Rigler sign
AbdomenRadiograph
Both the inner (luminal) and outer (serosal) walls of a bowel loop are clearly visible on a supine abdominal radiograph.
What it means
Pneumoperitoneum, with free intraperitoneal gas outlining the outer bowel wall.
Mechanism
Free gas on the peritoneal surface plus intraluminal gas sandwiches the bowel wall, rendering both sides of it visible (the double-wall sign).
Associated conditions
- Perforated viscus
- Post-operative pneumoperitoneum
- Perforated peptic ulcer
- Bowel ischaemia with perforation
Pearls
- Also called the double-wall sign; it requires a substantial volume of free gas.
- An erect chest film showing subdiaphragmatic air remains the more sensitive first test.
References
- Radiopaedia: Rigler sign
For educational use only. This dictionary is a study aid and reference, not a diagnostic tool, and must not be used to guide clinical decisions or patient care. Imaging appearances vary; always correlate with the full clinical picture and confirm with a qualified radiologist.