Study Of Creeping Fat In The Diagnosis And Evaluation Of Crohn’s Disease

Objective:To investigate and analyze the value of creeping fat in the diagnosis of Crohn’s disease and the evaluation of its activity and severityMethods:The spectral CT enterography data from a cohort of 40Crohn’s disease patients and 40 controls from Mars 2014 to Mars 2015 were analyzed retrospectively.The results of ileocolonoscopy,HBI and CRP of all the CD patients were obtained.Terminal ileum,right colon,transverse colon,left colon and rectum were evaluated respectively according to SES-CD.All the bowel segments were classified into three categories,namely endoscopically normal segments,segments with mild lesions and segments with moderate/severe lesions.Mild lesion was defined as absence of ulcers including erosion,erythema,pseodopolypes and edema.Moderate/severe lesion was defined as all kinds of ulcers and stenosis.We then analyzed all the bowel segments of CD patients and controls on spectral CTE images in order to obtain the λHU and NWC of mesenteric adipose tissue of normal segments and segments with lesions.The visceral fat area(VFA),subcutaneous fat area(SFA)and the volume ratios,mesenteric fat index(MFI)were measured and calculated on CT image at the umbilical level.Parameters in spectral CTE mode together with VFA and MFI were used to establish logistic regression and comparisons were made to see which method was better in the diagnosis of Crohn’s disease.ROC curve was used to predict the accuracy of spectral CTE in the evaluation of disease activity and severity.Pearson test was used to make correlations between NWC,λHU and HBI,CRP and SES-CD.Results:λHU and NWC increased progressively with disease severitybut the NWC between controls and endoscopically normal segments group showed no significance.According to the logistic regression model based on the parameters in spectral CTE,λHU and NWC featured good accuracy in predicting disease activity and severity.Compared with the ROC curve of the logistic regression model based on VFA and MFI,λHU and NWC featured higher accuracy(0.975 vs.0.776),sensitivity(92.0% vs.77.5%)and specificity(92.7% vs.67.5%).λ HU and NWC correlated positively with SES-CD.Conclusions: Using spectral CTE to quantitatively analyze the creeping fat in the diagnosis of Crohn’s disease and the evaluation of its activity and severity was superior to the way of using VFA and MFI,and showed values in the clinical application.