Cystic Fibrosis

  • Etiology: 1) thick exocrine secretions – > thick mucous -> decreased mucocilliary clearance -> bacterial colonization -> bronchiectasis 2) thick exocrine secretions – > thick mucous -> mucous plugging -> ball valving -> air trapping
  • CXR: follow chronic changes, surveil for new pneumonia + pulmonary hemorrhage
  • CT: inspiratory – look for bronchiectasis – to diagnose bronchiectasis on CT need diameter of bronchus > diameter of adjacent pulmonary artery, expiratory – look for air trapping
  • Imaging: sinusitis
  • Complications: pulmonary hemorrhage from bronchial artery hypertrophy caused by infection as focal infection can erode into artery, pulmonary infection (colonized by Haemophilus influenzae, Staphlococcus aureus, Pseudomonous aeruginosa (most common)), bronchiectasis, meconium ileus, meconium peritonitis, distal intestinal obstruction syndrome / meconium ileus equivalent, malabsorption, infertility

Cases of Cystic Fibrosis

CXR of lung abscess
CXR shows a round cavitary lesion with an air-fluid level in the left upper lobe.
CT of bronchiectasis
Axial CT without contrast of the chest shows extensive bronchiectasis throughout the lungs.
CXR and angiogram of pulmonary hemorrhage in cystic fibrosis
CXR (left) shows chronic changes of cystic fibrosis. Bronchial artery angiogram (right) shows hypertrophy of the right-sided bronchial arteries.