Preliminary Results of the Performance Characteristics for the New Digital uMI Panvivo PET/CT System

The newly developed uMI Panvivo PET/CT system utilizes a SiPM- and ASIC-readout-based uExcel UDP detector platform. The integration of application-specific integrated circuit has notably enhanced the system’s counting performance and improved quantitative accuracy in various applications. This study evaluates the performance of the first uMI Panvivo prototype in accordance with the NEMA NU 2-2018 standard. The PET system demonstrates a transaxial spatial resolution of 2.81 mm at full width at half maximum with a 1.0 cm offset from the center, a sensitivity of $16.9 \mathrm{cps} / \mathrm{kBq}$ at the center of the field-of-view, a peak NECR of 366.14 kcps at 37.04 $\mathrm{kBq} / \mathrm{cc}$, and a maximum relative count rate error of less than 4% across all slices for activity concentrations at or below the NECR peak activity. Furthermore, the timing resolution at peak and $5.3 \mathrm{kBq} / \mathrm{ml}$ were 234 ps and 224 ps, respectively. The overall image contrast assessed with the NEMA image quality (NEMA-IQ) phantom ranges from 65.3% to 93.7%, while the background variability ranges from 4.5% to 1.5%. Phantom imaging results suggest that the system exhibits a uniform distribution of background noise.