Department of Radiology, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan II Road, Guangzhou, 510080, People's Republic of China.
Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-Sen University, 58 Zhongshan II Road, Guangzhou, 510080, People's Republic of China.
Abdom Radiol (NY). 2021 Mar;46(3):936-947. doi: 10.1007/s00261-020-02765-3. Epub 2020 Sep 22.
To determine the utility of diffusion kurtosis imaging (DKI) for assessing bowel fibrosis and to establish a new magnetic resonance imaging (MRI)-based classification based on DKI and conventional MRI parameters for characterizing intestinal strictures in Crohn's disease (CD) using the histological evaluation of resected intestine samples as the reference standard.
Thirty-one patients with CD undergoing preoperative conventional MRI and diffusion-weighted imaging (DWI) (b values = 0-2000 s/mm) were consecutively enrolled. We classified the mural T2-weighted signal intensity and arterial-phase enhancement patterns on conventional MRI. We also measured DWI-derived apparent diffusion coefficients (ADCs) and DKI-derived apparent diffusion for non-Gaussian distribution (D) and apparent diffusional kurtosis (K). A new MRI-based classification was established to characterize intestinal strictures in CD. Its performance was validated in nine additional patients with CD.
Histological inflammation grades were significantly correlated to T2-weighted signal intensity (r = 0.477; P < 0.001) and ADC (r = - 0.226; P = 0.044). Histological fibrosis grades were moderately correlated to K (r = 0.604, P < 0.001); they were also correlated to D (r = - 0.491; P < 0.001) and ADC (r = - 0.270; P = 0.015). T2-weighted signal intensity could differentiate between no-to-mild and moderate-to-severe bowel inflammation (sensitivity, 0.970; specificity, 0.479). K could differentiate between no-to-mild and moderate-to-severe bowel fibrosis (sensitivity, 0.959; specificity, 0.781). The agreement between the new MRI-based classification and the histological classification was moderate in the test (κ = 0.507; P < 0.001) and validation (κ = 0.530; P < 0.001) sets.
DKI can be used to assess bowel fibrosis. The new MRI-based classification can help to distinguish between fibrotic and inflammatory intestinal strictures in patients with CD.
确定扩散峰度成像（DKI）在评估肠纤维化中的效用，并建立一种新的基于磁共振成像（MRI）的分类方法，该方法基于 DKI 和常规 MRI 参数，以组织学评估为参考标准，对克罗恩病（CD）的肠狭窄进行特征描述。
连续纳入 31 例接受术前常规 MRI 和弥散加权成像（DWI）（b 值=0-2000 s/mm）的 CD 患者。我们对常规 MRI 上的壁 T2 加权信号强度和动脉期增强模式进行分类。我们还测量了 DWI 衍生的表观扩散系数（ADC）和 DKI 衍生的非高斯分布的表观扩散（D）和表观扩散峰度（K）。建立了一种新的基于 MRI 的分类方法，用于对 CD 患者的肠狭窄进行特征描述。在另外 9 例 CD 患者中验证了该分类方法的性能。
组织学炎症程度与 T2 加权信号强度显著相关（r=0.477；P<0.001）和 ADC（r=-0.226；P=0.044）。组织学纤维化程度与 K 中度相关（r=0.604，P<0.001）；与 D（r=-0.491；P<0.001）和 ADC（r=-0.270；P=0.015）也相关。T2 加权信号强度可区分无至轻度和中至重度肠炎症（敏感性为 0.970，特异性为 0.479）。K 可区分无至轻度和中至重度肠纤维化（敏感性为 0.959，特异性为 0.781）。在测试集（κ=0.507；P<0.001）和验证集（κ=0.530；P<0.001）中，新的基于 MRI 的分类与组织学分类之间的一致性为中度。
DKI 可用于评估肠纤维化。新的基于 MRI 的分类方法有助于区分 CD 患者的纤维化和炎症性肠狭窄。
