Algorithms that Exploit 3-D Positioning PET Detectors to Enhance System Performance
We are investigating high resolution detectors that can record the three-dimensional coordinates, energy, and arrival time of every interaction that an incoming 511 keV photon encounters as it traverses the PET system. Algorithms under development that exploit these unique “3D positioning” capabilities can yield improved image quality and accuracy in PET. For example, we can use this rich information from multiple interactions in the detector material to, in conjunction with new algorithms under study, estimate the incident photon entrance angle with respect to the detector face. Having good incident photon angular resolution enables unprecedented new features in PET such as the ability to accurately position and retain rather than reject single (un-paired) annihilation photons or tissue-scattered photons entering the system, or to extract paired coincident photons from multiple photon (>2) coincidence events that are normally disg\carded. If successful this enables great increases in detected photon statistics compared to the standard PET processing chain that rejects such event types. Photon incidence angle also enables more accurate rejection of “random” coincidence photon background, which yields better image contrast resolution.