Quantitative study on grading activity of Crohn disease with CT enterography

Abstract

Objective To explore the feasibility and the value of CT enterography (CTE) in the quantitative evaluation of Crohn's disease (CD). Methods Retrospectively analyzed 49 patients diagnosed as CD by clinical, enteroscopy, pathology, and imaging from April 2016 to June 2017 in Zhongnan Hospital of Wuhan University. All patients underwent routine enteroscopy and standardized CTE. The interval between the two examinations was less than 2 weeks. Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels were measured at intervals. The ESR ranged from 2.0 to 97.0 mm/1 h, with an average of (30.6±26.5) mm/1 h, CRP from 0.3 to 143.3 mg/L, and a median of 27.7 mg/L. CD patients were classified into inactive, mild and moderate-severe according to Crohn's disease simplified endoscopic activity score(SES-CD) after enteroscopy. CTE evaluated the site of lesion, the thickness and enhanced patterns of the most severe lesions of the bowel wall, mural enhanced CT value in the portal vein phase, ΔCT value, stenosis, perienteric inflammation, mesenteric hypervascularity (comb sign), enlarged lymph nodes, abdominal abscesses, fistulas, etc. The Chi-square test was used to compare the differences of enhanced patterns among different groups. ANOVA (Analysis of Variance) was used to compare the differences in bowel wall thickness, plain CT values, mural enhanced CT value in the portal vein phase and ΔCT values among different groups. The correlation between CTE parameters and SES-CD or laboratory data was analyzed by Pearson (normal distribution data) or Spearman (skewed distribution data). Results SES-CD ranged from 1 to 15, with an average of 5.1±2.6. Among 49 cases, 13 were inactive, 19 were mild, and 17 were moderate-severe. There were 25 cases of intestinal obstruction or stenosis, including 24 cases in the active group and 1 case in the non-active group, and the difference was statistically significant (χ2=13.3, P 0.05). Bowel wall thickness, mural enhanced CT value in the portal vein phase and ΔCT values were all moderately correlated with SES-CD (r were 0.564, 0.585, 0.533, respectively; P all 0.05). Conclusion The bowel wall thickness, mural enhanced CT value in the portal vein phase and the ΔCT value can be used to accurately assess the activity of CD lesions. Key words: Crohn disease; Tomography,X-ray computed; Simplified endoscopic activity score for Crohn disease