Pulmonary Engineering Group, Department of Anesthesiology and Intensive Care Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany
Department of Nuclear Medicine, University Hospital Carl Gustav Carus at the Technische Universität Dresden, Dresden, Germany; and.
J Nucl Med. 2019 Nov;60(11):1629-1634. doi: 10.2967/jnumed.119.226597. Epub 2019 May 3.
PET imaging with F-FDG followed by mathematic modeling of the pulmonary uptake rate (K) is the gold standard for assessment of pulmonary inflammation in experimental studies of acute respiratory distress syndrome (ARDS). However, dynamic PET requires long imaging and allows the assessment of only 1 cranio-caudal field of view (∼15 cm). We investigated whether static F-FDG PET/CT and analysis of SUV or standardized uptake ratios (SUR, uptake time-corrected ratio of F-FDG concentration in lung tissue and blood plasma) might be an alternative to dynamic F-FDG PET/CT and Patlak analysis for quantification of pulmonary inflammation in experimental ARDS. ARDS was induced by saline lung lavage followed by injurious mechanical ventilation in 14 anesthetized pigs (29.5-40.0 kg). PET/CT imaging sequences were acquired before and after 24 h of mechanical ventilation. K and the apparent volume of distribution were calculated from dynamic F-FDG PET/CT scans using the Patlak analysis. Static F-FDG PET/CT scans were obtained immediately after dynamic PET/CT and used for calculations of SUV and SUR Mean K values of the whole imaged field of view and of 5 ventro-dorsal lung regions were compared with corresponding SUV and SUR values, respectively, by means of linear regression and concordance analysis. The variability of the F-FDG concentration in blood plasma (arterial input function) was analyzed. Both for the whole imaged field of view and ventro-dorsal subregions, K was linearly correlated with SUR ( ≥ 0.84), whereas K-SUV correlations were worse ( ≤ 0.75). The arterial input function exhibited an essentially invariant shape across all animals and time points and can be described by an inverse power law. Compared with K, SUR and SUV tracked the same direction of change in regional lung inflammation in 98.6% and 84.3% of measurements, respectively. The K-SUR correlations were considerably stronger than the K-SUV correlations. The good K-SUR correlations suggest that static F-FDG PET/CT and SUR analysis provides an alternative to dynamic F-FDG PET/CT and Patlak analysis, allowing the assessment of inflammation of whole lungs, repeated measurements within the period of F-FDG decay, and faster data acquisition.
正电子发射断层扫描（PET）成像与肺部摄取率（K）的数学模型结合，是评估急性呼吸窘迫综合征（ARDS）实验研究中肺部炎症的金标准。然而，动态 PET 需要长时间的成像，只能评估 1 个颅尾视野（约 15cm）。我们研究了静态 18F-FDG PET/CT 和 SUV 或标准化摄取比值（SUR，肺部组织和血浆中 18F-FDG 浓度的摄取时间校正比值）的分析是否可以替代动态 18F-FDG PET/CT 和 Patlak 分析，用于定量评估实验性 ARDS 中的肺部炎症。通过盐水肺灌洗诱导 ARDS，然后在 14 只麻醉猪（29.5-40.0kg）中进行机械性损伤通气。在机械通气 24 小时前后采集 PET/CT 成像序列。使用 Patlak 分析从动态 18F-FDG PET/CT 扫描中计算 K 和表观分布体积。在动态 PET/CT 后立即获得静态 18F-FDG PET/CT 扫描，并用于计算 SUV 和 SUR 整个成像视野的平均 K 值和 5 个腹背肺区的平均 K 值，分别与相应的 SUV 和 SUR 值进行线性回归和一致性分析。分析血浆中 18F-FDG 浓度（动脉输入函数）的变异性。对于整个成像视野和腹背亚区，K 与 SUR 呈线性相关（≥0.84），而 K-SUV 相关性较差（≤0.75）。在所有动物和时间点，动脉输入函数的形状基本不变，可以用逆幂律来描述。与 K 相比，SUR 和 SUV 在 98.6%和 84.3%的测量中分别跟踪了区域性肺部炎症相同的变化方向。K-SUR 相关性明显强于 K-SUV 相关性。良好的 K-SUR 相关性表明，静态 18F-FDG PET/CT 和 SUR 分析可替代动态 18F-FDG PET/CT 和 Patlak 分析，可用于评估整个肺部炎症、18F-FDG 衰减期间的重复测量以及更快的数据采集。
