(Hyper) Lucent Hemithorax

Causes

• Pneumonectomy
• Initially on the side of the resection; eventually fibrosis can lead to overexpansion of the opposite side
  
  
• Pulmonary embolism
• Usually large pulmonary emboli may lead to oligemia of the affected lung (Westermark sign)
  
  
• Mucous plug
• May result in air-trapping and overaeration
  
  
• Pneumothorax
  
  
• Radical Mastectomy
• Removal of the breast and the underlying pectoralis major and minor muscles along with axillary lymph nodes; in a modified radical, the pectoralis is spared
  
  
• Poland Syndrome
• Congenital unilateral aplasia of the pectoralis muscle
  
  
• Swyer-James Syndrome
• Unilateral hyperlucent lung that usually develops during childhood as a sequela of post-infectious bronchiolitis obliterans
  
  
• Pulmonary sling
• Anomalous origin of the left pulmonary artery may obstruct the right main bronchus leading to air-trapping
  
  
• Foreign-body aspiration (Obstructive Emphysema)
• May result in over aeration of affected side due to air trapping
  
  
• Bronchial atresia
• Collateral drift leads to overexpansion
  
  
• Congenital lobar emphysema
• Usually in neonate and most often in left upper lobe
  
  
• Technical issues
• Patient is rotated
• Side to which they are rotated my be more lucent
• Lateral decentering of tube
• Side toward which tube is centered is more lucent

 
Right Radical Mastectomy. The right hemithorax is more lucent (darker) than the left because the patient had previously undergone a right radical mastectomy in which the breast and the pectoralis muscles were removed. Note the multiple metallic clips from the surgery.

Unilateral Hyperlucent Lung in Children. E Wasilewska, EY Lee and RL Eisenberg. AJR, May 2012, Volume 198, Number 5