The simulation and reconstruction of mixed detector cylinder PET system

Spatial resolution of a PET system depends on the size of crystal to some extent. In general, the smaller the size of each crystal, the higher the spatial resolution of the PET system. The problem is that with the crystal size becomes smaller, more electronic channels will be needed and the cost of the PET system will increase. Besides, sometimes when imaging some organ like bladder, high spatial resolution is not that necessary. To fix these problems, here we put forward a new method that combines the high spatial resolution crystal with the normal spatial resolution crystal to construct a novel mixed detector module and then we used this module to construct a cylinder PET system. One part used small-size crystals and another part used normal-size crystals in this detector module. Inspired by this method, we can combine high resolution detector module with existing PET machine to construct a mixed detector PET system very quickly. The results demonstrated that these kind of mixed detector cylinder PET system had a good combination of this two kinds of crystals, and we can get different quality reconstruction image by adjusting the position of the target.