This article discusses how to implement PET medical imaging technology using scintillator arrays. It provides a comprehensive overview of the principles of PET medical imaging technology, the working principle of scintillator pixelated arrays in PET technology, and typical scintillator materials suitable for PET medical imaging, namely LYSO (Ce) cerium-doped yttrium lutetium silicate, GAGG (Ce) cerium-doped gadolinium gallium garnet, and the emerging technology of LaBr3 (Ce)-based scintillator arrays, which are suitable for time-of-flight positron emission tomography (TOF-PET).