first relationship, determination of a corrected event time based on the event time and the event time skew, and identification of a coincidence based on the corrected event time.