Bronchiectasis (summary)

This is a basic article for medical students and other non-radiologists

Bronchiectasis refers to permanent dilatation of the airways secondary to chronic inflammation or infection. It is the common pathological response of bronchi to a variety of congenital and acquired conditions.

Reference article

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

Summary

• epidemiology
  • ​​more prevalent in females and older age groups
    • 60% of UK diagnoses made in patients over 70
  • triggering disease may be congenital or acquired
• presentation
  • chronic productive cough with thick, foul-smelling sputum
  • recurrent chest infections
  • hemoptysis 
  • shortness of breath
  • wheeze
  • examination findings:
    • general - clubbing (rare)
    • auscultation - coarse crackles, scattered wheeze
• pathogenesis
  • ​a combination of chronic inflammation/infection and impaired bronchial clearance damages the airways
  • progressive destruction of lung tissues
    • widened airways with scarred and thickened walls
    • trapped mucus harbors pathogens
• etiology
  • ​post-infectious conditions
    • tuberculosis
    • bacterial pneumonia
    • measles
  • congenital conditions
    • cystic fibrosis (up to 50% of cases)
    • primary ciliary dyskinesia (Kartagener syndrome)
    • primary immunodeficiencies 
    • alpha-1-antitrypsin deficiency
  • other
    • airway obstruction (foreign body/malignancy)
    • traction bronchiectasis (pulmonary fibrosis)
    • associated illnesses - COPD, IBD, rheumatoid arthritis, SLE
  • idiopathic
• investigation
  • chest x-ray
  • high-resolution CT
  • sputum culture (esp. during exacerbation)
  • pulmonary function tests (reduced FEV1)
  • specific tests to investigate cause
    • e.g. sweat sodium measurement (CF) or immunoglobulins
• treatment
  • goals are to prevent infections and control complications
  • conservative
    • smoking cessation
    • respiratory physiotherapy and postural drainage
    • pneumococcal vaccine, annual influenza vaccine
  • medical
    • prompt antibiotic treatment for exacerbations
      • long-term prophylactic antibiotics may be required in patients with frequent recurrences
    • bronchodilator therapy
      • beta agonists and inhaled corticosteroids
  • surgical
    • only for a small minority of patients with localized disease

Radiographic features

Plain radiograph

Chest x-rays are usually insufficient in the diagnosis and management of bronchiectasis. May be normal or may show dilated bronchi with thickened walls (tram-track sign). An air-fluid level may be seen in severe cystic bronchiectasis.

CT

High-resolution CT is the gold standard for diagnosis. Provides a better visualization of the classical airway dilatation and bronchial wall thickening (tram-track) in bronchiectasis. Enlarged airways display a signet-ring sign in cross-section with their accompanying pulmonary artery. Cysts may also be visualized.