CXR AP and lateral (above) shows complete opacification of the left hemithorax and tracheal and mediastinal shift to the left and hyperexpansion of the right lung. CXR AP taken during a bronchogram (below left) shows absence of the left mainstem bronchus. AP image from a pulmonary angiogram (below right) shows a normal appearing right main pulmonary artery and absence of the left pulmonary artery.