Magnetic resonance imaging of the fetus in congenital intrathoracic disorders: preliminary observations.

Advances in magnetic resonance imaging (MRI) provide high-quality images of the intrathoracic organs. We studied the ability of MRI to define spatial relationships of the fetal lungs and measured lung volume in two cases of congenital diaphragmatic hernia (CDH), one of severe oligohydramnios secondary to bilateral cystic renal dysplasia and one case of prenatal chylothorax. We performed pelvic MRI using single-shot fast spin echo (SSFSE) pulse sequence in four pregnant women referred because of abnormal prenatal ultrasound (US) findings associated with pulmonary hypoplasia. The exact anatomic position of the contents of the hernia in CDH, including the position of the liver, was better defined with MRI. Pleural effusions were identified as well as the renal abnormality in the case of oligohydramnios. Lung volume was measured and the degree of pulmonary hypoplasia was quantified in every case. Lung-to-thorax ratio was calculated in the case of fetal chylothorax. Ongoing work suggests that MRI can provide additional detailed quantitative information in prenatal disorders associated with fetal lung compression and resulting hypoplasia. Correlation of fetal lung volume with postnatal management and outcome may affect prognosis in these cases.