Structural and Functional Lung Assessment in Neonates With Moderate to Severe Bronchopulmonary Dysplasia Using 3D Ultra‐Short Echo Time MRI

ABSTRACT Background 2D multi‐slice MRI techniques for evaluating regional ventilation in neonatal lung diseases, including bronchopulmonary dysplasia (BPD), have limited through‐plane resolution, potentially missing heterogeneous lung abnormalities. 3D ultra‐short echo time (UTE) MRI phase‐resolved functional lung (PREFUL) improves spatial resolution but has not been used to evaluate infants with BPD. Purpose To demonstrate the feasibility of 3D UTE MRI for structural and functional assessment in infants with BPD. Study Type Retrospective. Population A total of 28 infants with BPD (female: male = 8:20; 14 required invasive ventilation at MRI, 14 required non‐invasive ventilation). Field Strength/Sequence Free‐breathing, respiratory bellows‐gated (acquired 1.19–1.25 mm 3 isotropic) 3D gradient echo UTE MRI on a 1.5 T scanner. Assessment Images were retrospectively reconstructed into 24 respiratory phases with motion‐resolved reconstruction using compressed sensing. Regional ventilation (RVent), flow‐volume loop cross correlation metric (FVL‐CM), and corresponding ventilation defect maps (VDP RVent , VDP FVL‐CM , and the combination, VDP combined ) were derived using the 3D PREFUL method. Structural lung abnormalities were assessed by two readers using a modified Ochiai scoring system, and parenchyma was defined as normal intensity, hypointense, or hyperintense. Statistical Tests The Mann–Whitney U Test, Spearman's correlation, and the Kruskal–Wallis test with Dunn's multiple‐comparisons tests were used. Statistical significance was defined as p < 0.05. Results In the mechanically ventilated infants VDP FVL‐CM (median IQR = 45.8 28.5–55.9%) and VDP combined (57.2% 35.2–69.3%) were significantly higher as compared to non‐ventilated patients (VDP FVL‐CM = 22.8% 17.2–34.7% and VDP combined = 30.7 25.1–43.9%). All PREFUL MRI VDP measures significantly correlated with total lung score (all ρ ≥ 0.45). RVent was significantly lower in hyperintense regions (0.06 0.04–0.08 mL/mL) compared to normal intensity regions (0.09 0.07–0.13 mL/mL), whereas FVL‐CM was significantly decreased in hypointense regions (79 66–87%) compared to normal (92 90–95%) and hyperintense regions (91 81–96%). Data Conclusion UTE MRI is feasible for assessing regional functional lung abnormalities in infants with BPD that directly correlate with reader‐based assessments of parenchymal disease severity. Evidence Level 4. Technical Efficacy Stage 1.