A new generation of positron emission tomography with computed tomography (PET-CT) was recently introduced using silicon (Si) photomultiplier (PM)-based technology. Our aim was to compare the image quality and diagnostic performance of a SiPM-based PET-CT (Discovery MI; GE Healthcare, Milwaukee, WI, USA) with a time-of-flight PET-CT scanner with a conventional PM detector (Gemini TF; Philips Healthcare, Cleveland, OH, USA), including reconstruction algorithms per vendor’s recommendations. Imaging of the National Electrical Manufacturers Association IEC body phantom and 16 patients was carried out using 1.5 min/bed for the Discovery MI PET-CT and 2 min/bed for the Gemini TF PET-CT. Images were analysed for recovery coefficients for the phantom, signal-to-noise ratio in the liver, standardized uptake values (SUV) in lesions, number of lesions and metabolic TNM classifications in patients. In phantom, the correct (> 90%) activity level was measured for spheres ≥17 mm for Discovery MI, whereas the Gemini TF reached a correct measured activity level for the 37-mm sphere. In patient studies, metabolic TNM classification was worse using images obtained from the Discovery MI compared those obtained from the Gemini TF in 4 of 15 patients. A trend toward more malignant, inflammatory and unclear lesions was found using images acquired with the Discovery MI compared with the Gemini TF, but this was not statistically significant. Lesion-to-blood-pool SUV ratios were significantly higher in images from the Discovery MI compared with the Gemini TF for lesions smaller than 1 cm (p < 0.001), but this was not the case for larger lesions (p = 0.053). The signal-to-noise ratio in the liver was similar between platforms (p = 0.52). Also, shorter acquisition times were possible using the Discovery MI, with preserved signal-to-noise ratio in the liver. Image quality was better with Discovery MI compared to conventional Gemini TF. Although no gold standard was available, the results indicate that the new PET-CT generation will provide potentially better diagnostic performance.

中文翻译：

---

传统 PET 系统与基于硅光电倍增管的 PET 系统的图像质量和诊断性能比较

最近推出了采用硅 (Si) 光电倍增管 (PM) 技术的新一代正电子发射断层扫描计算机断层扫描 (PET-CT)。我们的目的是将基于 SiPM 的 PET-CT（Discovery MI；GE Healthcare，密尔沃基，威斯康星州，美国）与带有传统 PM 探测器（Gemini）的飞行时间 PET-CT 扫描仪的图像质量和诊断性能进行比较TF；Philips Healthcare，克利夫兰，俄亥俄州，美国），包括按照供应商建议的重建算法。对美国电气制造商协会 IEC 人体模型和 16 名患者进行成像，Discovery MI PET-CT 的成像时间为 1.5 分钟/床，Gemini TF PET-CT 的成像时间为 2 分钟/床。分析图像的模型恢复系数、肝脏信噪比、病灶标准化摄取值 (SUV)、病灶数量和患者代谢 TNM 分类。在体模中，对于 Discovery MI ≥17 毫米的球体测量到了正确的 (> 90%) 活动水平，而 Gemini TF 对于 37 毫米的球体达到了正确的测量活动水平。在患者研究中，15 名患者中有 4 名使用从 Discovery MI 获得的图像进行代谢 TNM 分类，而从 Gemini TF 获得的图像与从 Gemini TF 获得的图像相比，代谢 TNM 分类更差。与 Gemini TF 相比，使用 Discovery MI 采集的图像发现了更多恶性、炎症和不明确病变的趋势，但这并不具有统计学意义。对于小于 1 cm 的病变，Discovery MI 图像中的病变与血池 SUV 比率显着高于 Gemini TF (p < 0.001)，但对于较大病变，情况并非如此 (p = 0.053)。不同平台之间肝脏的信噪比相似 (p = 0.52)。此外，使用 Discovery MI 还可以缩短采集时间，同时保留肝脏的信噪比。与传统 Gemini TF 相比，Discovery MI 的图像质量更好。尽管没有可用的黄金标准，但结果表明新一代 PET-CT 将提供潜在的更好的诊断性能。