Radiological imaging of Macleod syndrome.

Dr/ ABD ALLAH NAZEER. MD.

Swyer-James syndrome (SJS), also known as Swyer-James-MacLeod syndrome and Bret syndrome, is a rare lung condition that manifests as unilateral hemithorax lucency as a result of post-infectious obliterative bronchiolitis. EpidemiologyThe condition typically follows a viral respiratory infection such as adenoviruses or Mycoplasma pneumoniae infection in infancy or childhood. Radiographic featuresPlain radiographIt is generally characterized on radiographs by a unilateral small lung with hyperlucency and air trapping.CTCT shows the affected lung as being hyperlucent with diminished vascularity. The size of the majority of the affected lobes is smaller, although occasionally they can be normal. There is usually no anteroposterior gradient attenuation. Bronchiectasismay be present although this is not a universal finding.

Nuclear medicineQuantitative ventilation/perfusion lung scan shows a photopaenic area in the affected aspect.Magnetic Resonance ImagingIn Swyer-James syndrome, the pulmonary vessels of the affected lung appear smaller than normal on magnetic resonance imaging (MRI) scans. Peripheral branches of the pulmonary vessels do not develop, and vasculature is arrested at the stage at which the infection occurred. AngiographyIn patients with Swyer-James syndrome, the pulmonary artery and its branches are small and hypoplastic on the involved side. Collateral vessels may be present, but they are unusual.However, acquired hypoplastic lung cannot be differentiated on angiography from congenital hypoplasia of the lung. Swyer-James syndrome is also similar in appearance to lobar emphysema and hypoplastic pulmonary artery.

Macleod syndrome and the left lung is hyperlucent and is overexpanded. The right lung is small. The patient was asymptomatic at this time.

Macleod syndrome and the left lung is hyperlucent and is overexpanded. The right lung is small.

Swyer-James (MacLeod) syndrome.

Adult diagnosis of Swyer-James-MacLeod syndrome.

(a) Chest X-ray shows a hyperlucent and over-expanded left lung with a small right lung with left lower lobe limitation, ‘long arrows’ in (a).

Anterior–posterior plain film of chest (a) demonstrating diminished right thoracic cage volume and diminished right lung volume compared to the left. CT of chest with IV contrast (b) illustrating hyperlucency of the right lung with diminished right lung vascularity and volume. There is right upper, middle, and lower lobe bronchiectasis. Pulmonary ventilation study (c) following inhalation of technetium 99m DTPA aerosol illustrates increased tracer accumulation in right upper lung, with only moderate accumulation in the right middle lung. The right lower lung shows large fields without appreciable tracer accumulation. The left lung produces a normal response of homogenous tracer accumulation throughout. Pulmonary perfusion study (d) following IV administration of technetium 99 MAA demonstrates heterogeneous distribution of tracer in the right lung which matches that of the ventilation study. There is normal homogenous tracer distribution throughout the left lung

Computed tomography (a) hyperlucency of nearly all the left upper lobe due to diminished vasculature with a hypoplastic left pulmonary artery (arrow).

Adult diagnosis of swyer-james-macleod syndrome.

Macleod syndrome: a. Chest X-rays showing reduced left lung volume and herniation of hyperinflated right lung (arrow). b, c. Axial CT scan and min IP coronal reconstruction reveal hyperlucency of left lung and airways patency. d. Contrast enhanced MIP coronal reconstruction reveal left pulmonary arteries have strikingly decreased caliber.

Macleod syndrome: Thoracic computerize tomography demonstrating small sized left pulmonary artery (yellow arrow) and air trapping, areas of bronchiectasis and reduced vascularity in the left lower lobe.

 Macleod syndrome: Thoracic computerize tomography on the mediastinal window showing hypoplasia of the left pulmonary artery. Axial image on the parenchymal window showed hyperinflation and the absence of peripheral vascular structures in the left lower lobe.

Hypertrans-radiant hemithorax (MacLeod/Swyer–James syndrome) in an 18-year-old woman. The plain chest radiograph (a) shows increased transradiancy of the left lung with significantly diminished vascularity. The coronal slices (b – d) clearly demonstrate diminished vascularity (b, MIP), shrinkage (c), and bilateral bronchi-ectasis (d).

Lung perfusion scintiscan detects no perfusion to left lung.

Chest radiograph and CT Scan shows reduction in perfusion and volume of left lung with mediastinal shift to the same side.

Swyer-James Syndrome. A. Chest radiograph demonstrates hypolucent left lung. B. Magnetic resonance angiography demonstrates small and decreased pulmonary vasculature on the left side. LPA, left pulmonary artery.

Swyer James Macleod Syndrome.

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