The chest x-ray shows triangular peripheral based pleural opacity with apex towards the hilum. This is Hampton’s hump.

There are linear bands of atelectasis in the right mid zone. The patient was diagnosed with proximal PE on CTPA with the pleural opacity corresponding to area of pulmonary infarction.

Hampton’s hump is a rare but useful chest x-ray sign of pulmonary embolism. Rare because of the rich collateral blood supply from the bronchial arteries.

Reference: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3830415/