Left paratracheal stripe

The left paratracheal stripe is formed by the interface of the medial pleural surface of the left upper lobe and left lateral border of the trachea and/or the fat adjacent  with air within each structure forming the outline. It may not be visible if the left upper lobe contacts the left subclavian artery or left common carotid artery .

Abnormal widening or contour may be due to :

Recognition of any abnormality in the left paratracheal stripe is invaluable in ensuring the appropriateness in further investigation with CT.

Radiological appearance

Plain radiograph
  • seen on ~25% (range 21-31%) of PA chest x-rays 
  • appears as a vertical stripe of variable thickness, that extends from the aortic arch to the left subclavian artery