Image Phenotyping of Preterm-Born Children Using Hyperpolarized 129Xe Lung Magnetic Resonance Imaging and Multiple-Breath Washout

Rationale: Preterm birth is associated with low lung function in childhood, but little is known about the lung microstructure in childhood. Objectives: 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 129Xe ventilation and diffusion-weighted magnetic resonance imaging (MRI) and multiple-breath washout (MBW). Methods: 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; FEV1, lower limit of normal [LLN] and FEV1/FVC, LLN), prematurity-associated preserved ratio of impaired spirometry (FEV1, LLN and FEV1/FVC >= LLN), preterm-(FEV1 >= LLN) and term-born control subjects, and those with and without BPD. Ventilation heterogeneity metrics were derived from 129Xe ventilation MRI and SF6 MBW. Alveolar microstructural dimensions were derived from Xe-129 diffusion-weighted MRI. Measurements and Main Results: Xe-129 ventilation defect percentage and ventilation heterogeneity index were significantly increased in preterm-born children with POLD. In contrast, mean Xe-129 apparent diffusion coefficient, Xe-129 apparent diffusion coefficient interquartile range, and Xe-129 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. Conclusion: We show that ventilation abnormalities are associated with POLD, and BPD in infancy is associated with abnormal lung microstructure.

Automated summary

This study aimed to investigate the associations between bronchopulmonary dysplasia (BPD) and lung function phenotypes on lung ventilation and microstructure in preterm-born children. The results showed that preterm-born children with POLD had increased ventilation abnormalities, while those with BPD had abnormal lung microstructure.