Presentation
Abdominal distension
Patient Data
On the erect image a small volume of pneumoperitoneum is detected under the right hemidiaphragm. On the supine image, there is an excellent example of Rigler's sign in the left upper quadrant, again indicating pneumoperitoneum.
Supine abdominal radiograph with the outer wall (serosal aspect) of a bowel loop visible in the left upper quadrant. This is an example of Rigler's sign and implies that there must be free air within the peritoneal cavity otherwise this interface would not be visible.
Case Discussion
Typical appearance of free intraperitoneal gas (pneumoperitoneum) on erect and supine abdominal radiographs including an excellent example of Rigler's sign.