Pulmonary, Lung and Respiratory Imaging Sheffield (POLARIS), Imaging Sciences, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom.
Department of Child Health, School of Medicine, Cardiff University, Cardiff, United Kingdom.
Am J Respir Crit Care Med. 2023 Jan 1;207(1):89-100. doi: 10.1164/rccm.202203-0606OC.
Preterm birth is associated with low lung function in childhood, but little is known about the lung microstructure in childhood. We assessed the differential associations between the historical diagnosis of bronchopulmonary dysplasia (BPD) and current lung function phenotypes on lung ventilation and microstructure in preterm-born children using hyperpolarized Xe ventilation and diffusion-weighted magnetic resonance imaging (MRI) and multiple-breath washout (MBW). Data were available from 63 children (aged 9-13 yr), including 44 born preterm (⩽34 weeks' gestation) and 19 term-born control subjects (⩾37 weeks' gestation). Preterm-born children were classified, using spirometry, as prematurity-associated obstructive lung disease (POLD; FEV < lower limit of normal [LLN] and FEV/FVC < LLN), prematurity-associated preserved ratio of impaired spirometry (FEV < LLN and FEV/FVC ⩾ LLN), preterm-(FEV ⩾ LLN) and term-born control subjects, and those with and without BPD. Ventilation heterogeneity metrics were derived from Xe ventilation MRI and SF MBW. Alveolar microstructural dimensions were derived from Xe diffusion-weighted MRI. Xe ventilation defect percentage and ventilation heterogeneity index were significantly increased in preterm-born children with POLD. In contrast, mean Xe apparent diffusion coefficient, Xe apparent diffusion coefficient interquartile range, and Xe mean alveolar dimension interquartile range were significantly increased in preterm-born children with BPD, suggesting changes of alveolar dimensions. MBW metrics were all significantly increased in the POLD group compared with preterm- and term-born control subjects. Linear regression confirmed the differential effects of obstructive disease on ventilation defects and BPD on lung microstructure. We show that ventilation abnormalities are associated with POLD, and BPD in infancy is associated with abnormal lung microstructure.
早产与儿童期肺功能降低有关，但对于儿童期肺部微观结构知之甚少。我们使用超极化氙气通气和弥散加权磁共振成像（MRI）及多次呼吸冲洗法（MBW）评估了支气管肺发育不良（BPD）的历史诊断与早产儿童肺通气和微观结构的当前肺功能表型之间的差异关联。研究数据来自 63 名儿童（9-13 岁），其中 44 名出生于早产（≤34 周），19 名足月出生（≥37 周）。使用肺活量计，根据肺功能检查结果将早产出生的儿童分为与早产相关的阻塞性肺疾病（POLD；FEV<正常下限[LLN]和 FEV/FVC<LLN）、与早产相关的肺功能检查结果正常但比值受损（FEV<LLN 和 FEV/FVC≥LLN）、早产（FEV≥LLN）和足月出生的对照组，以及有无 BPD 的儿童。从氙气通气 MRI 和 SF MBW 中得出通气异质性指标。从氙气弥散加权 MRI 中得出肺泡微观结构尺寸。POLD 早产儿的氙气通气缺陷百分比和通气异质性指数显著增加。相比之下，BPD 早产儿的平均氙气表观扩散系数、氙气表观扩散系数四分位距和氙气平均肺泡尺寸四分位距显著增加，表明肺泡尺寸发生了变化。与早产和足月对照组相比，POLD 组的 MBW 指标均显著增加。线性回归证实了阻塞性疾病对通气缺陷和 BPD 对肺部微观结构的差异影响。我们表明，通气异常与 POLD 相关，而婴儿期的 BPD 与肺部微观结构异常相关。
