肝囊型包虫病与单纯性肝囊肿患者肝脏MRI表现分析

Application of apparent diffusion coefficient by diffusion weighted imaging of MR in the differentiate diagnosis of patients with hepatic cystic echinococcosis and simple hepatic cyst

目的 探讨磁共振扩散加权成像(MR DWI)用于鉴别诊断肝囊型包虫病与单纯性肝囊肿的价值。方法 2019年7月~2022年7月我院收治的肝囊型包虫病42例和单纯性肝囊肿34例,均接受MR DWI检测病灶和肝脏表观扩散系数(ADC)。取b值=500 s/mm^(2)和1000 s/mm^(2)时病灶和肝脏ADC值。应用受试者工作特征曲线(ROC)分析ADC值诊断肝囊型包虫病的效能,采用Kappa分析不同b值下病灶ADC值联合诊断肝囊型包虫病与临床诊断结果的一致性。结果 当b值为500 s/mm^(2)时,肝包虫病病灶ADC为(3.1±0.7),当b值为1000 s/mm^(2)时,肝包虫病病灶ADC为(2.4±0.6),显著低于肝囊肿【分别为(3.6±0.9)和(3.2±0.9),P<0.05】;经ROC分析发现,当b值=500 s/mm^(2)时,病灶ADC≤3.235为诊断肝囊型包虫病的最佳截断点,其曲线下面积(AUC)为0.743,95%可信区间(CI)为0.631~0.855,诊断的敏感度为0.706,特异性为0.690(P<0.05),当b值=1000 s/mm^(2)时,病灶ADC≤2.650为诊断肝囊型包虫病的最佳截断点,其AUC为0.857,95%CI为0.771~0.944,敏感度为0.824,特异性为0.762(P<0.05);以达到两种b值下病灶ADC值诊断的截断点为诊断肝包虫病的依据,经一致性分析发现,两种ADC值联合诊断肝囊型包虫病的敏感度为0.929,特异性为0.971,准确率为0.947,阳性预测值为0.975,阴性预测值为0.917,且一致性较高(Kappa=0.894)。结论 相对于单纯性肝囊肿,肝囊型包虫病病灶ADC值显著降低,应用MR DWI检测ADC有助于简易地诊断肝包虫病。

Objective The aim of this study was to investigate the diagnostic efficacy of apparent diffusion coefficient(ADC)by diffusion-weighted imaging(DWI)of magnetic resonance(MR)in patients with hepatic cystic echinococcosis(HCE)and simple hepatic cyst(SHC).Methods Forty-two patients with HCE and 34 patients with SHC were encountered in our hospital between July 2019 and July 2022,and all underwent MR DWI scan.The ADCs of lesions and livers were obtained when the b were at 500 s/mm^(2) and 1000 s/mm^(2).The diagnostic performance of ADC was analyzed by receiver operating characteristic curve(ROC).Finally,the ADC of MR DWI in the diagnosis of HCE was determined by Kappa consistency analysis.Results When the b equal to 500 s/mm^(2),the focal ADC of patients with HCE was(3.1±0.7),and when the b equal to 1000 s/mm^(2),the focal ADC was(2.4±0.6),both much lower than[(3.6±0.9)and(3.2±0.9),respectively,P<0.05]in patients with SHC;the ROC analysis showed that when the b=500 s/mm^(2),the optimal cut-off-value of ADC was set as it less than 3.235,with the AUC of 0.743(95%CI:0.631-0.855)in diagnosis of HCE,the sensitivity(Se)of 0.706 and the specificity(Sp)of 0.690(P<0.05);when the b=1000 s/mm^(2),the focal ADC≤2.650 was set as the diagnosis of patients with HCE,with the AUC of 0.857(95%CI:0.771-0.944),the Se of 0.824,and the Sp of 0.762(P<0.05);the diagnosis of HCE was made when any of the cut-off-value of ADC met the criteria at any b,the consistency analysis confirmed that the diagnostic Se was 0.929,the Sp was 0.971,the accuracy was 0.947,the positive predictive value was 0.975,and the negative predictive value was 0.917(Kappa=0.894).Conclusion The ADC at b=500 s/mm^(2) or b=1000 s/mm^(2) in lesions of HCE significantly decreases as compared with SHC,and the focal ADC could be applied for the differential diagnosis of the two lesions.We recommend each hospital build up its own cut-off-value of ADC for clinical diagnosis.