Q. Can you explain Pneumothorax?

Air in the pleural cavity manifests in a number of ways on the CXR, depending on the volume of air and position of the patient. The typical findings of a pneumothorax are an area of marked radiolucency, with absent vascular markings, and visibility of the adjacent lung margin. On an erect film, a small pneumothorax would be identified at the lung apex. Larger pneumothoraces are easily identified by their radiolucency and the adjacent collapsed lung. A tension pneumothorax would increase the volume of the ipsilateral thoracic cavity by flattening the diaphragm, widening the rib interspaces, displacing the mediastinum to the opposite side and causing complete collapse of the lung.