LearningRadiology - Bronchiectasis

Bronchiectasis

• Pathologic dilation of the medium sized airways

• Proximal bronchiectasis is characteristic of allergic bronchopulmonary aspergillosis (ABPA)

• Classical clinical triad: chronic cough, excess sputum production and repeated infection

Pathogenesis

• Three major causes are: obstruction, infection and traction

• Bronchiectasis is common when there is prolonged partial obstruction, e.g. slow-growing neoplasms, foreign bodies

• Infection is most important cause of bronchiectasis

• Bronchial wall destruction occurs in infection

• Traction comes from a force, usually due to increased elastic recoil in the surrounding lung, which pulls the bronchus and dilates it

Location

• Bronchiectasis from viral or pyogenic infections is usually at the bases

• Tuberculous bronchiectasis is usually at the apices

• Diffuse bronchiectasis

§ Impaired mucus clearing e.g. cystic fibrosis and Kartegeners

§ ABPA

§ Chronic diffuse airways disease (chronic bronchitis, asthma, bronchiolitis obliterans

§ Immune deficiency states

X-ray

• “Tramlines” or “honeycombing” represents dilated, thickened bronchial walls

• Volume loss due to destruction of lung tissue

• Multiple small nodular densities from plugged alveoli

• Signet ring appearance on CT: normally, the vessel is larger than the corresponding bronchus. In bronchiectasis, the bronchus is larger than the corresponding vessel

• Lack of bronchial tapering

• Non uniform bronchial dilation

• Bronchial wall thickening

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