Barium swallow demonstrates a concentric attenuation of the barium contrast in the superior mediastinum.
The patient was then scanned with dynamic contrast administration, with an esophageal boogie in situ (to better delineate the esophagus).
CTA of the chest obtained with a boogie (light-yellow cylinder) in esophagus (trachea anterior to it not seen) demonstrates a mirror image aortic arch with aberrant left subclavian artery (order of vessel origin from the aortic arch: left CCA, right CCA, right subclavian, left subclavian) which passes behind the esophagus creating an incomplete ring.
Case Discussion
Incomplete vascular ring, in this case caused by a right sided aortic arch with mirror anatomy and an aberrant left subclavian artery. The mirror anatomy is a marker for likely co-existing congenital heart disease (not sure of any such defects in this patient).