Airway obstruction by right aortic arch with right-sided patent ductus arteriosus: demonstration by MRI.

An unusual cause of airway obstruction was demonstrated by MRI in two infants with congenital heart disease. The two infants experienced airway obstruction caused by a right aortic arch with right-sided patent ductus arteriosus. The diagnosis was established by MRI prior to surgery; angiography did not demonstrate the critical relationship between the large ductus and the airway. Axial, sagittal, and coronal MRI displayed the right arch, dilated ductus, and the compression of the proximal right bronchus and distal trachea by the ductus. Surgical findings confirmed the MR diagnosis. Thus, MRI can be used to localize the site of airway obstruction and to demonstrate unusual types of vascular anomalies.