Discussion of Bronchiectasis
- Defined as localized irreversible dilatation of part of the bronchial tree
 Etiologies of Bronchiectasis
- Infection: Typical organisms include Klebsiella species, Staphylococcus aureus, Mycobacterium tuberculosis, Mycoplasma pneumoniae, nontuberculous mycobacteria, Mycobacterium avium-intracellulare complex, measles, pertussis, influenza, respiratory syncytial virus, herpes simplex virus, and certain types of adenovirus.
- Bronchial obstruction: Obstruction occurs as a result of endobronchial tumors, broncholithiasis, bronchial stenosis resulting from infections, encroachment of hilar lymph nodes, and foreign body aspiration.
- Cystic fibrosis
- Primary ciliary dyskinesia
- Allergic bronchopulmonary aspergillosis
- Immunodeficiency states
- Congenital anatomic defects
- Pulmonary sequestration
- Williams-Campbell syndrome (congenital cartilage deficiency)
- Mounier-Kuhn syndrome (tracheobronchomegaly)
- Swyer-James syndrome (unilateral hyperlucent lung)
- a1-Antitrypsin deficiency
- Lung and bone marrow transplants
- Rheumatoid arthritis and Sjögren syndrome
- Traction bronchiectasis associated with pulmonary fibrosis
 Classification of Bronchiectasis
- Cylindrical: Bronchi have a uniform caliber, they do not taper, and they have parallel walls.
- Cystic or Saccular: Severe form of bronchiectasis. The involved bronchi are cystlike in appearance and extend to the pleural surface. Air-fluid levels are commonly present.
- Varicose: Relatively uncommon. The bronchi have a beaded appearance with a dilated bronchus and interspersed sites of relative narrowing.
 Imaging Findings for Bronchiectasis
 Plain film
- Parallel line opacities (tram tracks) caused by thickened dilated bronchi
- Tubular opacities caused by dilated fluid-filled bronchi
- Crowding of pulmonary vascular markings from the associated loss of volume, usually caused by mucous obstruction of the peripheral bronchi
- Bronchial diameter may be greater than that of the adjacent artery.
- Lack of bronchial tapering (the same diameter as the parent branch for >2 cm).
- Bronchi may be within 1 cm of costal pleura.
 See Also
 External Links
 References for Bronchiectasis
- Isaac Hassan. E-medicine radiology article