MRI pulmonary artery flow detects lung vascular pathology in preterms with lung disease

Rationale Pulmonary vascular disease (PVD) affects the majority of preterm neonates with bronchopulmonary dysplasia (BPD) and significantly determines long-term mortality through undetected progression into pulmonary hypertension.

Objectives To associate characteristics of pulmonary artery (PA) flow and cardiac function with BPD-associated PVD near term using advanced magnetic resonance imaging (MRI) for improved risk stratification.

Methods Preterms <32 weeks postmenstrual age (PMA) with/without BPD were clinically monitored including standard echocardiography and prospectively enrolled for 3TMRI in spontaneous sleep near term (AIRR study). Semi-manual PA flow quantification (phase-contrast MRI, no BPD n=28, mild n=35, moderate/severe n=25) was complemented by cardiac function assessment (cine MRI).

Measurements and Main Results We identified abnormalities in PA flow and cardiac function, i.e. increased net forward volume (ratio right-over-left), decreased mean relative area change and pathologic right end-diastolic volume to sensitively detect BPD-associated PVD while correcting for PMA (L1OAUC=0.88/sensitivity=0.80/specificity=0.81). We linked these changes to increased right ventricular (RV) afterload (RV-arterial coupling (p=0.02), PA midsystolic notching (p=0.015(t2)), cardiac index (p=1.67×10⁻⁸)) and correlated echocardiographic findings. Identified in moderate/severe BPD, we successfully applied the PA flow model in heterogeneous mild BPD cases, demonstrating strong correlation of PVD probability with indicators of BPD severity, i.e., duration of mechanical ventilation (R=0.62, p=3.7×10⁻⁴) and oxygen supplementation (R=0.58, p=9.2×10⁻⁴).

Conclusions Abnormalities in MRI PA flow and cardiac function exhibit significant, synergistic potential to detect BPD-associated PVD, advancing the possibilities of risk-adapted monitoring.