Diagnostic value of magnetized transfer imaging and diffusion-weighted imaging in the evaluation of bowel wall in Crohn disease / 中华放射学杂志

ABSTRACT

Objective To explore the diagnostic value of magnetization transfer imaging (MTI) and DWI for detecting intestinal wall property of crohn's disease (CD). Methods Forty four patients with CD were prospectively enrolled in the study, and MR enterography (MRE), MTI and DWI were performed. According to MRE findings, patients were divided into three subgroupsacute inflammatory group, chronic fibrotic group and combined inflammatory with fibrotic group. Intestinal wall T2WI signal, magnetization transmisson rate (MTR) and ADC value were measured on MRE, MRI and DWI imagings, respectively. The differences of MTR and ADC among the three groups were analyzed by one-way ANOVA;the differences of T2WI scores were analysed by Kruskal Wallis;the differences of MTR and ADC values between normal and pathological intestinal wall were analyzed by paired t test;ROC curve were used to evaluate the CD fibrosis and inflammation diagnostic efficiency of MTI ana DWI based on MRE signs. Results Among the 44 cases, 11 cases were in the acute inflammatory group, 18 cases were in the chronic fibrotic group and other 15 cases were in the combination group. The T2WI score, MTR and ADC among the three groups showed significant differences (all P<0.01).The mean MTR and ADC of pathological intestinal wall of the 44 cases were (40.77±6.05)%and (1.04±0.18)× 10-3mm2/s, and the adjacent normal bowel were (21.75±4.17)%and (1.97 ± 0.23) × 10- 3mm2/s, respectively. Moreover, the difference of the above values showed significant differences (t=19.12,-21.80 respectively, all P<0.01). There was a negative correlation between MTR and T2WI score (r=-0.71,P<0.01). While ADC value was positively correlated with T2WI score (r=0.80, P<0.01). Using ROC curve analysis to differentiate the CD fibrosis from acute inflammation, the area under the curve (AUC) of MTR and ADC were 0.97 and 0.96 ,respectively. Conclusions Both MTI and DWI can be used to assess the properties of intestinal wall, which has the same diagnostic efficacy to identify the acute inflammation and fibrosis.