A Study On The Value Of Young’s Modulus Of “shell” In Differentiating Benign And Malignant Thyroid Nodules Based On Different Thicknesses Of Sound Touch Elastography

Objective:To measure the Yang’s modulus value in different thickness areas around the thyroid nodules by the "shell" tool,quantitatively reflect the hardness information of the peripheral edge of the nodules,and provide a new idea for the differential diagnosis of benign and malignant thyroid nodules.Methods:In this study,203 patients with thyroid nodules were diagnosed by conventional ultrasound in the second affiliated Hospital of Nanchang University from July 2019 to May 2020,a total of 203 nodules.All patients included in the study underwent preoperative sound touch elastography(STE).Using Mindray Resona 7s ultrasound diagnostic instrument and its "shell" analysis tool,drawing the entire edge of the nodule.When "shell" is 1mm,2mm and 3mm,the system automatically calculates the Young’s modulus of the corresponding "shell",that is,maximum elastic modulus(Emax),mean elastic modulusand(Emean),minimum elastic modulus(Emin)and elastic modulus standard deviation(Esd),repeat the above process,measure three times,take the average value and record it.According to the pathological results,thyroid nodules were divided into benign and malignant groups,statistical analysis of the difference of Young’s modulus between the two groups.The receiver operating characteristic(ROC)of the subjects were drawn according to the Young’s modulus values of the corresponding regions around the nodules with different "shell" values(i.e.1mm,2mm and 3mm).The best diagnostic values of Young’s modulus in different extrusive regions around thyroid nodules were determined and to evaluate their diagnostic efficacy in differentiating benign and malignant thyroid nodules.Results:1.203 thyroid nodules in this study,of the 78 patients diagnosed as malignant,diagnosed as benign 125.Malignant nodules include 66 papillary carcinomas,6follicular cancers,5 medullary carcinomas,1 lymphoma.Benign nodules include 78 nodular goiter,24 follicular and eosinophilic adenomas,12 hashimoto’s thyroiditis,6nodular goiter with adenomatous hyperplasia,3 nodular goiter with atypical hyperplasia,2 granulomatous thyroiditis.2.The general data of 203 benign and malignant thyroid nodules were compared:the age,sex and nodule diameter were not statistically significant(P>0.05).3.According to the pathological results,203 thyroid nodules were divided into benign and malignant groups.When "shell" take 1mm,2mm and 3mm,the Emax,Emean and Esd of malignant group were significantly higher than those of benign group,statistically significant(P<0.05).When "shell" takes 1mm,the Emin of malignant group is lower than that of benign group.When " shell" takes 2mm and3 mm,the Emin of malignant group is higher than that of benign group.But whether "shell" take 1mm,2mm or 3mm,no significant difference is found between benign and malignant groups(P>0.05).4.Three different "shell" ROC curves were constructed according to the gold standard.When "shell" take 1 mm,2mm and 3mm,the best cut-off value of Emax are53.25 k Pa,58.76 k Pa,58.47 k Pa,respectively area under the curve(AUC)are 0.892,0.952,0.938;the best cut-off value of Emean are 25.67 k Pa,25.53 k Pa,24.75 k Pa,AUC are 0.824,0.913,0.874;the best cut-off value of Esd are 12.36 k Pa,12.82 k Pa,12.01 k Pa,AUC are 0.853,0.932,0.906,respectively.Whether "shell" take 1mm,2mm or 3 mm,the AUC of Emax is relatively maximum,Esd the second,statistically significant(P<0.05).When "shell" takes Emax of 2mm,a best cut-off value of58.76 k Pa,AUC area is maximum,the diagnostic efficiency is the best.Conclusion:1.Quantitative acquisition of the stiff values(Emax,Emean and Esd)in different thickness areas around thyroid nodules can be used as an effective method for differentiating benign and malignant thyroid nodules,and the Emax value is the best.2.When "shell" take the Emax of 2mm,the AUC area was the largest and the differential diagnosis efficiency was the best.Therefore,the maximum Young’s modulus of 2mm regions around thyroid nodules can improve the accuracy of sound touch elastography in the judgment of benign and malignant thyroid nodules.