Discordant prenatal ultrasound and fetal MRI in CDH: wherein lies the truth?

Purpose Prenatal risk assessment of congenital diaphragmatic hernia (CDH) relies on prenatal ultrasound (U/S) and fetal magnetic resonance imaging (MRI). When the modalities differ in prognosis, it is unclear which is more reliable. Methods Retrospective chart review identified cases of prenatally diagnosed CDH from 4/2010–6/2018 meeting inclusion criteria. Demographic, radiologic, and postnatal outcomes data were collected.Ultrasound- versus MRI-based prognosis (mild, moderate, and severe) was compared with clinical outcomes. Kappa measures compared congruency in disease severity scaling between imaging modalities, while logistic regression and receiver operating characteristics curves compared the ability of each modality to predict outcomes. Results Forty-two patients met criteria. Both U/S- and MRI-based prognosis categories differentiated for survival. MRI categories differentiated for ECMO use, surgical repair, and defect type. O/e TFLV better discriminated for survivors and defect type than o/e LHR. Seventeen (40.5%) had discordant prenatal prognostic categories. In 13/17 (76.5%), o/e TFLV predicted higher severity when compared to o/e LHR, but sample size was insufficient to compare accuracy in cases of discordance. Conclusions Clinical outcomes suggest fetal MRI may more accurately predict severe pulmonary hypoplasia compared to prenatal ultrasound. Our analysis suggests fetal MRI is a valuable adjunct in the prenatal evaluation of CDH. Level of Evidence Level III. Type of Study Retrospective Review.