Prominent pulmonary artery

This is seen as an enlarged second convex shadow on the left-hand side of the PA chest X-ray (first concave shadow is the aortic knuckle, second is the pulmonary artery, third is the left atrial appendage, and fourth is the left ventricle).

Causes include:

• pulmonary artery hypertension - the various causes are to be found in the section of the system on pulmonary arterial hypertension.
• spurious causes:
  • rotated film
  • pulmonary artery displaced by a large aortic root
  • pulmonary artery displaced by a mediastinal mass
  • a chest X-ray of a corrected transposition

Reference

1. Kelly B. The chest radiograph. Ulster Med J. 2012 Sep;81(3):143–148.