Discussion
Diagnosis With Brief Discussion
- Diagnosis
- Unilateral pulmonary artery interruption. (Pulmonary artery agenesis, unilateral absence of a pulmonary artery)
- Radiologic Findings
- Chest radiograph shows volume loss of left lung with mediastinal shifting to the left side. Right lung is hyperinflanted. Contrast-enhanced CT scan shows complete absence of left pulmonary artery with hypoplastic left lung and right aortic arch. Systemic collateral formation from bronchial, intercostal and inferior phrenic arteries is also noted. CT scan obtained with lung window setting shows multiple linear opacities perpendicular to the pleural surface that correspond to traspleural systemic vessels. There is no evidence of cardiomegaly, pulmonary hypertension and TOF.
- Brief Review
- Proximal interruption of the right or left pulmonary artery is an uncommon developmental anomaly. Blood is supplied to the lung through collateral systemic vessels, mainly bronchial arteries but also transpleural branches of the intercostal, internal mammary, subclavian, and innominate arteries. Interruption of the left pulmonary artery is usually associated with a right aortic arch and other congenital cardiovascular anomalies.
Chest radiographs typically show a volume loss in the hemithorax. In patients with enlarged intercostal and transpleural arteries, fine linear opacities are seen at the periphery of the lung. On CT scans, the mediastinal portion of the affected pulmonary artery may be completely absent or may terminate within 1 cm of its origin. Serrated thickening of the pleura and subpleural parenchymal bands also may appear on CT scans and may be attributable to direct anastomosis of transpleural collateral vessels with peripheral branches of the pulmonary artery.
In the differential diagnosis, acquired causes of pulmonary obstruction (chronic thromboembolic occlusion, Takayasu arteritis, and mediastinal fibrosis) must be ruled out.
- References
- Castaner E, Gallardo X, Rimola J et al. Congenital and acquired pulmonary artery anomalies in the adult: radiologic overview. Radiographics 2006; 26:349-371
- Keywords
- vascular, congenital,