Usefulness of CT in Assessing Disease Activity of Crohn's Disease

Lee, Seung Soo; Ha, Hyun Kwon; Kim, Ah Young; Kim, Tae Kyoung; Kim, Pyo Nyun; Lee, Moon Gyu

Abstract

PURPOSE
The purpose of this study is to determine the CT features indicating active disease as well as to evaluate the usefulness of CT in assessing disease activity in patients with Crohn's disease.
MATERIALS AND METHODS
Thirty-six patients with Crohn's disease underwent a total of 50 abdominal CT scans. To characterize clinical disease activity, the Crohn's disease activity index (CDAI) was calculated using clinical and laboratory patient data, and C-reactive protein (CRP), levels were also measured. Without knowledge of clinical disease activity, computed tomograms were evaluated in terms of site, target sign, degree of bowel wall enhancement, length, bowel wall thickness, extraluminal hypervascularity, ascites, lymphadenopathy, fibrofatty proliferation, and degree of pericolic or perienteric infiltration. Each finding was compared with the clinical parameters of disease activity.
RESULTS
Both CDAI and CRP were significantly higher in patients with hypervascularity (p=0.005 and 0.028, respectively), long length of involved bowel (p=0.001, 0.001), moderate to severe pericolic or perienteric infiltration (p=0.009, 0.003), or ascites (p=0.001, 0.008). Only CRP was significantly higher in those with heterogeneous bowel wall enhancement (p=0.001), marked bowel wall enhancement (p=0.042), target sign (p=0.031), or severe bowel wall thickening (r=0.410, p=0.003). For other CT findings such as the location, lymphadenopathy, and fibrofatty proliferation, there were no statistically significant differences in CDAI or CRP levels.
CONCLUSION
A number of CT findings varied according to clinical disease activity. These findings are, therefore, useful for evaluating disease activity in patients with Crohn's disease.