Swyer-James (Macleod's) syndrome. Variations in pulmonary-bronchial arterial blood flow

Unilateral pulmonary artery agenesis: An unusual cause of unilateral ARDS

Unilateral pulmonary artery agenesis (UPAA) is a rare malformation that can present as an isolated anomaly or may be associated with certain congenital cardiac anomalies, such as tetralogy of Fallot, atrial septal defect, coarctation of aorta, right aortic arch, truncus arteriosus and pulmonary atresia. Clinical presentation is non-specific which makes the diagnosis elusive; chronic dyspnea, hemoptysis or recurrent infections are the most common manifestations. Patients may remain asymptomatic until adulthood. There is no definitive treatment for patients with UPAA. Acute respiratory distress syndrome (ARDS) is usually a bilateral disease, unilateral ARDS has been described after lung resection or trauma. We present a case of a 39 year-old woman who developed unilateral ARDS and was later diagnosed with isolated UPAA.

Imaging of small airways and emphysema

High-resolution chest computed tomography (CT) is one of the most useful techniques available for imaging bronchiolitis because it shows highly specific direct and indirect imaging signs. The distribution and combination of these various signs can further classify bronchiolitis as either cellular/inflammatory or fibrotic/constrictive. Emphysema is characterized by destruction of the airspaces, and a brief discussion of imaging findings of this class of disease is also included. Typical CT findings include destruction of airspace, attenuated vasculatures, and hyperlucent as well as hyperinflated lungs.

Mediastinal esophageal cyst causing unilateral hyperlucent lung

Unilateral emphysema secondary to bronchial obstruction by a foregut-derived mediastinal cyst is rare. Here we describe an infant with a unilateral hyperlucent lung due to compression on the left main bronchus by an esophageal cyst, visualized by chest computed tomography and magnetic resonance imaging. A chest roentgenogram and a perfusion scan presented the normalized left lung after resection of the cyst.

Pulmonary veno-occlusive disease in a unilateral hypertransradiant lung

Images

Transient unilateral hypoperfusion of the lung following mediastinoscopy

Two cases of pulmonary hypoperfusion occurring after mediastinoscopic examination were demonstrated on lung scans. In one case, this finding on the ninth day required a pulmonary angiographic study that yielded normal findings. Repeat lung scans were normal. We propose that localized mediastinal edema or bleeding after mediastinoscopic examination can produce defects of hypoperfusion, and we urge caution in the interpretation of lung scans up to nine days after mediastinoscopic examination.