Development of Compton-PET hybrid imaging system with CeBr₃-SiPM arrays

Abstract

Positron emission tomography (PET) and single photon emission computed tomography (SPECT) are both established imaging technologies in nuclear medicine that are clinically available. However, simultaneous PET and SPECT nuclide imaging is difficult to accomplish with current equipment because of their distinct principles. In light of this, we have developed and demonstrated a GAGG scintillator based Compton-PET hybrid imaging system capable of performing PET and Compton imaging simultaneously. Alternatively, the CeBr3 scintillator possesses more desirable properties, including a high light yield (>60000 photons/MeV), a fast decay time (∼19 ns), and an excellent energy resolution (<4%@662 keV). Herein, we developed an 8 × 8 array of CeBr3 detector based instrumentation by using 64 channel fast signal processing slew rate limited Time over Threshold (ToT) based application-specific integrated circuits and a field programmable gate array ToT data acquisition system with a 62.5 ps accuracy. Furthermore, we evaluated the system’s basic performances. The mean and greatest energy resolutions were 10.1% and 6.0% (FWHM) for 662 keV. The time resolution was 239 ps (FWHM) after offset calibration. We also achieved a proof-of-concept based on single source.