Department of Gastroenterology, University Hospital Estaing of Clermont-Ferrand, Auvergne University, France.
Aliment Pharmacol Ther. 2013 Mar;37(5):537-45. doi: 10.1111/apt.12201. Epub 2013 Jan 7.
Whether diffusion-weighted imaging (DWI)-MRI is of value in detecting and assessing inflammation of ileal Crohn's disease (CD) remains poorly investigated.
To compare DWI-MR enterography (MRE) with conventional MRE in estimating inflammation in small bowel CD, to determine an apparent diffusion coefficient (ADC) threshold to differentiate active from non-active lesions and to assess inter-observer agreement.
Thirty-one CD patients from the Clermont-Ferrand IBD unit with ileal involvement were consecutively and prospectively included between April and June 2011. All patients underwent DWI-MRI to detect the digestive segment with the most severe lesions, which was then used to calculate the ADC. Qualitative and quantitative results were compared with conventional MRE including MaRIA (Magnetic Resonance Index of Activity) score calculation and independent activity predictors (wall thickening, oedema, ulcers). Each examination was interpreted independently by two radiologists blinded for clinical assessment.
Seventeen patients (54.8%) had active CD as defined by the MaRIA score ≥7. DWI hyperintensity was highly correlated with disease activity evaluated using conventional MRE (P = 0.001). Qualitative analysis of DW sequences determined sensitivity, specificity, positive predictive value and negative predictive value as 100%, 92.9%, 94.4% and 100% respectively. Quantitative analysis using a cut-off of 1.6 × 10(-3) mm(2)/s for ADC yielded sensitivity and specificity values of, respectively, 82.4% and 100%. Inter-observer agreement was high with regard to DWI hyperintensity (κ = 0.69, accuracy rate = 85.7%) and ADC (correlation = 0.74, P < 0.001, and concordance = 0.71, P < 0.001).
DWI-MR enterography is a well-tolerated, non-time-consuming and accurate tool for detecting and assessing inflammation in small bowel Crohn's disease.
弥散加权成像（DWI）-MRI 检测和评估回肠克罗恩病（CD）炎症的价值仍未得到充分研究。
比较 DWI-MR 肠造影（MRE）与常规 MRE 估计小肠 CD 炎症的情况，确定区分活动与非活动病变的表观扩散系数（ADC）阈值，并评估观察者间的一致性。
2011 年 4 月至 6 月，连续前瞻性纳入来自克莱蒙费朗 IBD 单位的 31 例回肠受累的 CD 患者。所有患者均接受 DWI-MRI 检查以检测病变最严重的消化道段，然后计算 ADC。定性和定量结果与常规 MRE 进行比较，包括 MaRIA（活动指数）评分计算和独立活动预测因子（壁增厚、水肿、溃疡）。两名放射科医生对每一次检查均进行独立解读，且对临床评估不知情。
17 例患者（54.8%）的 MaRIA 评分≥7，定义为活动期 CD。DWI 高信号与常规 MRE 评估的疾病活动高度相关（P = 0.001）。DW 序列的定性分析确定了敏感性、特异性、阳性预测值和阴性预测值分别为 100%、92.9%、94.4%和 100%。使用 ADC 截断值 1.6×10(-3)mm(2)/s 进行定量分析，获得的敏感性和特异性值分别为 82.4%和 100%。DWI 高信号（κ=0.69，准确率=85.7%）和 ADC（相关性=0.74，P<0.001，一致性=0.71，P<0.001）的观察者间一致性较高。
DWI-MR 肠造影是一种耐受性好、耗时短且准确的工具，可用于检测和评估小肠 CD 的炎症。
