Posterior marking on Ba column in Ba swallow study is caused by?: (A) Aoic knuckle, (B) Left atrium, (C) Aberrant right subclan aery, (D) Pulmonary aery sling
Answer is C. C i.e. Aberrant right subclan aery An aberrant right subclan aery arises from the aoic arch distal to the origin of left subclan aery, and passes upwards & to the right behind the oesophagus. This gives rise to a classical smooth, oblique indentation on posterior wall of barium filled oesophagusQ.