Wellman Tyler J, Winkler Tilo, Vidal Melo Marcos F
Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St, Boston, MA, 02114, USA.
Ann Biomed Eng. 2015 Nov;43(11):2722-34. doi: 10.1007/s10439-015-1327-2. Epub 2015 May 5.
¹⁸F-FDG-PET is increasingly used to assess pulmonary inflammatory cell activity. However, current models of pulmonary ¹⁸F-FDG kinetics do not account for delays in ¹⁸F-FDG transport between the plasma sampling site and the lungs. We developed a three-compartment model of ¹⁸F-FDG kinetics that includes a delay between the right heart and the local capillary blood pool, and used this model to estimate regional pulmonary perfusion. We acquired dynamic ¹⁸F-FDG scans in 12 mechanically ventilated sheep divided into control and lung injury groups (n = 6 each). The model was fit to tracer kinetics in three isogravitational regions-of-interest to estimate regional lung transport delays and regional perfusion. ¹³NN bolus infusion scans were acquired during a period of apnea to measure regional perfusion using an established reference method. The delayed input function model improved description of ¹⁸F-FDG kinetics (lower Akaike Information Criterion) in 98% of studied regions. Local transport delays ranged from 2.0 to 13.6 s, averaging 6.4 ± 2.9 s, and were highest in non-dependent regions. Estimates of regional perfusion derived from model parameters were highly correlated with perfusion measurements based on ¹³NN-PET (R² = 0.92, p < 0.001). By incorporating local vascular transports delays, this model of pulmonary ¹⁸F-FDG kinetics allows for simultaneous assessment of regional lung perfusion, transit times, and inflammation.
¹⁸F - FDG - PET越来越多地用于评估肺部炎症细胞活性。然而，目前的肺部¹⁸F - FDG动力学模型未考虑¹⁸F - FDG在血浆采样部位与肺部之间转运的延迟。我们开发了一种¹⁸F - FDG动力学三室模型，该模型包括右心与局部毛细血管血池之间的延迟，并使用此模型估计区域肺灌注。我们对12只机械通气绵羊进行了动态¹⁸F - FDG扫描，将其分为对照组和肺损伤组（每组n = 6）。该模型与三个等重力感兴趣区域的示踪剂动力学相拟合，以估计区域肺转运延迟和区域灌注。在呼吸暂停期间进行¹³NN团注扫描，使用既定的参考方法测量区域灌注。在98%的研究区域中，延迟输入函数模型改善了¹⁸F - FDG动力学的描述（较低的赤池信息准则）。局部转运延迟范围为2.0至13.6秒，平均为6.4±2.9秒，在非下垂区域最高。从模型参数得出的区域灌注估计值与基于¹³NN - PET的灌注测量高度相关（R² = 0.92，p < 0.001）。通过纳入局部血管转运延迟，这种肺部¹⁸F - FDG动力学模型允许同时评估区域肺灌注、通过时间和炎症。
