论文部分内容阅读
目的 探讨3.0T磁共振(MRI)扩散加权成像(DWI)序列及其定量参数表观扩散系数(ADC)值在手术前后准确评价肛瘘活动性,以提高手术成功率同时降低术后复发率中的应用价值.方法 回顾性分析49例经手术证实的复杂性肛瘘患者的临床资料,分析患者常规MRI及DWI序列图像特征,通过ADC图测量病灶ADC值,根据临床评价肛周疾病活动性指数(PDAI)将患者分为活动期组(19例)与缓解期组(30例),利用两独立样本t检验将两组的ADC均值进行比较,并绘制受试者工作特征曲线(ROC);同时将ADC评价活动性结果与PDAI指数进行相关性分析.结果 测得ADC均值,缓解期组为(1.252±0.170)×10-3mm2/s,活动期组为(0.925±0.148)×10-3mm2/s,活动期瘘管的ADC均值低于缓解期(P＜0.001).ROC曲线分析显示ADC值评价肛瘘病变活动性的曲线下面积(AUC)为0.94;取曲线中Youden指数最高时的截断ADC值1.101×10-3 mm2/s为鉴别阈值,诊断敏感度为80％,特异度为94.7％ (P ＜0.001).相关性分析,病灶ADC值与PDAI值呈负相关(r=-0.89,P＜0.001).结论 DWI-MRI序列及其定量参数ADC值可较准确地判断病变活动性,应作为手术前后MRI检查肛瘘的常规序列加以开展,有助于帮助临床医生术前制定正确治疗方案以提高手术成功率,更适合于术后长期随访复查中应用.“,”Objective To investigate the application value of DWI-MRI and ADC for evaluating perianal fistula activity.Methods 49 patients with histologically proven complicated perianal fistula were retrospectively assessed in this study,with all patients underwent conventional 3.0T MRI and DWI sequences,and the apparent diffusion coefficient (ADC)value of the lesions were measured on the ADC maps.Lesions were classified into two groups based on the perianal disease activity (PDAI) index:positive inflammation activity (PIA) and negative inflammation activity (NIA).ADCs of both groups were compared using an unpaired t-test,and Receiver Operating Characteristic (ROC) analysis was performed.Meanwhile,the relationships between the ADC value and PDAI were analyzed.Results The mean ADC value (in × 10-3mm2/s) of the PIA group (0.925 ±0.148) was significantly lower (P ＜0.001) than that of the NIA group (1.252 ± 0.170).The area under receiver operating characteristic curve was 0.94,and the optimal cut-off ADC of 1.101 yielded a sensitivity of 80％,a specificity of 94.7％.Conclusion DWI-MRI and ADC value are helpful to evaluate perianal fistula activity with high accuracy,which should be established as one of the routine MR sequences before and after the clinical operations to decrease the recurrence rates.