Congenital overinflation: prenatal MRI and US findings and outcomes

The purpose is to describe fetal MR and US findings of congenital overinflation (CO) and to correlate with postnatal outcome.

Two radiologists reviewed fetal MR and US images in 25 fetuses diagnosed with CO. Lesion size, appearance, location, and presence of hydrops were documented. Chart review was performed for pregnancy outcome, postnatal imaging, interventions, histopathology, and clinical outcome.

All lesions demonstrated primarily homogeneous increased echogenicity and MR signal with absent pulmonary vascular distortion. A tubular cystic hilar structure was consistent with a dilated bronchus (68% MR, 25% US). The right lower (32%) and left lower (23%) lobes were most commonly involved. Two cases with central bronchial obstruction resulted in perinatal demise. Of 23 live births, 17 were asymptomatic, 1 symptomatic, and 5 lost to follow-up. Postnatal CT was performed in 17 of 18 patients confirming CO. Histopathology in nine patients revealed bronchial anomalies with hyperinflated (n = 7) or polyalveolar lung (n = 2). Nine patients were observed and remained asymptomatic.

Fetal MR and US demonstrate a consistent pattern of imaging findings in fetuses with CO. Many cases are asymptomatic and can be managed with nonsurgical conservative therapy. CO because of central bronchial obstruction is associated with a guarded prognosis. © 2016 John Wiley & Sons, Ltd.