Chest Imaging

Pulmonary artery agenesis

(also called pulmonary artery interruption), stenosis or focal interruption of the pulmonary artery. Unilateral pulmonary artery agenesis is a misnomer. The best description from a radiological viewpoint is occult pulmonary artery. It can be isolated or associated with cardiovascular anomalies, mainly in childhood; tetralogy of Fallot, type I right aortic arch, septal defects and patent ductus arteriosus. The radiological signs are: small lung, absence of hilar pulmonary artery, moderate hyperlucency without air trapping. The increased systemic collateral supply may attenuate the hyperlucency and create a mixed micronodularreticular pattern and costal erosions; can easily rupture in adulthood, causing haemoptysis. The pretherapeutic evaluation consists of transoesophageal echocardiography, CT and MR angiography and sometimes pulmonary and systemic angiography. In patients in whom an anastomosis with the pulmonary trunk is suspected, the radiological aim is to determine the precise proximal intra- or extrapericardial site and the length of interruption. Embolotherapy can be the only treatment in adults with haemoptysis. The association of a type I right aortic arch with hyperlucent hypovascular left lung is virtually pathognomonic of a left occult pulmonary artery. Noninvasive or invasive angiographies may show a ductus infundibulum at the origin of the left innominate artery.

JR - MRJ