Figure 1
Conventional chest radiograph
shows a hyperlucent left hemithorax and small left hilum. Rarefaction of the pulmonary vessels is noted.
Clinical History
The radiological findings of a hyperlucent lung with air trapping, bronchiectasis and a hypoplastic pulmonary artery are typical for the Swyer-James syndrome (MacLeod's syndrome).
Imaging Findings
The patient presented in the emergency room because of left-sided chest pain, probably of musculo-skeletal origin. The conventional chest radiograph demonstrated a hyperlucent left lung, with evidence for hypoperfusion. CT scan was performed to rule out pulmonary embolism.
Conventional chest radiograph (PA-view) shows a hyperlucent left hemithorax and small left hilum.
Rarefaction of the pulmonary vessels is noted. Contrast-enhanced CT scan of the thorax shows hypoplastic left pulmonary artery, compared to the right side. No pulmonary embolism is seen.
High resolution CT scan of the lungs demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left. Areas with cystic bronchiectasis in the posterobasal segment of the left lung are also seen. Scans taken during expiration demonstrate a slight mediastinal shift to the right. No change in density nor volume of the left lung compared to the inspiratory scan is noted.
The radiological findings of a hyperlucent lung with air trapping, bronchiectasis and a hypoplastic pulmonary artery are typical for the Swyer-James syndrome (MacLeod's syndrome).
Conventional chest radiograph (PA-view) shows a hyperlucent left hemithorax and small left hilum.
Rarefaction of the pulmonary vessels is noted. Contrast-enhanced CT scan of the thorax shows hypoplastic left pulmonary artery, compared to the right side. No pulmonary embolism is seen.
High resolution CT scan of the lungs demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left. Areas with cystic bronchiectasis in the posterobasal segment of the left lung are also seen. Scans taken during expiration demonstrate a slight mediastinal shift to the right. No change in density nor volume of the left lung compared to the inspiratory scan is noted.
The radiological findings of a hyperlucent lung with air trapping, bronchiectasis and a hypoplastic pulmonary artery are typical for the Swyer-James syndrome (MacLeod's syndrome).
Discussion
Swyer-James syndrome is characterised by hyperlucent lung with air trapping. The cause seems to be a viral infection of the airways in the early childhood. The bronchiolitis prevents the normal development of the peripheral airways and leads to a reduced pulmonary perfusion. Therefore hypoplasia of the pulmonary arteries is another typical finding is this syndrome. The resulting postinfectious bronchiolitis obliterans causes the air trapping and bronchiectasis which are often found in patients with the syndrome. Bronchiectasis can lead to recurrent pulmonary infections and therefore influence the prognosis of the disease. According to the literature, patients without bronchiectasis or with cylindrical bronchiectasis have a lower incidence of pneumonias and therefore a better prognosis than those with cystic bronchiectasis. The extent and the type of bronchiectasis are best demonstrated with a high-resolution CT. In- and expiratory scans clearly depict the amount of air trapping.
Differential Diagnosis List
Swyer-James syndrome (MacLeod's syndrome)
Final Diagnosis
Swyer-James syndrome (MacLeod's syndrome)
References
[1] Lucaya J, Gartner S, Garcia-Pena P et al. Spectrum of manifestations of Swyer-James - MacLeod Syndrome. J Comput Assist Tomogr 1998; 22: 592-597. (PMID: 9676450)
[2] Marti-Bonmati I, Perales FR, Catala F et al. CT findings in Swyer-James Syndrome. Radiology 1989; 172: 477-480. (PMID: 2748829)
[3] Moore ADA, Godwin JD, Dietrich PA et al. Swyer-James Syndrome: CT findings in Eight Patients. AJR 1992; 158: 1211-1215. (PMID: 1590109)
Case information
| URL: | https://eurorad.org/case/1437 |
| DOI: | 10.1594/EURORAD/CASE.1437 |
| ISSN: | 1563-4086 |
Figure 2
Contrast-enhanced CT scan of the thorax
shows hypoplastic left pulmonary artery, compared to the right side. No pulmonary embolism is seen.
Figure 3
High resolution CT scan of the lungs
demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left.
demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left.
Areas with cystic bronchiectasis inthe posterobasal segment of the left lung are also seen. Scans taken during expiration demonstrate a slight mediastinal shift to the right.
Conventional chest radiograph
shows a hyperlucent left hemithorax and small left hilum. Rarefaction of the pulmonary vessels is noted.
Contrast-enhanced CT scan of the thorax
shows hypoplastic left pulmonary artery, compared to the right side. No pulmonary embolism is seen.
High resolution CT scan of the lungs
demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left.
demonstrates on the scans taken during breath hold in inspiration a reduced density of the lung parenchyma on the left.
Areas with cystic bronchiectasis inthe posterobasal segment of the left lung are also seen. Scans taken during expiration demonstrate a slight mediastinal shift to the right.