Figures
- Figure 1
Imaging findings in bronchiectasis. a) The arrow points to cylindrical bronchiectasis in the right lower lobe. The bronchi are dilated in relation to the pulmonary artery, producing a signet ring sign. There are also visible airways in the subpleural 1 cm of lung, demarcated by the dashed line. Airways are normally not visible peripherally and when seen are indicative of bronchiolectasis. b) Curved planar reformation shows lack of bronchial tapering in the right lower lung, in keeping with cylindrical bronchiectasis (arrow). This is the earliest and most sensitive sign of bronchiectasis. The aetiology of bronchiectasis in this patient was bronchiolitis obliterans after allogeneic haematopoietic stem cell transplantation. c) Different morphological types of bronchiectasis are often seen in the same patient. This patient had cylindrical bronchiectasis (arrow) with lack of bronchial tapering in the right lower lobe and varicose bronchiectasis in the right middle lobe (arrowhead). Tree-in-bud opacities, a common associated finding, are also noted (#).
- Figure 2
An important pitfall: mild reversible bronchial dilatation due to infection. This patient's clinical presentation gave concern for lower respiratory infection. a) Initial CT demonstrated bronchial dilatation with bronchial wall thickening (arrows) and areas of air space opacification (arrowhead), in keeping with bronchopneumonia. b) Subsequent imaging after antibiotic treatment revealed resolution of the air space opacification and a return of the bronchi to normal calibre. This does not reflect true bronchiectasis, which is irreversible.
- Figure 3
Post-radiation fibrosis. a) This patient had non-small cell lung cancer in the right lower lobe (not shown). The arrows show ground-glass opacities arising after radiation therapy, representing radiation pneumonitis. b) 4 months later there was interval development of post-radiation fibrosis with varicose bronchiectasis and volume loss in the treatment field (#).
- Figure 4
a) Varicose bronchiectasis (arrow) in a patient with sarcoidosis. Note the typical upper lobe location and associated reticulation and lung architectural distortion (#), suggesting fibrosis. b) Post-tuberculous bronchiectasis in a 90-year-old patient with a previous history of tuberculosis. The apical unilateral distribution is typical. c) Bronchiectasis in the right middle lobe and lingula in a 50-year-old female patient with a MAC infection. The anterior lung segment involvement is typical. d) Bronchiectasis in a different elderly female patient with severe MAC infection. Bilateral cylindrical bronchiectasis is noted as well as nodules (arrowhead), some of which have benign pattern central calcification. Consolidation with cavitation (arrow) is seen in the left lower lobe.
- Figure 5
a) An 88-year-old female patient with chronic obstructive pulmonary disease (COPD), dysphagia and frequent lower respiratory infections. The arrow points to aspirated contrast material in the trachea. b) CT in the same patient shows bilateral lower zone bronchiectasis (arrowheads) and tree-in-bud opacities (#). The presumed aetiology was chronic aspiration.
- Figure 6
a) Bronchiectasis in immunodeficiency. This patient had hyperimmunoglobulin E syndrome (Job's syndrome) and extensive bronchiectasis in the right lower lobe complicated by consolidation and an abscess formation (arrow). b) Ancillary findings with bronchiectasis. This patient had primary ciliary dyskinesia with widespread mucus plugging and adjacent consolidation, suggesting infection in the right lower lobe and middle lobe (arrowheads). The arrow points to bronchial wall thickening. Note the situs inversus.
- Figure 7
A 71-year-old male with a history of asthma presented with a 3-month history of productive cough. This patient had a positive sputum culture for Aspergillus and peripheral blood eosinophilia. Skin-prick test was positive for Aspergillus and serum IgE levels, including Aspergillus-specific IgE levels, were markedly elevated. a) Non-contrast-enhanced CT shows high-attenuation mucus plugging (>70 HU) within dilated central airways (arrow) and atelectasis typical for ABPA. b) Follow-up imaging after antifungal and steroid treatment revealed resolution of the mucus plugging and atelectasis with residual cylindrical bronchiectasis (arrow).
- Figure 8
a) CT pulmonary angiogram of a 70-year-old patient with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage four COPD on long-term oxygen therapy presenting with massive haemoptysis. Magnified sagittal reformation shows focal contour abnormality of a subsegmental pulmonary artery in keeping with a pseudoaneurysm associated with cylindrical bronchiectasis (arrowhead). The arrow points to adjacent air space opacities representing alveolar blood. b) Volume-rendered image of the pseudoaneurysm. The bleeding resolved with medical treatment and the pseudoaneurysm, bronchial wall thickening and air space opacities resolved on follow-up imaging. Case courtesy of Agusta Andresdottir (Landspitali University Hospital, Reykjavik, Iceland). c) Enlarged (>2 mm diameter) and tortuous bronchial arteries (arrow) in a different patient with severe bilateral bronchiectasis. This finding is not specific to bronchiectasis and is seen in disorders affecting the pulmonary circulation, and chronic infectious or inflammatory disease, as well as congenital conditions.
Tables
- Table 1
Diagnostic imaging findings in bronchiectasis
Imaging findings in bronchiectasis Bronchial dilatation: objectively assessed by broncho–arterial ratio >1:1 (or >1.5:1 for increased specificity) Lack of bronchial tapering >2 cm in length from airway bifurcation Visible peripheral airways within 1 cm vicinity of costal pleura or directly abutting mediastinal pleura Common associated findings suggestive of airway disease or inflammation Bronchial wall thickening Mucus plugging Tree-in-bud opacities - Table 2
Examples of other common causes of dilated bronchi
Other causes of dilated bronchi How to differentiate from bronchiectasis Normal ageing
High altitudeClinical context is key
Bronchial dilatation tends to be generalised and mild (broncho–arterial ratio <1.5:1)
No associated imaging findings of airway disease or inflammationRegional hypoxia Bronchial dilatation usually mild
Bronchi may actually be normal in diameter but have increased broncho–arterial ratio due to small pulmonary artery secondary to hypoxic vasoconstrictionBronchopneumonia Acute clinical symptoms
Comparison to prior studies
May require re-imaging
