Radiological evaluation of internal abdominal hernias.

An internal abdominal herniation is the protrusion of a viscus through a normal or abnormal mesenteric or peritoneal aperture. Internal abdominal herniations can either be acquired through a trauma or surgical procedure, or constitutional and related to congenital peritoneal defects. Paraduodenal hernias are the most common type of internal abdominal hernias, accounting for over one-half of reported cases, and thus are a significant clinical entity. Other internal hernias include pericecal, transmesenteric, transomental, intersigmoid, supravesical hernias and herniation through the foramen of Winslow. Because internal abdominal herniations are rare, their diagnosis remains a challenge for both the clinician and the radiologist. Symptoms of internal abdominal herniations are nonspecific. We present our experience with the radiological evaluation of internal abdominal herniations and review the main radiologic findings on barium as well as computed tomography studies.