磁共振常规序列联合DWI序列用于肛瘘术前诊断准确性分析

Accuracy of Routine Magnetic Resonance Imaging Sequence Combined with DWI Sequence in the Preoperative Diagnosis of Anal Fistula

目的 探讨磁共振(MRI)常规序列联合弥散加权成像(DWI)序列用于肛瘘术前诊断准确性分析。方法 选取本院2020年5月到2022年8月肛瘘患者78例,所有患者均接受MRI常规及DWI序列扫描,对比MRI-DWI、常规序列扫描对外口、内口、主瘘管、分支瘘管、脓腔检出率及肛瘘Parks分型准确率,通过受试者工作曲线(ROC)评估表观扩散系数(ADC值)对病灶活动度的评估价值。结果 手术病理证实的78例肛瘘患者中,分别检出外口192个、内口88个、主瘘管78个、分支瘘管156个、脓腔60个,MRI-DWI对外口、内口、主瘘管、分支瘘管、脓腔的检出率分别为86.98%、89.77%、 87.18%、80.13%、81.67%高于单纯MRI常规序到78.13%、73.86%、71.79%、67.31%、63.33%(P<0.05);78例肛瘘患者parks分型包括Ⅰ型30、Ⅱ型25例、Ⅲ型14例、Ⅳ型9例;MRI-DWI对肛瘘parks分型Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型的诊断与病理结果的一致性Kappa值分别为0.833、0.769、0.788、0.820,均>0.75,二者一致性均较好,MRI-DWI对肛瘘prks分型Ⅰ型、Ⅱ型、Ⅲ型、Ⅳ型诊断准确率分别为92.31%、87.74%、93.59%、96.15%均高于单纯MRI常规序列诊断准确率7.654%、74.36%、79.49%、88.46%,总体准确率为85.90%高于MRI常规序列58.97%(P<0.05);78例患者肛瘘病灶活动度包括活动期29例,缓解期49例,缓解期患者ADC值高于活动期患者(P<0.05);ROC曲线分析显示ADC值评价肛瘘病变活动性曲线下面积0.908,灵敏度82.80%,特异度85.70%。结论 MRI-DWI诊断肛瘘有较高应用价值,Parks分型准确,对疾病活动度的评估价值较高,可准确检测出肛瘘内口、外口、主瘘管、分支瘘管和脓腔等。

Objective To explore the accuracy of routine magnetic resonance imaging(MRI)sequence combined with diffusion-weighted imaging(DWI)sequence in the preoperative diagnosis of anal fistula.Methods The patients with anal fistula in the hospital were enrolled between May 2020 to August 2022.All underwent routine MRI and DWI sequence scans.The detection rates of external orifice,internal orifice,main fistula,branch fistula and abscess cavity,and accuracy rates of parks classifications by MMRI-DWI and routine sequence scan were compared.The evaluation value of apparent diffusion coefficient(ADC)for lesion activity was assessed by receiver operating characteristic(ROC)curves.ResultsIn the 78 patients with anal fistula confirmed by surgical pathology,there were 192 external orifice,88 internal orifice,78 main fistula,156 branch fistula and 60 abscess cavity.The detection rates of external orifice,internal orifice,main fistula,branch fistula and abscess cavity by MRI-DWI were 86.98%,89.77%,87.18%,80.13%and 81.67%,higher than those of routine MRI sequence(78.13%,73.86%,71.79%,67.31%,63.33%,P<0.05).In the 78 patients with different anal fistula parks classifications,there were 30 cases with typeⅠ,25 cases with typeⅡ,14 cases with typeⅢand 9 cases with typeⅣ.Consistency Kappa values between MRI-DWI and pathological diagnosis for different parks classifications(typeⅠ,typeⅡ,typeⅢ,typeⅣ)were 0.833,0.769,0.788 and 0.820,with good consistency.The diagnostic accuracy rates of typeⅠ,typeⅡ,typeⅢand typeⅣanal fistula by MRI-DWI were 92.31%,89.74%,93.59%and 96.15%,higher than those by routine MRI sequence(75.64%,59.26%,45.00%,50.00%),and overall accuracy rate was higher than that by routine MRI sequence(85.90%vs 58.97%,P<0.05).In the 78 patients with anal fistula,there were 29 cases in active stage and 49 cases in remission stage.ADC in remission stage was greater than that in active stage(P<0.05).ROC curves analysis showed that area under the curve(AUC),sensitivity and specificity of ADC for evaluating anal fistula lesion activity were 0.908,82.80%and 85.70%,respectively.ConclusionMRI-DWI has high diagnostic value for anal fistula,accurate parks classifications and high evaluation value for disease activity.It can accurately detect the internal orifice,external orifice,main fistula,branch fistula and abscess cavity.