CT of the mesocolon. Part 1. Anatomic considerations.

To define the anatomy of the mesocolic attachment of the colon as seen on computed tomographic (CT) scans, the authors reviewed CT scans of patients with diseases of the colon and the pancreas and found that disease processes in these areas usually spread along the mesocolon. The plane of the mesocolon can be distinguished from the mesentery of the small bowel by identifying the vessels in the mesocolon that serve as its landmarks. These vessels include the ileocolic vessels and right colic vessels for the ascending mesocolon, the middle colic vessels for the transverse mesocolon, and the inferior mesenteric vein for the sigmoid and descending mesocolon. These vessels can be seen routinely on CT scans of the abdomen and pelvis, and knowledge of the anatomy of the mesocolon can help the radiologist understand and identify the pathways for spread of diseases of the colon and pancreas. Recognition of the anatomy of the mesocolon is also helpful in the identification of the pattern of recurrent disease after treatment.