Prenatal diagnosis of horseshoe lung: contribution of MRI.

Horseshoe lung is a very rare pulmonary anomaly that is characterized by an isthmus of lung parenchyma bridging the right and left lungs and extending through the mediastinum. We report on the prenatal diagnosis of such a malformation in a 33-week-gestation fetus. The diagnosis was initially suspected on antenatal ultrasonography performed at 33 weeks and confirmed by fetal MRI and subsequent pathological examination after termination of pregnancy. To our knowledge, this is the first reported case of antenatal diagnosis of horseshoe lung.