Evaluation Of Diagnostic Efficiency Of Metastatic Lymph Nodes Based On SWE Parameters

Objective:The purpose of this study was to evaluate the diagnostic efficacy of shear wave elastography(SWE)index including the maximum Young’s modulus(Edoppler)at the color flow imaging(CDFI)in the diagnosis of metastatic lymph nodes,and to analyze the value of different shear wave elastography index(EI)values in the differential diagnosis of metastatic lymph nodes and tuberculous lymph nodes.Methods: From August 1,2019 to December 31,2020,106 patients(153 lymph nodes)with suspicious lymph nodes were detected by ultrasound(US)in the Department of ultrasound medicine in Affiliated Hospital of Yan’an University.Two dimensional ultrasound(2D-US)and color Doppler flow imaging(CDFI)were performed on them was used to record the long diameter,short diameter,ratio of long diameter to short diameter of lymph nodes,blood flow type of lymph nodes,specific location of target lymph nodes and boundary of cortex and medulla.The maximum Young’s modulus(Emax),the average young’s modulus(Emean),the minimum Young’s modulus(Emin),the ratio of the maximum Young’s modulus of lymph nodes to the maximum Young’s modulus of muscle tissue in the same plane(ER),and the maximum Young’s modulus at the color Doppler flow imaging were measured by SWE technique.The pathological results were obtained after puncture biopsy or surgery to determine the nature of lymph nodes,Receiver operating characteristic(ROC)curve was drawn and the diagnostic efficiency of each parameter was judged.Results: There were significant differences in Emax,Emean,Emin,ER and Edoppler between benign and metastatic lymph nodes.Draw the ROC curve and calculate the area under the curve(AUC).The AUC of Emin was less than 0.5(0.396),which had low authenticity and no application value.The best cut-off value is selected according to the maximum Youden index,Emax,Emean,ER and Edoppler were 48.6kpa,23.5kpa,2.15 and 45.2kpa respectively.There were no significant differences in the five parameters between different primary cancers and different pathological types.There was no significant difference in Emin between metastatic lymph nodes and lymph node tuberculosis(P > 0.05),but there was significant difference in the other four EI values.AUC(95% confidence interval)of Emax,Emean,ER and Edoppler were 0.815(0.711-0.918),0.700(0.582-0.818),0.715(0.595-0.836)and 0.811(0.698-0.924),respectively.Conclusion:1.There was no difference in the accuracy of Emax,Emean,ER and Edoppler in differentiating benign and metastatic lymph nodes.Edoppler had the highest authenticity and could be the first choice for the diagnosis of metastatic lymph nodes.2.Emin can not differentiate tuberculosis from metastatic lymph nodes,and the accuracy of differentiating benign and metastatic lymph nodes is too low.3.EI can not predict the pathological type and primary lesion type of metastatic lymph nodes.