The chest x-ray shows a convex opacity overlapping the right upper mediastinum which may be due to dilated oesophagus. Small gastric bubble with aerated splenic flexure. Both lungs are clear. No pleural effusion is seen.
On barium swallow, the oesophagus is dilated with tertiary contractions and acute tapering at the lower oesophageal sphincter, producing a "bird's beak" appearance.