1. A system for identifying non-functioning pixels in positron emission tomography (PET) imaging, said system comprising: a pixel identification processor configured to: receive data describing scintillation events localized to a plurality of pixels of a PET scanner; generate a count map histogram from the received data, the count map histogram mapping each of the pixels to a count of scintillation events localized to the pixel; and identify one or more non-functioning pixels from the count map histogram.