Chilaiditi Syndrome – CXR and CT

Chilaiditi syndrome. This AP radiograph shows what appears to be very convincing free air below the right hemidiaphragm, however CT performed the same day confirms that this represents a normal variant called Chilaiditi syndrome, also known as colonic interposition. In these patients the colon is located between the liver and the diaphragm (arrow). It is asymptomatic but often mimics pneumoperitoneum.