Schroeder Tobias, Vidal Melo Marcos F, Musch Guido, Harris R Scott, Venegas Jose G, Winkler Tilo
Department of Anesthesia and Critical Care, Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA.
Acad Radiol. 2008 Jun;15(6):763-75. doi: 10.1016/j.acra.2007.12.016.
Dynamic positron emission tomographic imaging of the radiotracer 2-deoxy-2-[(18)F]fluoro-D-glucose ((18)F-FDG) is increasingly used to assess metabolic activity of lung inflammatory cells. To analyze the kinetics of (18)F-FDG in brain and tumor tissues, the Sokoloff model has been typically used. In the lungs, however, a high blood-to-parenchymal volume ratio and (18)F-FDG distribution in edematous injured tissue could require a modified model to properly describe (18)F-FDG kinetics.
We developed and validated a new model of lung (18)F-FDG kinetics that includes an extravascular/noncellular compartment in addition to blood and (18)F-FDG precursor pools for phosphorylation. Parameters obtained from this model were compared with those obtained using the Sokoloff model. We analyzed dynamic PET data from 15 sheep with smoke or ventilator-induced lung injury.
In the majority of injured lungs, the new model provided better fit to the data than the Sokoloff model. Rate of pulmonary (18)F-FDG net uptake and distribution volume in the precursor pool for phosphorylation correlated between the two models (R(2)=0.98, 0.78), but were overestimated with the Sokoloff model by 17% (P< .05) and 16% (P< .0005) compared to the new one. The range of the extravascular/noncellular (18)F-FDG distribution volumes was up to 13% and 49% of lung tissue volume in smoke- and ventilator-induced lung injury, respectively.
The lung-specific model predicted (18)F-FDG kinetics during acute lung injury more accurately than the Sokoloff model and may provide new insights in the pathophysiology of lung injury.
放射性示踪剂2-脱氧-2-[(18)F]氟-D-葡萄糖（(18)F-FDG）的动态正电子发射断层显像越来越多地用于评估肺炎症细胞的代谢活性。为分析(18)F-FDG在脑和肿瘤组织中的动力学，通常使用索科洛夫模型。然而，在肺中，高血实质体积比以及水肿损伤组织中的(18)F-FDG分布可能需要一个修正模型来恰当地描述(18)F-FDG动力学。
我们开发并验证了一种新的肺(18)F-FDG动力学模型，该模型除血液和用于磷酸化的(18)F-FDG前体池外，还包括一个血管外/非细胞区室。将该模型获得的参数与使用索科洛夫模型获得的参数进行比较。我们分析了15只因烟雾或呼吸机诱导肺损伤的绵羊的动态PET数据。
在大多数受损肺中，新模型比索科洛夫模型更能拟合数据。两种模型之间，肺(18)F-FDG净摄取率和磷酸化前体池中的分布容积具有相关性（R(2)=0.98，0.78），但与新模型相比，索科洛夫模型分别高估了17%（P<0.05）和16%（P<0.0005）。在烟雾诱导和呼吸机诱导的肺损伤中，血管外/非细胞(18)F-FDG分布容积范围分别高达肺组织体积的13%和49%。
肺特异性模型比索科洛夫模型更准确地预测了急性肺损伤期间的(18)F-FDG动力学，可能为肺损伤的病理生理学提供新的见解。
