磁共振扩散加权成像定量评估克罗恩病活动性的临床应用价值

The clinical application value of DWI in quantitative evaluation of Crohn′s disease lesions

目的探讨磁共振扩散加权成像(diffusion weighted imaging,DWI)定量评估肠道克罗恩病(Crohn′s disease,CD)病变的活动性的价值。材料与方法回顾性分析了51例确诊为CD的患者,患者均在2周时间内进行磁共振小肠成像(magnetic resonance enterography,MRE)、DWI及小肠镜检查。根据CD简化内镜活动性评分(simplified endoscopic activity score for Crohn′s disease,SES-CD)将病变肠段分为缓解组(0~2)、轻微活动组(3~6)及中重度活动组(>6)。观察MRE及DWI表现,计算磁共振活动指数(magnetic resonance index of activity,MaRIA)及测量表观扩散系数(apparent diffusion coefficient,ADC)。采用Kruskal-Wallis秩和检验比较不同活动组间MaRIA及ADC值的差异性,采用ROC曲线分析MaRIA及ADC值区分不同活动期病变的诊断效能,MaRIA及ADC值与SES-CD的相关性采用Spearman相关分析。结果共127个肠段纳入研究,缓解组15段,轻微活动组45段,中重度活动组67段,SES-CD评分为1.0~11.0。不同组间MaRIA及ADC值差异均有统计学意义(P均小于0.01)。MaRIA及ADC值与SES-CD的相关性分别为0.793(P<0.01)和-0.742(P<0.01)。ROC曲线分析发现,当MaRIA为9.1,ADC值为-1.585×10-3 mm2/s时,区分缓解组与活动组的曲线下面积最大分别为0.962(P<0.01)及0.957(P<0.01);当MaRIA为11.1,ADC值为-1.345×10-3 mm2/s时,区分缓解-轻微活动组与中重活动组的曲线下面积最大分别为0.942(P<0.01)及0.920(P<0.01)。结论DWI可定量准确区分CD不同活动期病灶。

Objective:To explore the value of magnetic resonance diffusion weighted imaging(DWI)to quantitatively assess the activity of intestinal Crohn's disease(CD)lesions.Materials and Methods:A total of 51 patients diagnosed with CD were retrospectively analyzed,all of those were underwent magnetic resonance enterography(MRE),DWI and enteroscopy within 2 weeks.The lesions of bowel segments were graded as inactive(0-2),mild(3-6),and moderate-severe group(>6)based on simplified endoscopic activity score for Crohn′s disease(SES-CD).To observe the performance of MRE and DWI,and calculate the magnetic resonance index of activity(MaRIA)and the apparent diffusion coefficient(ADC)value of the lesions.The Kruskal-Wallis rank sum test was applied to compare the differences in MaRIA and ADC values among different activity groups,and the receiver operating characteristic(ROC)curve was used to analyze the diagnostic efficiency of MaRIA and ADC values to distinguish different active lesions.Spearman analysis was used to evaluate the correlation between SES-CD and MaRIA,ADC values.Results:A total of 127 intestinal segments were included in the study.There were 15 inactive,45 mild,and 67 moderate-severe.The SES-CD score ranged from 1.0 to 11.0.There were significant differences in MaRIA and ADC values among different groups(P<0.01).The correlations between SES-CD and MaRIA,ADC values were 0.793(P<0.01)and-0.742(P<0.01),respectively.ROC curve analysis found that when the MaRIA was the threshold at 9.1 and the ADC value was the threshold at-1.585×10-3 mm2/s,the maximum of area under the curves(AUCs)to distinguish the inactive from the active were 0.962(P<0.01)and 0.957(P<0.01),respectively.When the MaRIA was the threshold at 11.1 and the ADC value was the threshold at-1.345×10-3 mm2/s,the maximum of AUCs to distinguish the inactive-mild from the moderate-severe were 0.942(P<0.01)and 0.920(P<0.01),respectively.Conclusions:DWI can quantitatively and accurately distinguish the lesions in different active stages of CD.