Colon and rectum inflammatory and infectious diseases

Abstract

Inflammatory and infectious colitides are a common cause of acute abdominal pain. The colon responds to injury from inflammation or infection in a limited number of ways. The appearance, severity, distribution, and progression of imaging findings can be used to limit the differential diagnosis and often can help to make a specific diagnosis. Determining whether the colonic involvement is asymmetric or symmetric, diffuse versus focal, and/or involves the rectum can help narrow the differential diagnosis. The presence of additional bowel involvement beyond the colon and other extracolonic findings may help to further narrow the differential diagnosis of colonic inflammation. Benign disease, predominantly consisting of the inflammatory and infectious disease processes typically demonstrate circumferential colonic wall thickening on CT. The wall can appear as homogeneous soft tissue density or demonstrate stratification with either a double halo or target sign. CT can also detect the complications of inflammatory and infectious disease processes and assist with management. This chapter will review unique radiologic features, with an emphasis on CT and MRI, of inflammatory and infectious disease of the colon.