系统地研究 [13N]NH3 在器官中的动力学指标和代谢捕获。11 名参与者进行了全身 [13N]NH3 动态正电子发射断层扫描 (PET)。在器官中绘制感兴趣区域以获得活动时间曲线 (TAC)，将其与不可逆双组织室模型 (2TC) 拟合以研究恒定速率 K1、k2 和 k3，并计算 Ki。此外，使用完整数据 (1TCfull) 和前四分钟数据 (1TC4min) 的单组织室模型适合 TAC 数据。比较不同模型之间的 K1 和 k2，以评估[13N]NH3 在器官中的捕获。[13N]NH3 的动力学速率在器官之间存在显着差异。平均 K1 范围从肌肉中的 0.049 mL/cm3/min 到肾脏中的 2.936 mL/cm3/min。 k2 和 k3 在肝脏 (0.001 min- 1) 和垂体 (0.009 min- 1) 中最低，而在肾脏 (0.587 min- 1) 和肝脏 (0.800 min- 1) 中最高。 Ki 在心肌中最大（0.601±0.259 mL/cm3/min），而在骨髓中最小（0.028±0.022 mL/cm3/min）。揭示了三组具有相似动力学特征的器官：（1）甲状腺、肺、脾、胰腺和肾； (2)肝脏和肌肉； (3)皮质、白质、小脑、垂体、腮腺、颌下腺、心肌、骨、骨髓。多个器官中存在明显的k3，2TC和1TCfull之间多个器官中的K1和大多数器官中的k2均发现显着变化，但2TC和1TC4min之间K1和k2具有可比性。[13N]NH3的动力学速率在不同器官之间存在差异。有的器官有明显的13N-氨捕获。器官中 13N-氨动力学指标的正态分布可以作为其在肿瘤成像中潜在用途的参考。© 2024。作者获得 Springer-Verlag GmbH 德国（Springer Nature 旗下公司）的独家许可。

To systematically investigate kinetic metrics and metabolic trapping of [13N]NH3 in organs.Eleven participants performed total-body [13N]NH3 dynamic positron emission tomography (PET). Regions of interest were drawn in organs to obtain time-to-activity curves (TACs), which were fitted with an irreversible two-tissue compartment model (2TC) to investigate constant rates K1, k2 and k3, and to calculate Ki. Additionally, one-tissue compartment model using full data (1TCfull) and the first four minutes of data (1TC4min) were fitted to TAC data. K1 and k2 were compared among different models to assess [13N]NH3 trapping in organs.Kinetic rates of [13N]NH3 varied significantly among organs. The mean K1 ranged from 0.049 mL/cm3/min in the muscle to 2.936 mL/cm3/min in the kidney. The k2 and k3 were lowest in the liver (0.001 min- 1) and in the pituitary (0.009 min- 1), while highest in the kidney (0.587 min- 1) and in the liver (0.800 min- 1), respectively. The Ki was largest in the myocardium (0.601 ± 0.259 mL/cm3/min) while smallest in the bone marrow (0.028 ± 0.022 mL/cm3/min). Three groups of organs with similar kinetic characteristics were revealed: (1) the thyroid, the lung, the spleen, the pancreas, and the kidney; (2) the liver and the muscle; and (3) the cortex, the white matter, the cerebellum, the pituitary, the parotid, the submandibular gland, the myocardium, the bone, and the bone marrow. Obvious k3 was identified in multiple organs, and significant changes of K1 in multiple organs and k2 in most organs were found between 2TC and 1TCfull, but both K1 and k2 were comparable between 2TC and 1TC4min.The kinetic rates of [13N]NH3 differed among organs with some have obvious 13N-anmmonia trapping. The normal distribution of kinetic metrics of 13N-anmmonia in organs can serve as a reference for its potential use in tumor imaging.© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.