[Magnetic resonance imaging in the diagnosis of retrotracheal pulmonary artery].

The authors report the case of a 3-month-old infant with a history of interventricular septal defect with pulmonary arterial hypertension. This child had pulmonary symptomatology (dyspnea, recurrent bronchitis, acute attacks of asphyxia) which it was possible to link to a retrotracheal left pulmonary artery by magnetic resonance imaging (MRI). Classical investigations (upper GI barium series and chest X-ray) were suggestive of a bronchogenic cyst type abnormal pulmonary structure. Angiography confirmed the MRI diagnosis. In this case the infant also had tracheal lesions (lower tracheal hypoplasia) which required further evaluation by fibroscopy and bronchography. Thus MRI shows itself to be a useful investigation in the study of basic vascular abnormalities.