Service Siamu, VetAgro Sup, Campus Vétérinaire de Lyon, Marcy l'Etoile, France.
J Nucl Med. 2013 Sep;54(9):1653-60. doi: 10.2967/jnumed.112.116699. Epub 2013 Aug 1.
Pulmonary blood flow (PBF) is a critical determinant of oxygenation during acute lung injury (ALI). PET/CT with (18)F-FDG allows the assessment of both lung aeration and neutrophil inflammation as well as an estimation of the regional fraction of blood (FB) if compartmental modeling is used to quantify (18)F-FDG pulmonary uptake. The aim of this study was to validate the use of FB to assess PBF, with PET and compartmental modeling of (15)O-H2O kinetics as a reference method, in both control animals and animals with ALI. For the purpose of studying a wide range of PBF values, supine and prone positions and various positive end-expiratory pressures (PEEPs) and tidal volumes (V(T)s) were selected.
Pigs were randomized into 3 groups in which ALI was induced by HCl inhalation: pigs studied in the supine position with a low PEEP (5 ± 3 [mean ± SD] cm of H2O; n = 9) or a high PEEP (12 ± 1 cm of H2O; n = 8) and pigs studied in the prone position with a low PEEP (6 ± 3 cm of H2O; n = 9). Also included were a control group that did not have ALI (n = 6) and 2 additional groups (n = 6 each) that had a high V(T) to maintain a transpulmonary pressure of greater than or equal to 35 cm of H2O and that either received HCl inhalation or did not receive HCl inhalation. PBF and FB were measured with PET and compartmental modeling of (15)O-H2O and (18)F-FDG kinetics in 10 lung regions along the anterior-to-posterior lung dimension, and both were expressed in each region as a fraction of their values in the whole lung.
PBF and FB were strongly correlated (R(2) = 0.9), with a slope of the regression line close to unity and a negligible intercept. The mean difference between PBF and FB was 0, and the 95% limits of agreement were -0.035 to 0.035. This good agreement between methods was obtained in both normal and injured lungs and under a wide range of V(T), PEEP, and regional PBF values (7-71 mL/kg, 0-15 cm of H2O, and 24-603 mL·min(-1)·100 mL of lung(-1), respectively).
FB assessed with (18)F-FDG is a good surrogate for PBF in both normal animals and animals with ALI. PET/CT has the potential to be used to study ventilation, perfusion, and lung inflammation with a single tracer.
使用（15）O-H2O 动力学的 PET 和房室模型来评估（18）F-FDG 肺摄取，评估（18）F-FDG 动力学中的局部 FB 以评估肺血流（PBF），以此作为参考方法，在对照动物和急性肺损伤（ALI）动物中验证 FB 的使用。为了研究广泛的 PBF 值，选择了仰卧位和俯卧位以及不同的呼气末正压（PEEP）和潮气量（VT）。
将猪随机分为 3 组，通过吸入 HCl 诱导 ALI：仰卧位低 PEEP（5 ± 3 [均值 ± SD] cm H2O；n = 9）或高 PEEP（12 ± 1 cm H2O；n = 8），以及俯卧位低 PEEP（6 ± 3 cm H2O；n = 9）。还包括一个没有 ALI 的对照组（n = 6）和另外两个组（每组 n = 6），它们接受高 VT 以维持大于或等于 35 cm H2O 的跨肺压，并且要么接受 HCl 吸入，要么不接受 HCl 吸入。使用（15）O-H2O 和（18）F-FDG 动力学的 PET 和房室模型在整个肺前-后肺尺寸上的 10 个肺区测量 PBF 和 FB，并将它们在每个区域的值表示为整个肺的分数。
PBF 和 FB 呈强相关性（R2 = 0.9），回归线斜率接近 1，截距可忽略不计。PBF 和 FB 的平均差异为 0，95%的一致性区间为 -0.035 至 0.035。在正常和受损的肺中以及在广泛的 VT、PEEP 和区域 PBF 值（分别为 7-71 mL/kg、0-15 cm H2O 和 24-603 mL·min-1·100 mL 肺-1）下，都获得了这种方法之间的良好一致性。
使用（18）F-FDG 评估的 FB 是正常动物和 ALI 动物中 PBF 的良好替代物。PET/CT 具有使用单个示踪剂研究通气、灌注和肺炎症的潜力。
