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

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. 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. In the control group, LLSIR increased as pregnancy progressed [regression line = 2.232 + 0.135 x (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 x (gestational week-23), r = 0.733; regression line for poor prognosis = 1.731 + 0.025 x (gestational week-23), r = 0.634]. 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.