Approach to colon pathologies

This chapter begins with a review of colonic anatomy and embryology followed by a discussion of CT protocols used for evaluating the colon. Differential diagnostic considerations are presented for colonic wall thickening, colonic masses, and colonic dilatation. Causes of colonic wall thickening are described including inflammatory bowel disease, infectious colitis, colopathy secondary of portal hypertension, typhlitis, diverticulitis, ischemic colitis, radiation colitis, graft versus host disease, and trauma with key imaging features provided for each entity. Imaging findings of colonic masses including adenocarcinoma, lymphoma, gastrointestinal stromal tumor, and lipoma are reviewed. Causes of colonic dilatation including obstruction, ileus, volvulus, Hirschsprung’s disease, and toxic megacolon are discussed along with key imaging features for each entity. The chapter concludes with a discussion of colonic vascular abnormalities including angiodysplasia and hemangioma.