引用

肺通气和应变(变化体积/静息体积)的空间异质性存在于微观水平，并有助于肺损伤。然而，它主要是通过直方图或大的感兴趣区域进行评估。空间异质性也可能影响区域基因表达。我们使用正电子发射断层扫描(PET)/计算机断层扫描(CT)来评估不同长度尺度对机械异质性的贡献，并指导肺损伤生物通路的识别。暴露于轻度(n= 5，仰卧位，n=3，俯卧位)和中度(n=6，仰卧位)全身内毒素血症的绵羊进行保护性通风。在基线时，对CT(轻度组)和PET透射(中度组)扫描的通气情况进行6小时和20小时的长度尺度分析;以及从吸气末和呼气末ct图像配准中获得的体素水平应变(轻微)。腹侧和背侧2-脱氧-2-[(18)F]氟-d-葡萄糖(18F-FDG)- pet动力学参数与组织芯片基因表达相关(中度)。在5 ~ 10 mm长度尺度上曝气和应变非均质性最高，较大的长度尺度包含的应变比例高于曝气非均质性。随着肺损伤的进展，> -10 - mm长度对通气和应变异质性的贡献增加(p < 0.001)，仰卧位比俯卧位动物更高。 Genes expressed with regional correlation to 18F-FDG-PET kinetics (|r|=0.81 [0.78-0.85]) yielded pathways associated with immune system activation and fluid clearance. Normal spatial heterogeneity of aeration and strain suggest larger anatomical and functional determinants of lung strain than aeration heterogeneity. Lung injury and supine position increase the contribution of larger length-scales. 18F-FDG-PET-based categorization of gene expression results in known and novel biological pathways relevant to lung injury. Copyright 2018 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.