The fetal lung-to-liver signal intensity ratio on magnetic resonance imaging as a predictor of outcomes from isolated congenital diaphragmatic hernia.

Purpose: We investigated the developmental changes in the unaffected contralateral lungs of patients with isolated left-sided congenital diaphragmatic hernia (CDH) using signal intensity ratios on prenatal magnetic resonance imaging (MRI) and determined whether these changes correlated with clinical outcomes.

Methods: We performed 47 fetal MRI screens on 30 patients with isolated left-sided CDH. A cohort of 88 fetuses was selected as the control. We calculated the lung-to-liver signal intensity ratio (LLSIR) using region of interest analysis and compared LLSIR between the groups and between those in the CDH group with good and poor prognoses.

Results: In the control group, LLSIR increased as pregnancy progressed [regression line = 2.232 + 0.135 × (GW-23), r = 0.669]. In the CDH group, especially in the poor prognosis group, LLSIR did not significantly increase as pregnancy progressed [regression line for good prognosis = 1.827 + 0.092 × (gestational week-23), r = 0.733; regression line for poor prognosis = 1.731 + 0.025 × (gestational week-23), r = 0.634].

Conclusion: Fetal LLSIR on T2-weighted MRI is an accurate marker of fetal lung maturity that correlates with postnatal survival and can potentially be used as a prognostic parameter in CDH management.