Fetal lung growth represented by longitudinal changes in MRI-derived fetal lung volume parameters predicts survival in isolated left-sided congenital diaphragmatic hernia

Objective: The aim of this study was to evaluate fetal lung growth rate for isolated left-sided congenital diaphragmatic hernia (CDH) using serial magnetic resonance imaging (MRI)-based volumetric measures. Methods: Early and late gestational (22-30 and >30weeks' gestation) lung volumetry was obtained by fetal MRI in 47 cases of isolated left-sided CDH. At both of these time points, lung volume indices, including total lung volume (TLV), observed to expected TLV (o/e TLV), and percentage of predicted lung volume (PPLV) as well as their change rates (Δ) and relative Δ during gestation were calculated and analyzed in regard to their capacity to predict neonatal survival. Results: TLV, o/e TLV, and PPLV had various changes during gestation. Late TLV, early and late o/e TLV, and late PPLV were predictive of neonatal survival. Non-survivors had lower ΔTLV and more negative relative ΔPPLV than survivors (1.18 vs 1.85mL/week, P=0.004 and -4.15%/week vs -1.95%/week, P=0.002, respectively). Conclusions: The severity of pulmonary hypoplasia is dynamic and can worsen in the third trimester. MRI lung volumetry repeated in late gestation can provide additional information on individual lung growth that may facilitate prenatal counseling and focus perinatal management.