D15-05 Non-Contrast Functional Lung MRI Detects Impaired Ventilation and Perfusion in Preterm Children With and Without Bronchopulmonary Dysplasia

Abstract Rationale Children born prematurely are at increased risk for long-term lung impairment, which is more pronounced in those with bronchopulmonary dysplasia (BPD) diagnosed during infancy. The non-contrast, free-breathing MRI technique, phase-resolved functional lung (PREFUL) MRI, has demonstrated sensitivity to regional lung deficits not detected by standard pulmonary function tests in pediatric diseases such as cystic fibrosis, but has not been evaluated in BPD. This study aimed to evaluate and compare regional lung function metrics derived from PREFUL MRI and compare to patient-family reported symptoms and quality of life. Methods School age (all 6 years old) preterm-children with BPD (n = 28) and without BPD (n = 24), and term age-matched controls (n = 16), performed MRI on a 3T scanner (Philips Ingenia) and completed the St. George’s Respiratory Questionnaire (SGRQ). Regional ventilation and perfusion maps (4-5 coronal slices, resolution per slice=4x4x15 mm3) were generated using the PREFUL method; low ventilation and blood signal were quantified relative to the whole-lung volume as ventilation and perfusion defect percentages (VDP and QDP, respectively). The upper limit of normal for VDP and QDP was determined from the term controls. Kruskal Wallis tests with post-hoc Dunn’s tests were used for inter-group comparisons and metrics were correlated using Spearman’s rank coefficient. Results QDP was significantly elevated in preterm BPD children as compared to healthy term controls (p = 0.002), and non-BPD preterm children (p = 0.043) (Figure 1a). VDP showed no significant group differences (Figure 1b, all p 0.132), though there were a greater proportion of non-BPD preterm (17%) and BPD (25%) children above the ULN than term controls (6%). VDP correlated with SGRQ symptom (r = 0.37, p = 0.002), activity (r = 0.26, p = 0.031), impact (r = 0.31, p = 0.011), and total score (r = 0.37, p = 0.002). QDP did not correlate with any SGQR score (all p 0.133). Representative ventilation and perfusion maps (Figure 1c) show elevated VDP in a preterm child without BPD, and a child with BPD with elevated VDP, QDP, and SGRQ score. Duration in the neonatal intensive care unit was associated with VDP (r = 0.31, p = 0.011) and QDP (r = 0.42, p = 0.0003). Conclusion Lung function abnormalities were observed in preterm children both with and without BPD. Half of those with BPD demonstrated elevated QDP, reflecting potential hypoxic vasoconstriction and subclinical pulmonary vascular disease. Increased VDP, indicative of airway obstruction, was associated with SGRQ scores capturing symptom burden, activity limitation, and psychosocial impact. Thus, PREFUL MRI may be useful for detecting and measuring lung disease in preterm children, with relevance to clinical outcomes. This abstract is funded by: NHLBI R01 HL 164420