Unilateral hypertranslucent hemithorax

Unilateral hypertranslucent hemithorax has many potential causes. It may be the result of rotation away from an optimal position or because of pathology.


A unilateral hypertranslucent hemithorax may be caused by the positioning of the patient. Rotation away from the radiation beam alters the attenuation of the beam differently on either side of the thorax. When the patient is turned to the right, the right side will be hypertranslucent.  


Where rotation isn't thought to be the cause of the differential transradiancy, it may be useful to consider the potential causes by the structures they involve, in the order in which the radiation beam hit them. The age of the patient is also a factor that should be considered.

A helpful mnemonic is SAFEPOEM.

Chest wall defects - muscle abnormalities
Pleura and pleural space
Pulmonary (ventilation)
Vascular (perfusion)
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Article information

rID: 4996
System: Chest
Section: Approach
Synonyms or Alternate Spellings:
  • Transradiant hemithorax
  • Unilateral hemithorax lucency
  • Unilateral hyperlucent hemithorax

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Cases and figures

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    Left Mastectomy
    Case 1: mastectomy
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    Case 2: compensatory hyperinflation
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    Case 3: pneumothorax
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    Poland syndrome
    Case 4: Poland syndrome
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    Study obtained wi...
    Case 5 : right haemothorax
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    Case 6: Heimlich valve and haemopneumothorax
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    Case 7: re-expansion pulmonary oedema
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    Case 8: Swyer-James syndrome
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