Presentation
Respiratory depression
Patient Data
Reduced volume of the left hemithorax with mediastinal shift to left.
Small left hilum and peripheral oligemia.
Hyperlucent left lung. Elevated left hemidiaphragm, left hilum and mediastinal shift to the left are suggestive of lung volume reduction. There is a compensatory hyper expansion of the right lung.
The left pulmonary artery is hypoplastic and shows peripheral oligemia. Subtle air trapping is evident in expiratory images.
Varicoid bronchiectatic changes are seen in the apical-basal segment of the left lower lobe. There are scattered centrilobular and tree in bud nodules in the periphery of both lower lobes in keeping with bronchitis/ bronchiolitis type lower respiratory tract infection.
- axial HRCT: peripheral oligemia, compared with right lung
- coronal HRCT: reduced lung volume of left hemithorax
- coronal non-contrast CT: hypoplastic left pulmonary artery
Case Discussion
The main reason for Swyer-James-MacLeod syndrome is recurrent childhood viral respiratory tract infections leading to post-infectious bronchiolitis. As a consequence of this, impairment of vascular and pulmonary development of the affected areas may occur. The pulmonary artery on the affected side is hypoplastic and hypoperfusion of the lung parenchyma causes hyperlucent unilateral lung syndrome.
The disease may follow a varying degree of bronchiectasis in the affected segments.