Imaging of the pediatric peritoneum, mesentery and omentum.

The normal peritoneal structures, including the mesenteries and the omenta, are only a few cell layers thick and are visible on imaging based upon the tissues (e.g., fat) and structures (e.g., blood vessels and lymph nodes) contained within them. These structures become more visible and change in appearance when involved by pathological processes. In this pictorial essay, we discuss the normal anatomy of the various abdominopelvic peritoneal structures and illustrate numerous developmental and acquired diagnoses that involve these structures in the pediatric and young adult population.