Department of Radiology, First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, P.R. China.
Department of Biomedical Engineering, Cancer Biology and Radiology, Wake Forest School of Medicine, Winston-Salam, North Carolina, USA.
J Magn Reson Imaging. 2018 Mar;47(3):702-709. doi: 10.1002/jmri.25768. Epub 2017 Jun 3.
To assess the efficacy of diffusion kurtosis imaging (DKI) and to compare DKI-derived parameters with that of conventional diffusion-weighted imaging (DWI) for grading the inflammatory activity of Crohn's disease (CD).
In all, 38 patients with CD underwent 3T magnetic resonance enterography (MRE) with DKI (b values of 0-2000 s/mm ). The inflammatory activity of the bowel segments was graded by magnetic resonance index of activity (MaRIA) as inactive (<7), mild (≥7 and <11), or moderate-severe (≥11). Apparent diffusion for non-Gaussian distribution (D ) and apparent kurtosis coefficient (K ) on DKI as well as apparent diffusion coefficient (ADC) on DWI were compared.
In all, 86 bowel segments including inactive (20), mild (19), and moderate-severe (47) CD were analyzed. The differences in K , D , and ADC among inactive, mild, and moderate-severe CD were significant (all P < 0.05). K (r = 0.862), D (r = -0.755), and ADC (r = -0.713) correlated well with MaRIA in all segments. Stronger correlation with MaRIA in moderate-severe CD was found for K (r = 0.647) than that of D (r = -0.414) and ADC (r = -0.580). Receiver operating characteristic (ROC) curve analysis showed high accuracy of K , D , and ADC for differentiating active from inactive CD (AUC: 0.953 for K , 0.944 for D , 0.907 for ADC) as well as differentiating inactive-mild from moderate-severe CD (AUC: 0.946 for K , 0.887 for D , 0.846 for ADC). The threshold K of 0.731 allowed differentiation of active from inactive CD with 89.4% sensitivity and 95% specificity.
DKI of CD is clinically feasible and might be superior to conventional DWI for grading the inflammatory activity of CD.
2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:702-709.
评估扩散峰度成像（DKI）的疗效，并比较 DKI 衍生参数与常规扩散加权成像（DWI）在克罗恩病（CD）炎症活动分级中的应用。
本研究共纳入 38 例 CD 患者，均行 3T 磁共振肠造影术（MRE）并进行 DKI（b 值范围为 0-2000 s/mm ）检查。采用磁共振活动指数（MaRIA）对肠段的炎症活动进行分级，将其分为无活动（<7）、轻度（≥7 且 <11）和中重度（≥11）。比较 DKI 上的非高斯分布表观扩散系数（D ）和表观峰度系数（K ）以及 DWI 上的表观扩散系数（ADC）。
共分析了 86 个肠段，包括无活动（20 个）、轻度（19 个）和中重度（47 个）CD。无活动、轻度和中重度 CD 之间的 K 、D 和 ADC 差异均有统计学意义（均 P < 0.05）。所有肠段中 K （r = 0.862）、D （r = -0.755）和 ADC （r = -0.713）与 MaRIA 相关性良好。与 D （r = -0.414）和 ADC （r = -0.580）相比，K 在中重度 CD 中与 MaRIA 的相关性更强（r = 0.647）。ROC 曲线分析显示，K 、D 和 ADC 对区分活动与无活动 CD 的准确率较高（AUC：K 为 0.953，D 为 0.944，ADC 为 0.907），区分无活动-轻度与中重度 CD 的准确率也较高（AUC：K 为 0.946，D 为 0.887，ADC 为 0.846）。当 K 的阈值为 0.731 时，可将活动与无活动 CD 区分开来，其灵敏度为 89.4%，特异度为 95%。
CD 的 DKI 具有临床可行性，且可能优于常规 DWI 用于 CD 炎症活动分级。
2 技术疗效：阶段 2 J. Magn. Reson. Imaging 2018;47:702-709.
