Localized |
Foreign body aspiration |
Intraluminal obstruction (eg, foreign body, mucus plug, tumor) |
Congenital abnormality (intralobar bronchopulmonary sequestration, bronchial stenosis, bronchomalacia, tracheal bronchus) |
Extraluminal compression (lymphadenopathy [eg, tuberculosis], vascular compression, or cardiomegaly) |
Past severe local pneumonia |
Chronic localized atelectasis or infection (eg, chronic right middle lobe syndrome, mucus plugging) |
Generalized |
Upper lobe predominance |
Cystic fibrosis* |
Aspiration syndrome in nonambulating children |
Sarcoidosis |
Central airways |
Allergic bronchopulmonary aspergillosis |
Mounier-Kuhn syndrome (may also affect lower lobes if repeated infections) |
Lower lobes predominance |
Hypogammaglobulinemia (and other inborn errors of immunity) |
Chronic aspiration in ambulating children |
Interstitial pneumonia |
Idiopathic |
Middle lobe and lingual predominance |
Primary ciliary dyskinesia |
Atypical mycobacterial infection |
HRCT: high-resolution computed tomography; MDCT: multidetector computed tomography.
* In chest radiograph-based studies, cystic fibrosis has an upper lobe predominance, but this is not a consistent finding in CT-based studies[2,3].Adapted from: Javidan-Nejad C, Bhalla S. Bronchiectasis. Radiol Clin North Am 2009; 47:289.