Chest Imaging

Horseshoe lung

partial fusion of right and left lungs posterior to the heart and anterior to the oesophagus. It is usually associated with cardiovascular and bronchopulmonary anomalies. Although highly improbable from an embryological viewpoint, this entity can be seen in both the scimitar syndrome and the congenital pulmonary venolobar syndrome. The condition is characterized by the herniation of a segment of the right lung to the base of the left lung where it remains supplied by the right bronchial tree and the right pulmonary artery. In the absence of symphysis unifying both lungs behind the heart, there may be a close contact between the two individual pleural cavities. In that particular case the retrocardiac hernia of the right lung can be called "crossover lung segment". Although very rare, horseshoe lung must be systematically looked for in the preoperative management of patients with scimitar syndrome in order to avoid the risk of a postoperative bilateral pneumothorax.

JR - MRJ