Pneumothorax

  • Etiology: barotrauma, blunt thoracic trauma
  • CXR upright: gravity drops lung inferiorly and medially and shows distinct pleural edge with no lung markings lateral to it
  • CXR decubitus: gravity drops lung inferiorly and shows distinct pleural edge with no lung markings superior to it
  • CXR cross-table lateral: gravity drops lung inferiorly and may show pleural edge with no lung markings anterior to it – but does not tell you which side the pneumothorax is on
  • CXR supine: gravity drops lung posteriorly and usually fails to reveal pleural edge, air accumulates anteromedially so pneumothorax can manifest itself as increased lucency throughout hemithorax / sharp heart border / deep sulcus sign = increased lucency in costophrenic angle
  • Note: if you suspect small pneumothorax on CXR supine get decubitus image with suspected side up to confirm
  • Note: tension pneumothorax is diagnosed when there is mediastinal shift which implies underlying tension
  • Complications: tension pneumothorax causes torquing of great vessels, vascular compromise, requires immediate treatment
  • Clinical: in premature infant lungs are stiff (noncompliant) so don’t collapse like adult lung

Cases of Pneumothorax

CXR of tension pneumothorax
AP CXR (above) shows increased lucency in the left hemithorax when compared to the right and a deep sulcus sign is seen. There is mediastinal shift to the right implying underlying tension. Right lateral decubitus CXR (below) shows a clear pleural edge.
CXR of pneumothorax
Upright CXR shows a distinct right pleural edge with no lung markings lateral to it and the right lung collapsing inferiorly and medially.
CXR of pneumothorax
Left lateral decubitus CXR shows a distinct left pleural edge with no lung markings superior to it and the left lung collapsing inferiorly.
CXR of pneumothorax
Cross-table lateral CXR shows air collecting anteriorly in the thorax without a clear pleural edge. The thymus is also outlined by air.
CXR of pneumothorax
Supine CXR shows multiple left-sided rib fractures and the deep sulcus sign which is increased lucency in the left costophrenic angle. No definite pleural edge is seen.
CXR of pneumothorax
Supine CXR shows the left mediastinal and cardiac border is much more sharp in appearance than the right mediastinal and cardiac border.
CXR of pneumothorax
Supine CXR shows a large amount of air in the right pleural space with inversion of the right hemidiaphragm and mediastinal shift to the left. There is also evidence of pulmonary interstitial emphysema in the right lung.