Pneumoperitoneum Flashcards
Pneumoperitoneum
Radiology: pneumoperitoneum
An erect chest x-ray is a useful investigation in patients with an acute abdomen as it may demonstrate free air in the abdomen (pneumoperitoneum) - an abnormal finding suggestive of a perforated abdominal viscus (e.g. a perforated duodenal ulcer).
SEE PASSMED CXR PNEUMOPERITONEUM
Rigler’s sign (double wall sign) may be seen on an abdominal film.
CT is now the preferred method for detecting free air in the abdomen.
Pneumoperitoneum - AXR
SEE PASSMED AXR PNEUMOPERITONEUM
Abdominal x-ray demonstrates numerous loops of small bowel outlined by gas both within the lumen and free within the peritoneal cavity. Ascites is also seen, with mottled gas densities over bilateral paracolic gutters. In a normal x-ray only the luminal surface (blue arrows) should be visible outlined by gas. The serosal surface (orange) should not be visible as it is normally in contact with other intra-abdominal content of similar density (other loops of bowel, omentum, fluid). In this case gas abuts the serosal surface rendering it visible. As this film has been obtained supine (note absence of air-fluid levels), ascites pools in the paracolic gutters, with fluid mixed in with gas bubbles.
