A 77-year-old man presented with epigastric pain and nausea that lasted for 36 h. On arrival, he was hypotensive (100/70 mm Hg) and had low-grade fever (37.4°C). Physical examination showed generalised abdominal tenderness and a positive peritoneal sign. Plain abdominal radiography disclosed a double-wall sign (arrows), indicating pneumoperitonium (fig 1). Subsequent contrast-enhanced computed tomography confirmed the presence of free air accumulation and extravasation of oral contrast medium in the peritoneal cavity. On exploratory laparotomy, a 1-cm perforation above the prepyloric region was found. The patient underwent ulcerectomy and pyloroplasty, and had an uneventful recovery.

• Download figure
• Open in new tab
• Download powerpoint

Figure 1 Plain abdominal radiograph showing a double-wall sign (arrows).

Double-wall sign, also known as Rigler sign, indicates that both sides of the bowel wall can be visualised on a radiograph of the abdomen obtained with the patient in the supine position. The detection of pneumoperitonium by recognition of the double-wall sign is important in patients with acute abdomen, as urgent surgical attention may be required.1