Requirements of Scintillation Crystals with the Development of PET Scanners

Positron emission tomography (PET) is widely used in the diagnosis of tumors, cardiovascular system diseases, and neurological diseases. Scintillation crystals are an important part of PET scanners; they can convert γ photons into fluorescent photons to obtain their energy, time, and position information. Currently, an important research goal in PET is to find scintillation crystals with better performance. In this work, the principle of scintillation crystals is introduced, and the properties and requirements of scintillation crystals in different PET scanners are analyzed. At present, Lu2(1−x)Y2xSiO5 (LYSO) is the scintillation crystal with the best comprehensive properties. LaBr3 performs even better regarding the timing characteristics and light output; however, LaBr3 has not been used in any PET scanner because of its deliquescence. Detectors made of Gd3(Ga, Al)5O12 (GAGG) exhibit a high depth of interaction (DOI) resolution and have considerable application potential. The application fields of PET are constantly expanding, and its future development aims to achieve high spatial resolution and high sensitivity, which require scintillation crystals with better performance.