Imaging Case of the Week 210 Answer

The erect chest x-ray shows a continuous diaphragm sign, suggestive of pneumoperitoneum.

continuous diaphragm sign

The supine abdominal x-ray from the same patient shows Rigler’s sign or the double wall sign. Rigler’s sign is seen when the intraperitoneal free air outlines both sides of the bowel wall.

Rigler's sign