Retroperitoneum

A pneumoretroperitoneum may be appreciated in each of the CT images presented above. In the left image, air is seen surrounding the right kidney, whereas the right image shows retroperitoneal air pushing the bowel centrally on the patient’s right side. [Courtesy of Dr. N. Jaffer]

Free air in the retroperitoneum makes retroperitoneal structures such as the psoas muscles and the kidneys visible. [Courtesy of Dr. N. Jaffer]