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.

uMI Panorama 是一种新型 PET/CT 系统，采用硅光电倍增管和专用集成电路技术，可提供卓越的空间和飞行时间 (TOF) 分辨率。本研究的目的是根据美国电气制造商协会 (NEMA) NU 2-2018 标准评估 uMI Panorama 的物理性能。方法：根据 NEMA NU 2-2018 标准中概述的指南评估空间分辨率、灵敏度、计数率性能、准确性、图像质量和 TOF 分辨率。使用为计数率性能评估获取的相同数据集确定能量分辨率。对来自 Hoffman 大脑模型、迷你 Derenzo 模型和 3 名患者研究的图像进行了评估，以证明系统性能。结果：半峰全宽处的跨轴空间分辨率测量为 2.88 毫米，与中心轴向视场偏移 1 厘米。中心轴向视场的灵敏度为20.1 kcps/MBq。在活性浓度为 73.0 kBq/mL 时，峰值噪声当量计数率 (NECR) 达到 576 kcps，散射分数约为 33.2%。对于等于或低于 NECR 峰值的活性浓度，所有切片之间的最大相对计数率误差始终保持在 3% 以下。当使用 NEMA 图像质量模型进行评估时，整体图像对比度恢复范围为 63.2% 至 88.4%，而背景变异范围为 4.2% 至 1.1%。 TOF 分辨率在 5.3 kBq/mL 时为 189 ps，并且在活性浓度等于或低于峰值 NECR 时始终低于 200 ps。患者研究表明，每床 2 分钟的扫描产生的图像具有低噪声和高对比度的特点。在大脑 PET 图像中观察到细胞核、脊髓和其他大脑亚结构的清晰轮廓。结论： uMI Panorama 是世界上第一个具有低于 200 ps TOF 分辨率的商用 PET 系统，表现出精细的空间和快速的 TOF 分辨率、强大的计数率性能以及在各种活动水平范围内的高定量准确性。这项先进技术提供了增强的诊断能力，用于检测小的和低对比度的病变，同时在高计数率成像场景下显示出良好的潜力。