Colonic interposition between the liver and diaphragm can present as pseudopneumoperitoneum on plain film and is known as Chilaiditi sign. Pneumoperitoneum and subphrenic abscess should be considered in the differential, however. Radiographic diagnosis is made by an elevated right hemidiaphragm, visible air in the colon under the diaphragm, and a depressed superior edge of the liver. This variant anatomy in a patient with abdominal pain, nausea, vomiting, or respiratory distress is known as Chilaiditi syndrome, which may be rarely complicated in cases of volvulus or perforation. 

This case was submitted with supervision and input from:

Soni C. Chawla, M.D.
Associate Professor
Department of Radiological Sciences
David Geffen School of Medicine at UCLA
Olive View - UCLA Medical Center