Computed Tomography Enterography for Evaluation of Inflammatory Bowel Disease

Abstract

Computed tomography enterography (CTE) has become a main modality for the evaluation of inflammatory bowel disease (IBD). It simultaneously offers visualization of the small bowel and extraintestinal status, which is helpful for diagnosing IBD. Crohn disease has long segmental enhancing wall thickening related with the eccentric longitudinal distribution. In addition, mural stratification, fibrofatty proliferation, positive comb sign by increased mesenteric vascularity and internal/perianal fistula are characteristics of Crohn disease and can be identified on CTE. Short segmental inflammatory wall thickening and the central low attenuated lymph nodes are favorable CT finding of intestinal tuberculosis. A geographic, relatively large, and deep penetrating ulcer with bowel wall thickening and mural hyperenhancement in ileocecal area are characteristics of intestinal Behcet disease. Each of CTE findings for the IBDs is helpful for differential diagnosis. The main disadvantage of this technique is the requisite radiation exposure of patients, particularly in young patients. However, recent development of advanced CT techniques is promising for radiation dose reduction without compromising diagnostic image quality.

Lipomatosis of the terminal ileum and ileocaecal valve: multidetector CT findings

“…We need to keep in mind that Crohn's disease has major findings such as intestinal wall thickening, mural hyperenhancement and increased attenuation of mesenteric fat in active disease. Fibrotic strictures, fistule and abscess can develop in the chronic phase 11. Our patient's physical and laboratory findings were not compatible with Crohn's disease.…”

The Role of the Mesentery in Crohnʼs Disease

“…97 The comb sign resulted from an increased mesenteric vascularity, is an imaging characteristic of CD. 98,99 Higher blood flow, lower resistant index, and small diameter of mesenteric vasculature could lead to the enlargement of the vasa recta. The cumulative clinical evidence suggests that the function of vasculature is altered in CD.…”

Measuring disease activity in Crohn's disease: what is currently available to the clinician

“…CT enterography requires an adequate luminal distension obtained by means of oral contrast agents (such as polyethylene glycol solutions), and the intravenous administration of contrast medium is essential to assess bowel wall enhancement and mesenteric vessels 52. Typical CT findings of active CD are mural hyperenhancement, bowel wall thickening (>3 mm), mural stratification due to intramural edema, engorged vasa recta (comb sign), and increased attenuation of mesenteric fat.…”