Congenital diaphragmatic hernia: predictive value of MRI relative lung-to-head ratio compared with MRI fetal lung volume and sonographic lung-to-head ratio.

OBJECTIVE

The purpose of this study was to evaluate the prognostic accuracy of a new MRI-based relative lung-to-head ratio in regard to neonatal survival and need for extracorporeal membrane oxygenation (ECMO) in the care of fetuses with congenital diaphragmatic hernia (CDH) and to compare it with the previously described sonographic relative lung-to-head ratio and relative fetal lung volume assessed at antenatal MRI.

MATERIALS AND

METHODS

Sonographic lung-to-head ratio and MRI fetal lung volume were measured in 90 fetuses (mean gestational age, 31.4+/-4.1 weeks) with CDH. Sonographic relative lung-to-head ratio and MRI relative fetal lung volume were assessed by expressing the observed sonographic lung-to-head ratio and MRI fetal lung volume as a percentage of the expected parameter value. The new MRI relative lung-to-head ratio was assessed as a percentage of the expected MRI lung-to-head ratio based on MRI fetal lung volume and MRI head circumference measurements. Measurements for survival and ECMO requirement were determined with the area under the curve (AUC). Data were analyzed for left-sided defects, right-sided defects, and associated liver herniation.

RESULTS

Among fetuses with left-sided CDH, all parameters were excellent in determining neonatal survival and need for ECMO therapy (p <or= 0.0027). Prognostic accuracy was best for the newly devised MRI relative lung-to-head ratio (AUC, 0.816 and 0.807) and lowest for sonographic relative lung-to-head ratio (AUC 0.783 and 0.703). Among fetuses with right-sided defects, the predictive value was lower for all parameters (AUC, 0.788-0.560). All neonates without liver herniation survived.

CONCLUSION

Among fetuses with left-sided CDH, assessment of pulmonary hypoplasia based on MRI relative fetal lung volume and MRI relative lung-to-head ratio is excellent in prediction of neonatal survival and ECMO requirement. The prognostic accuracy is slightly better than that of sonographic relative lung-to-head ratio. Among fetuses with right-sided CDH, the prognostic value of all parameters is lower than those among fetuses with left-sided defects.