Right aortic arch on X-ray chest PA

Right aortic arch on X-ray chest PA

Side of aortic arch is identified by the tracheal indentation by the arch. The indentation is seen on the right side of the tracheal air column in right aortic arch. The upper thoracic descending aorta will be seen on the right side of the spine in right aortic arch.

Agata and colleagues analysed large University Radiology databases of 11,690 CT scan examinations of the chest area, 19,623 CT scans of the brain-supplying vessels, and 1,863 MRI examinations of the heart and aortic arch or brain-supplying arteries.  They could find only nine cases of type I right aortic arch and 11 cases of type II right aortic arch [1]. Eight of the 11 type II right aortic arch had associated Kommerell’s diverticulum.

Right aortic arch is noted in 0.05 to 0.1% in radiological series [1]. Right aortic arch has been classified into 3 types by Edwards:

Type I: Right aortic arch with aberrant left subclavian artery

Type II: Right aortic arch with mirror image branching

Type III: Right aortic arch with isolation of the left subclavian artery

In right aortic arch with aberrant left subclavian artery, it may arise from a remnant of the left dorsal aortic root known as Kommerell’s diverticulum.

Reference

1. Agata Arazińska, Michał Polguj, Konrad Szymczyk, Magdalena Kaczmarska, Łukasz Trębiński, Ludomir Stefańczyk. Right Aortic Arch Analysis – Anatomical Variant or Serious Vascular Defect? BMC Cardiovasc Disord. 2017 Apr 19;17(1):102.