Evaluation of regional lung mass and growth in neonates with bronchopulmonary dysplasia using ultrashort echo time magnetic resonance imaging

Rationale: Bronchopulmonary dysplasia (BPD) is the most common long term pulmonary morbidity in premature infants and is characterized by impaired lung growth and development. We hypothesized that lung mass growth is a critical factor in determining outcomes in infants with BPD.Objectives: To measure regional lung density and mass in infants with BPD and compare to clinical variables.Methods: We conducted a retrospective cohort study of neonates (n = 5 controls, n = 46 with BPD). Lung mass and lung density were calculated using ultrashort echo time (UTE) magnetic resonance imaging (MRI).Measurements and Main Results: Lung mass increased with increasing corrected gestational age at the time of MRI in all patients. Total, right, and left lung mass in infants with BPD trended higher than control infants (65.7 vs. 49.9 g, 36.2 vs. 26.8 g, 29.5 vs. 23.1 g, respectively). Babies with BPD who survived to discharge had higher relative lung mass than control infants and infants with BPD that did not survive to discharge (21.6 vs. 15.7 g/kg, p = .01). There was a significant association between the rate of lung mass growth and linear growth at the time of MRI (p = .034).Conclusions: Infants with BPD are capable of building lung mass over time. While this lung mass growth in infants with BPD may not represent fully functional lung tissue, higher lung mass growth is associated with increased linear growth.