Radiologic diagnosis
Radiologic Diagnosis
43-year-old man
Asthmatic with progressive dyspnea
Normal cardiac function
-------------------------------------------------------------------------------Answer
Swyer-James (Macleod) Syndrome
Chest radiograph
- Hyperlucency of the left lung with associated reduced vascularity
and decreased lung volume.
- High-resolution CT (HRCT).
Bronchiectasis, decreased attenuation and vascularity.
Swyer-James (McLeod) syndrome is a condition characterized by
bronchiolitis obliterans involving predominantly one lung or, less
commonly, a lobe or segment. It typically follows an early childhood
infection, most commonly a viral pneumonia.
The characteristic radiographic manifestations include:
1.
2.
3.
4.
5.
Hyperlucency of the involved lung or lobe.
Decreased vascularity.
Small hilum.
Decreased volume of the involved lung or lobe.
Air trapping on expiratory radiographs.
High resolution CT demonstrates similar findings as the radiograph
but is superior to radiography in demonstrating the presence of
bronchiectasis in the involved lung. High resolution CT also frequently
shows mild abnormalities in the contralateral lung.
The patients are usually asymptomatic. Symptoms when present
include dyspnea on exertion and recurrent infection.
The main differential diagnosis on the radiograph is with central
bronchial obstruction by a tumor or foreign body. Central bronchial
obstruction can be readily excluded with CT or bronchoscopy. The
presence of air trapping on expiratory radiography or CT allows
distinction of Swyer-James syndrome from congenital hypoplastic
lung and other congenital vascular causes of unilateral decreased
vascularity.
-------------------------------------------------------------------------------Bibliografia
1. Armstrong P, Wilson AG, Dee P, Hansell DM. Imaging of Diseases
of the Chest. 2nd edition. Mosby. St. Louis 1995
2. FraserRS, Müller NL, Colman N, Paré PD. Diagnosis of Diseases
of the Chest. 4th edition. WB Saunders Company. Philadelphia 1999
Webb WR, Muller NL, Naidich DP.High-Resolution CT of the Lung.
3rd edition. Lippincott-Raven. Philadelphia
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