Learning Radiology xray montage
 
 
 
 
 
 

Total Atelectasis of an Entire Lung


General Considerations

  • All types of atelectasis involve loss of volume in some or all of a lung with resultant increased density of the involved lung
  • The atelectasis referred to here is that caused by bronchial obstruction, usually a tumor (i.e. a bronchogenic carcinoma), a foreign body or a mucus plug
  • In asthmatics, chronic inflammation along with thicker and more viscous mucous leads to plugging and impaction of the bronchi 

Signs of atelectasis -- general 

  • Increase in density of the affected lung
  • Displacement of the fissures or the mediastinum (heart or trachea) towards the side of the atelectasis
  • Crowding of the vessels and bronchial tree in the area of volume loss
  • Elevation of the hemidiaphragm
  • Overaeration of the opposite lung 

Total Atelectasis of an Entire Lung

 

  • Complete atelectasis is almost always due to obstruction of the main bronchus either by tumor (intrinsic, i.e., bronchogenic carcinoma or extrinsic, i.e., enlarged nodes), mucus plugging in post-operative patients or asthmatics, or malposition of an endotracheal tube

  • Imaging findings
    • Complete opacification of the hemithorax
    • Silhouetting of the heart border on the frontal view on the side of the atelectasis
    • Shift of the heart towards the side of atelectasis
    • Shift of the trachea towards the side of the atelectasis
    • Elevation of the hemidiaphragm will occur, but the hemidiaphragm may not be visible on conventional radiographs

  • Differential Diagnosis
    • Large pleural effusion - shift AWAY from the side of opacification
    • Pneumonia of the entire lung - air bronchograms may be present
    • Prior pneumonectomy - missing 4th or 5th ribs; metallic sutures from surgery

  • Treatment
    • Bronchoscopy 
    • Surgery, if necessary

 

atelectasis whole lung, left

Atelectasis, Left Lung. Frontal radiograph of the chest demonstrates complete opacification of the left hemithorax (red arrow) There is a shift of the mobile mediastinal structures towards the side of the atelectasis (white arrows) and the trachea is also shifted towards the side of opacification (black arrow).


Fraser and Pare