Performance Characteristics of CZT Detectors for PET Imaging Applications

Positron emission tomography (PET) is a non-invasive, in-vivo imaging technology that plays a critical role in cancer detection, as well as in molecular and cellular imaging. For PET imaging, Cadmium Zinc Telluride (CZT) detector emerges as a promising alternative to a scintillator and photomultiplier (PMT) detector assembly. In this work, we developed an analytical model to study electron transport, charge collection, signal formation and temporal behavior within a CZT detector. The study is designed to help us optimize a number of detector design parameters including anode/cathode electrode pitch, steering electrode pitch and voltage bias. The performances of a 20×20×5 mm3 pixelated CZT detector were evaluated to demonstrate good energy resolution of ~2.98 ± 0.26% at 511 keV without significant charge sharing effect.