Aortopulmonary stripe

The aortic-pulmonary stripe is an uncommon feature of frontal chest radiographs and was first described by Keats in 1972 .

It is formed by the interface of the pleural surface of the anterior segment of the left upper lobe contacting the mediastinal fat that is anterolateral to the pulmonary trunk or left pulmonary artery and aortic arch .

Abnormal appearances may reflect different pathologies:

• elevation
  • pneumomediastinum 
• increased lateral convexity
  • anterior mediastinal mass 

Radiological appearance

Plain radiograph

• appears as a triangular opacity or stripe with a lateral edge that extends, from superior to inferior, obliquely across the aortic arch and pulmonary artery
• not commonly seen on frontal chest x-rays