Cardiac-MRI demonstration of the ligamentum arteriosum in a case of right aortic arch with aberrant left subclavian artery.

Right-sided aortic arch with aberrant left subclavian artery (RAA/ALSC) is the second most common mediastinal complete vascular ring. Adult presentation of dysphagia lusoria due to a RAA/ALSC is uncommon with fewer than 25 cases reported in the world literature. The left lateral portion of this vascular ring is not a vessel, but an atretic ductus arteriosus, the ligamentum arteriosum, which has been identified in different cases as the major cause of tracheo-esophageal impingement. Surgical division of the ligamentum arteriosum allows the vessels to assume a less constricting pattern decreasing dysphagic symptoms. Clear visualization of the ligamentum arteriosum by diagnostic imaging has not been obtained in previously reported cases. We demonstrated, using magnetic resonance imaging, the location and the complete course of a left-sided ligamentum arteriosum in a patient with adult-onset dysphagia due to a RAA/ALSC with a small Kommerell's diverticulum, providing, during the same session, a complete assessment of both mediastinal vascular abnormalities and esophageal impingement sites.