Pulmonary arterial hypertension

40 year old lady was admitted and found to have severe pulmonary hypertension. A radiograph was taken on admission following which CT was requested to rule out acute or chronic pulmonary thromboembolism. The doppler study of both lower limbs did not reveal any deep venous thrombosis.

Chest radiograph



  • cardiomegaly with elevated cardiac apex
  • enlarged right atrium
  • dense bilateral hilum with positive hilum convergence sign
  • obliteration of left pulmonary bay

CTPA – CT pulmonary angiogram

Axial CTPA
Coronal MIP


  • incidental azygos lobe
  • dilated main pulmonary artery and both right and left pulmonary arteries.
  • pruning of peripheral pulmonary vessels
  • no acute or chronic pulmonary thromboembolism
  • right sided cardiomegaly with RV:LV ratio >1
  • dilated right atrium
  • straightened interventricular septum with mild bowing to left ventricle

azygosmpaRPALPAvent ratio

Key points

It is important to understand the pathophysiology of pulmonary hypertension, possible imaging findings to come to understanding the severity of PAH as well as other mimics.

I am including a presentation I adapted from a radiographics article during my residency for a better understanding.

This will also be a good time to review how to assess cardiomegaly on a frontal radiograph, review hilum overlay and hilum convergence signs.

Read more

  1. Radiopaedia – Pulmonary hypertension
  2. Peña, Elena, et al. “Pulmonary hypertension: how the radiologist can help.” Radiographics 32.1 (2011): 9-32.