【摘要】 目的：探讨体素内不相干运动扩散加权成像（IVIM-DWI）的定量参数在肛瘘活动性评估中的价值。方法：收集75例肛瘘患者的术前MRI图像及临床资料，获取IVIM-DWI序列（b=0、50、100、150、200、300、600、1 000、1 500、2 000 s/mm²）的定量参数，包括：真实扩散系数（D）、假扩散系数（D*）、灌注分数（f）。以肛周疾病活动指数（PDAI）为诊断标准将上述患者分为活动性组（n=51）和非活动性组（n=24）。比较两组患者IVIM-DWI定量参数的差异，并采用受试者工作特征曲线（ROC）计算上述定量参数的诊断效能。结果：活动组和非活动组的D值分别为（0.27±0.20）×10^-3 mm²/s 和（0.52±0.18）×10^-3 mm²/s，差异有统计学意义（P=0.000）;D*值分别为0.10（0.08,0.15）×10^-2mm²/s和0.10（0.08,0.14）×10^-2 mm²/s，差异无统计学意义（P=0.730）;f值分别为0.29±0.07和0.26±0.07，差异无统计学意义（P=0.710）。ROC曲线分析显示D值预测肛瘘活动性的曲线下面积（AUC）为0.900，敏感性和特异性分别为86.3%、79.2%，最佳诊断阈值为0.37×10^-3mm²/s。结论：IVIM-DWI定量参数的D值有助于术前无创性地评价肛瘘的活动性。更多还原

【Abstract】 Objective:To investigate the value of quantitative parameters of intravoxel incoherence motion diffusion weighted imaging （IVIM-DWI） in noninvasive preoperative prediction of anal fistula activity.Methods:Preoperative MRI images and clinical data of 75 patients with anal fistula were collected,quantitative parameters of IVIM-DWI sequence（b=0,50,100,150,200,300,600,1 000,1 500,2 000 s/mm²） were obtained.It includes diffusion coefficient （D）,pseudo-diffusion coefficient（D*）and perfusion fraction （f）.According to perianal disease activity index （PDAI）,the patients were divided into active group and inactive group.The difference of IVIM-DWI quantitative parameters between the two groups were compared,and the diagnostic efficacy of the above quantitative parameters was calculated by receiver operating characteristic curve （ROC）.Results:The D values of active group and inactive group were （0.27±0.20）×10^-3mm²/s and （0.52±0.18）×10^-3mm²/s respectively,and the difference was statistically significant（P=0.000）.The D*values were 0.10（0.08,0.15）×10^-2mm²/s and 0.10（0.08,0.14）×10^-2mm²/s respectively,with no statistical significance（P=0.730）.The f values were 0.29±0.07 and 0.26±0.07 respectively,with no statistical significance（P=0.710）.ROC curve analysis showed that the area under the curve（AUC） of D value in predicting anal fistula activity was 0.900,the sensitivity and specificity were 86.3% and 79.2% respectively,and the optimal diagnostic threshold was 0.37×10^-3mm²/s.Conclusion:The D value of IVIM-DWI is helpful to noninvasively predict the activity of anal fistulas before operation.更多还原