The Value Of Magnetic Resonance Enterography And Diffusion-weighted Imaging In Evaluating Crohn’s Disease Activity

Objective To evaluate the activity of Crohn’s disease by the combination of magnetic resonance enterography(MRE)and diffusion-weighted imaging(DWI),Establishing a new quantitative scoring model to evaluate the activity of Crohn’s disease,and then evaluate the efficacy of the model.Materials and Methods Patients diagnosed as Crohn’s disease in a hospital in Jiangsu province from January 2015 to December 2017 were selected into this retrospective analysis.All of them made MRE and DWI examination in the course of the disease.Imaging data were applied to further study.Mural thickness,T2 WI intestinal signal,T2 WI perienteral fat-suppressed signal,contrast enhancement,Mural enhancement pattern,DWI signal,lymph node,and comb sign of terminal ileum were scored qualitatively(0–3).In addition,Clermont score was calculated according to these indexes of the thickness of the intestinal wall at terminal ileum,the ADC value,the edema of the intestinal wall and the ulcer.The terminal ileum were divided into two groups(inactive group and active group)according to the gold standard of simplified endoscopic activity score(SES-CD)criterion.Categorical variables were compared using the χ2 test.To explore the correlation between MRE,DWI image index score and SES-CD,and then to make a magnetic resonance linear regression equation.The sensitivity,specificity,positive predictive value,negative predictive value and ROC curve were applied to judge the value of the linear regression equation of magnetic resonance and the Clermont score.score for evaluating the activity of Crohn’s disease.Results: 75 patients,the terminal ileum was included in the analysis.Mural thickness,T2 WI perienteral fat-suppressed signal,T2 WI intestinal signal,enhancement degree,Mural enhancement pattern,DWI signal,and comb sign were statistically significant between the remission group and the active group(P value.All were <0.05),and there was no statistically significant difference in lymph node size between the two groups(P > 0.05).The scores of 8 images were correlated with SES-CD(P<0.05),and the derived magnetic resonance regression equation =-1.301 + 0.991 × enhancement score + 0.899 × DWI signal score + 0.641 × T2 WI signal score + 0.702 × Mural thickness score.The magnetic resonance linear regression model has a cutoff value of 3.3 and Clermont score cutoff of 9.5,The diagnostic activity is the highest,with AUC of 0.98 and 0.83,respectively.The magnetic resonance linear regression equation has a cut-off value of 5.6 and Clermont score cutoff of 11.2.The most effective diagnosis of moderate-to-severe active lesions is AUC of 0.93 and 0.86,respectively.Conclusion MRE and DWI can effectively evaluate Crohn’s activity.Magnetic resonance linear regression equation can be used to quantitatively evaluate the activity of Crohn’s disease,and the ability of linear regression equation to evaluate the activity of Crohn’s disease is better than Clermont score.