Diagnostic Value Of Contrast-enhanced Ultrasonography In Cervical Lymph Node Metastasis Of Differentiated Thyroid Carcinoma

[Objective]This study aimed to prospectively evaluate the accuracy of contrast-enhanced ultrasonography(CEUS)examination in diagnosing cervical lymph node metastasis in differentiated thyroid cancer(DTC).[Materials and Methods]Between January 2018 to September 2018,74 patients underwent CEUS examination,and only 62 patients were finally treated with surgery.A total of 102 cervical lymph nodes(55 metastatic lymph nodes and 47 benign lymph nodes)were recruited for the study.They were evaluated by ultrasonography(US)examination and CEUS examination before surgery.The puncture positioning of lymph nodes assessed using CEUS examination on the day of surgery ensured the accuracy of pathological results.During the operation,the localized lymph nodes were removed separately and sent to the pathology department for diagnosis.[Results]For 55 cases of metastatic lymph nodes,24 cases(43.64%)were considered metastatic using US examination,and 4 cases(7.27%)were considered benign;the nature of lymph nodes could not be judged in 27 cases(49.09%).CEUS examination was prompted in 49 cases(89.09%)with metastasis,2 cases(3.64%)with uncertain nature,and 4 cases(7.27%)with benign nature.For 47 cases of benign lymph nodes,3 cases(6.38%)were considered to have metastasis using US examination,and 15 cases(31.92%)were considered to have benign lymph nodes;the nature of lymph nodes could not be judged in 29 cases(61.70%).Four cases(8.51%)were considered metastatic,2 cases(4.26%)were uncertain,and 41 cases(87.23%)were considered benign in CEUS examination.The main manifestations of US examination of metastatic lymph nodes were long axis/short axis ratio more than 1.5(34 cases,61.82%),disappearance of hilar structure(47 cases,85.45%),medium echo(28 cases,50.91%),and mixed blood flow(23 cases,41.82%).In the benign lymph nodes,long axis/short axis ratio more than 1.5 only in 7 cases(14.89%).The disappearance of hilar structure in 26 cases(55.32%),medium echo in 14 cases(29.79%)and mixed blood flow in 12 cases(25.53%).CEUS exasented centripetal enhancement,while 37 cases(78.72%)of benign lymph nodes shomination of lymph nodes revealed that 29 cases(52.73%)of metastatic lymph nodes prewed centripetal enhancement.Filling defects were found in 7(12.73%)of metastatic lymph nodes,while only 1(2.13%)of benign lymph nodes.For 102 lymph nodes,the total diagnostic accuracy of CEUS examination was 88.24%,which was better than that of US examination(38.24%).[Conclusions]1.The main manifestations of metastatic lymph nodes in US examination were long axis/short axis ratio more than 1.5,disappearance of hilar structure,medium echo,and mixed blood flow.2.CEUS examination of metastatic lymph nodes mostly showed centripetal or mass enhancement,and filling defects may occur in some lymph nodes.3.CEUS examination is a promising diagnostic tool superior to conventional ultrasonography in diagnosing metastatic lymph nodes of DTC.