CT of double descending thoracic aorta in an adult female.

Persistent double dorsal aorta is a rare congenital anomaly of the descending aorta. It is an anomaly with two variants. The first type is characterized by complete separation of two dorsal aortae. The second type is a double-lumen descending aorta with a central dividing septum from the level just below the ductal ligament to the aortic bifurcation. We present a completely separated double dorsal aorta with a narrower right segment and the main left segment between the 6th and 10th thoracic vertebrae.