PT  - JOURNAL ARTICLE
AU  - Li, Guiyu
AU  - Ma, Wenhui
AU  - Li, Xiang
AU  - Yang, Weidong
AU  - Quan, Zhiyong
AU  - Ma, Taoqi
AU  - Wang, Junling
AU  - Wang, Yunya
AU  - Kang, Fei
AU  - Wang, Jing
TI  - Performance Evaluation of the uMI Panorama PET/CT System in Accordance with the National Electrical Manufacturers Association NU 2-2018 Standard
AID  - 10.2967/jnumed.123.265929
DP  - 2024 Apr 01
TA  - Journal of Nuclear Medicine
PG  - 652--658
VI  - 65
IP  - 4
4099  - http://jnm.snmjournals.org/content/65/4/652.short
4100  - http://jnm.snmjournals.org/content/65/4/652.full
SO  - J Nucl Med2024 Apr 01; 65
AB  - The uMI Panorama is a novel PET/CT system using silicon photomultiplier and application-specific integrated circuit technologies and providing exceptional spatial and time-of-flight (TOF) resolutions. The objective of this study was to assess the physical performance of the uMI Panorama in accordance with the National Electrical Manufacturers Association (NEMA) NU 2-2018 standard. Methods: Spatial resolution, sensitivity, count rate performance, accuracy, image quality, and TOF resolution were evaluated in accordance with the guidelines outlined in the NEMA NU 2-2018 standard. Energy resolution was determined using the same dataset acquired for the count rate performance evaluation. Images from a Hoffman brain phantom, a mini-Derenzo phantom, and 3 patient studies were evaluated to demonstrate system performance. Results: The transaxial spatial resolution at full width at half maximum was measured as 2.88 mm with a 1-cm offset from the center axial field of view. The sensitivity at the center axial field of view was 20.1 kcps/MBq. At an activity concentration of 73.0 kBq/mL, the peak noise-equivalent count rate (NECR) reached 576 kcps with a scatter fraction of approximately 33.2%. For activity concentrations at or below the peak NECR, the maximum relative count rate error among all slices remained consistently below 3%. When assessed using the NEMA image quality phantom, overall image contrast recovery ranged from 63.2% to 88.4%, whereas background variability ranged from 4.2% to 1.1%. TOF resolution was 189 ps at 5.3 kBq/mL and was consistently lower than 200 ps for activity concentrations at or below the peak NECR. The patient studies demonstrated that scans at 2 min/bed produced images characterized by low noise and high contrast. Clear delineation of nuclei, spinal cords, and other substructures of the brain was observed in the brain PET images. Conclusion: uMI Panorama, the world’s first commercial PET system with sub–200-ps TOF resolution, demonstrated fine spatial and fast TOF resolutions, robust count rate performance, and high quantification accuracy across a wide range of activity levels. This advanced technology offers enhanced diagnostic capability for detecting small and low-contrast lesions while showing promising potential under high-count-rate imaging scenarios.