磁化传递成像评估克罗恩病肠瘘发生风险的应用价值

Magnetization Transfer MR Imaging for Predicting Intestinal Fistula in Patients with Crohn Disease

【目的】探讨磁化传递成像(MTI)预测克罗恩病(CD)患者肠瘘发生风险的应用价值。【方法】分析12例CD手术患者的术前MTI资料,在磁化传递率(MTR)图像上测量并计算病变肠壁的标准化MTR(标准化MTR=肠壁MTR/肌肉MTR)。采用MTI图像和手术切除肠道区域对区域定位的方法,切取对应位置的肠壁组织行Masson染色以评估纤维化程度。采用Wilcoxon秩和检验比较有肠瘘和无肠瘘肠壁的标准化MTR,绘制ROC曲线分析标准化MTR预测CD肠瘘发生的效能。【结果】12例患者手术切除15个病变肠段,共获取35个肠壁标本,其中发生肠瘘的肠段有5段共12个标本,无发生肠瘘的肠段有10段共23个标本。有肠瘘的肠壁标准化MTR高于无肠瘘者(P=0.045)。ROC曲线分析显示标准化MTR预测病变肠壁发生肠瘘风险的曲线下面积为0.674(95%置信区间:0.537-0.811);以标准化MTR=0.768为诊断阈值时,诊断可能发生肠瘘的敏感度和特异度分别为93.3%、51.1%。有肠瘘的肠壁的纤维化评分高于无肠瘘者(P=0.012)。肠壁标准化MTR与纤维化评分呈正相关(r=0.708,P<0.001)。【结论】MTI可能有助于预测CD肠瘘的发生风险,可提前为临床制定有效治疗策略提供有价值的信息。

【Objective】To evaluate the feasibility of magnetization transfer(MT)magnetic resonance(MR)imaging for predicting the risk of intestinal fistula in patients with Crohn disease(CD).【Methods】The study prospectively enrolled 12 consecutive patients with CD and abdominal MT imaging were performed before elective surgery.The bowel wall MT ratio normalized to skeletal muscle was calculated;region-by-region correlations with the surgical specimen were performed.Histopathologic evaluation of fibrosis was executed by using Masson trichrome.Wilcoxon rank test,Spearman rank correlation,and receiver operating characteristic curve(ROC)were used for statistical analysis.【Results】Among 15 surgical intestinal segments from 12 patients,5 lesions were found with intestinal fistula and of them 12 bowel specimens were obtained.The other 10 intestinal segments were without complications and 23 bowel specimens were enrolled.The intestinal fistula bowel showed a significant higher(P=0.045)normalized MT ratio.ROC analysis revealed an area under the curve of 0.674(95%CI:0.537-0.811)for differentiating intestinal fistula bowel from the nonfistula one.The sensitivity,specificity was 93.3%and 51.1%with a cut-off value of 76.8%,respectively.For the Masson ones.Additionally,the normalized MT ration was statistical correlated with Masson score(r=0.708,P<0.001).【Conclusion】MT imaging could be a potential method to predict the risk of intestinal fistula in patients with CD.