A study on CZT and scintillator based micro-PETs with Compton Tracing Technology

In this research, we compared the performance of a CZT Compton PET and those of conventional micro-PETs using scintillators in which Compton tracing technology was applied. The conventional micro-PETs used photoelectric interaction only as effective events for PET image reconstruction and their position resolution are limited by the size of a single scintillator voxel. The CZT Compton PET, however, was made of CdZnTe semiconductor which showed high energy and position resolution. In addition, in the case of pixellized CZT detector, the interaction sequence inside the detector can be identified effectively and hence not only photoelectric but also Compton scattering interaction can be useful events for PET image reconstruction. At 511 keV, the probability of Compton scattering is approximately three times larger than that of photoelectric events, which results in high detection efficiency and improved reconstruction image. Based on the detection efficiency and reconstructed image, the performances of PET systems were compared with each other.