Chest XRay in Pneumothorax


Chest XRay in Pneumothorax, Pneumothorax Imaging

  • Images
  1. Complete Pneumothorax
    1. lungPtxComplete_PA.jpg
  2. Reexpansion pulmonary edema following Chest Tube placement
    1. lungPtxCompleteReExpansionPulmonaryEdema.jpg
  1. Findings
    1. Medial
      1. Thin, line representing visceral pleura
    2. Interspace
      1. Radiolucent band without lung markings
      2. Air-fluid level may be present (assume Hemothorax in Trauma)
    3. Lateral
      1. Chest wall
  2. Posteroanterior (PA) Standard View - Inspiratory
    1. Best overall XRay to view to identify Pneumothorax
    2. Obtain upright image, as supine Chest XRay is unreliable and likely to yield a False Negative study
    3. End Expiratory views were used in past to enhance Pneumothorax
      1. Theoretically should enhance the Pneumothorax which is constant, by reducing the air in lung
      2. Not recommended, as they add little additional to that seen on inspiratory films
  3. Lateral decubitus view (affected side up)
    1. May identify a small Pneumothorax suspected but not seen on upright Chest XRay
  4. Criteria for large Pneumothorax
    1. British Thoracic Society
      1. Band or rim around lung margin of 2 cm or greater (50% pleural volume)
    2. American College Chest Physicians
      1. Apex to Cupola distance >3 cm (15-20% of pleural volume)
  5. Efficacy
    1. Test Sensitivity: 85% (compared with CT Chest)
  6. False Positives
    1. Pulmonary Bleb (COPD) - may require CT chest to distinguish
    2. Skin folds
    3. Scapula border
  • Imaging
  • Advanced
  1. Ultrasound chest
    1. See Lung Ultrasound for Pneumothorax (Sliding Lung Sign)
    2. Test Sensitivity 94% and Test Specificity 100% for Pneumothorax
  2. CT Chest
    1. Gold standard in Pneumothorax
    2. Indicated where Chest XRay cannot distinguish bleb in COPD from Pneumothorax
    3. In those with Secondary Spontaneous Pneumothorax due to blebs, contralateral blebs are seen in >50% of cases
      1. These contralateral blebs have a 25% chance of future secondary Pneumothorax
    4. May identify a clinically insignificant Pneumothorax that would resolve without treatment