Case No 016 : This is a supine abdominal X-ray what is your findings ?What are the main radiological signs in plain abdominal film ?

This is a case of pneumoperitoneum 

What are the main radiological signs in plain abdominal film ?

The plain-film radiograph of the abdomen showed several signs of free intraperitoneal gas. These included air accumulation in the right upper quadrant (the subphrenic area and ventral surface of the liver) ; the falciform-ligament sign, visible as a longitudinal linear density on the ventral surface of the liver ; the ligamentum teres sign, visible as a linear density running along the inferior edge of the falciform ligament ; and Rigler's sign, the visualization of air on both sides of the bowel