Atelectasis (summary)

Dr Derek Smith and Dr Jeremy Jones et al.

Atelectasis describes loss of lung volume secondary to collapse. It has many causes, the root of which is bronchial obstruction with absorption of distal gas. Atelectasis may be subsegmental, segmental, lobar, or involve the entire lung. 

Reference article

This is a summary article; read more in our article on lobar collapse.

  • pathophysiology
    • caused by bronchial obstruction
      • e.g. inflammation, infection, cancer, foreign body
    • results in distal gaseous absorption
      • partial or complete loss of volume distal to the obstruction
      • lung parenchyma collapses down
        • associated volume loss
  • role of imaging
    • confirm lung collapse
      • differentiate from air-space opacification
    • help to determine the cause (may need CT)
    • assess for complications, e.g. pleural effusion
  • radiographic features
    • chest x-ray
      • increased density and reduced volume
    • ​​CT chest
      • more accurately depicts the involved segment
      • helpful in determining the cause, e.g. cancer
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Article information

rID: 51373
System: Chest
Synonyms or Alternate Spellings:

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Cases and figures

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    Case 1: right upper lobe collapse in cancer
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    Case 2: left lower lobe collapse
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    Case 3: right middle lobe collapse on CT
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