Quantitative molecular imaging with PET can offer insights into physiologic and pathologic processes and is widely used for studying brain disorders. The NeuroEXPLORER is a recently developed dedicated brain PET system offering high spatial resolution and high sensitivity with an extended axial length. This study evaluated the quantitative precision and accuracy of the NeuroEXPLORER with phantom and human data for a variety of imaging conditions that are relevant to dynamic neuroimaging studies. Methods: Thirty-minute scans of an image quality (IQ) phantom and a 3-dimensional Hoffman brain phantom filled with [¹⁸F]FDG were performed over 13 h, covering phantom activities of 1.3–177 MBq. Furthermore, a uniform cylindric phantom filled with 558 MBq of ¹¹C was scanned for 4 h. Quantitative accuracy was assessed using the contrast recovery coefficient (CRC), background variability, and background bias in the IQ phantom, the recovery coefficients (RCs) in the Hoffman phantom, and the bias in the uniform phantom. Results were compared at delayed time points, with different reconstruction parameters and frame lengths down to 1 s. Moreover, randomly subsampled frames of 2 imaging time points (0–2 min and 60–90 min) from a dynamic scan of a healthy volunteer with a 177-MBq injected dose of (R)-4-(3-fluoro-5-(fluoro-¹⁸F)phenyl)-1-((3-methylpyridin-4-yl)methyl)pyrrolidin-2-one ([¹⁸F]SynVesT-1) were used to assess quantification of brain uptake and image-derived input function extraction. Results: Negligible effects were observed on CRC and background bias with 3–177 MBq in the IQ phantom, and bias was less than 5% with 1–558 MBq in the uniform phantom. RC variations were within ±1% with 2–169 MBq in the Hoffman phantom, showcasing the system’s high spatial resolution and high sensitivity. Short-frame reconstructions of the 60- to 90-min healthy-volunteer scan showed a ±1% mean difference in quantification of brain uptake for frame lengths down to 30 s and demonstrated the feasibility of measuring image-derived input function with mean absolute differences below 10% for frame lengths down to 1 s. Conclusion: The NeuroEXPLORER, with its high detection sensitivity, maintains high precision and accuracy across a wide range of imaging conditions beyond those evaluated in standard performance tests. These results demonstrate its potential for quantitative neuroimaging applications.

使用 PET 进行定量分子成像可以深入了解生理和病理过程，并广泛用于研究脑部疾病。NeuroEXPLORER 是最近开发的专用脑部 PET 系统，具有高空间分辨率和高灵敏度，并具有更长的轴向长度。本研究评估了 NeuroEXPLORER 与模型和人体数据在与动态神经影像学研究相关的各种成像条件下的定量精度和准确性。方法：在 13 小时内对图像质量 （IQ） 模型和充满 [¹⁸F]FDG 的 3D Hoffman 脑模型进行了 30 分钟的扫描，涵盖 1.3-177 MBq 的模型活动。此外，对填充 ¹¹C 的 558 MBq 的均匀圆柱形模型进行了 4 小时的扫描。使用 IQ 模型中的对比恢复系数 （CRC）、背景变异性和背景偏差、Hoffman 模型中的恢复系数 （RC） 和均匀模型中的偏差来评估定量准确性。在延迟时间点比较结果，使用不同的重建参数和低至 1 s 的帧长。此外，使用注射 177-MBq 剂量的 （R）-4-（3-氟-5-（氟-¹⁸F）苯基）-1-（（3-甲基吡啶-4-基）甲基）吡咯烷-2-酮 （[¹⁸F]SynVesT-1） 对健康志愿者进行动态扫描的 2 个成像时间点（0-2 分钟和 60-90 分钟）的随机子采样帧用于评估大脑摄取的量化和图像衍生的输入函数提取。结果：在 IQ 模型中观察到 3-177 MBq 对 CRC 和背景偏差的影响可以忽略不计，在均匀模型中观察到 1-558 MBq 的偏差小于 5%。 在 Hoffman 模型中，2–169 MBq 的 RC 变化在 ±1% 以内，展示了该系统的高空间分辨率和高灵敏度。60 至 90 分钟健康志愿者扫描的短帧重建显示，对于低至 30 秒的帧长，大脑摄取的量化平均差异为 ±1%，并证明了测量图像衍生输入函数的可行性，平均绝对差异低于 10%，帧长低至 1 秒。结论：NeuroEXPLORER 具有高检测灵敏度， 在标准性能测试评估之外的各种成像条件下保持高精度和准确度。这些结果证明了它在定量神经成像应用方面的潜力。