A Comparative Study Of Diagnostic Efficacy Between TI-RADS Combined With Stress-based Elastography And TI-RADS Combined With Shear-wave Elastography In The Differential Diagnosis Of Benign And Malignant Thyroid Nodules

Objective: To evaluate the effectiveness of the ACR version of TI-RADS category,stress-based elastography and shear-wave elastography in the differential diagnosis of benign and malignant thyroid nodules.To explore whether the addition of elastography can improve the diagnostic efficacy of the TI-RADS category alone in identifying benign and malignant thyroid nodules,and analyze which of the stress-based elastography and shear-wave elastography methods is a better aid.Methods: A total of 113 nodules were included from 113 patients who underwent thyroidectomy or fine needle aspiration(FNA)in our hospital from February 2017 to July 2018.Each case underwent routine two-dimensional ultrasonography,TI-RADS category of the 2017 ACR version,stress-based and shear-wave ultrasound elastography within one week prior to surgery.The ultrasound image features of the thyroid nodules,the TI-RADS category,and the stress-based elastography classification were independently analyzed and evaluated by two sonographers who did not know the pathological diagnoses.When there were inconsistencies,they negotiated to obtain uniform results.The final diagnoses of the target thyroid nodules were determined by surgical pathological diagnoses,clear FNA malignant pathological diagnoses or FNA benign pathological diagnoses plus follow-up.Classes 1-5 of the TI-RADS category of the thyroid target nodules were labeled as 1-5 points.Grade I-IV of the stress-based elastography method were labeled as 1-4 points.In the shear-wave elastography method,the Max,Mean and SWE-Ratio of the target nodules were obtained respectively.The final diagnoses of the nodules were compared,and the effectiveness of the TI-RADS category,two elastography methods and the combined methods in the differential diagnosis of benign and malignant thyroid nodules were evaluated by using univariate logistic regression analysis,constructing the receiver operating characteristic curve(ROCs),and using Bootstrap nonparametric method to compare the area under the curve.Results: 22 males and 91 females,aged 22-77 years old,with an average of(45.8±12.4)years old,were included.The maximum diameter of nodules was 5.4-38.6 mm,with an average of(14.8±7.8)mm.64 cases were confirmed as benign nodules and 49 cases were malignant nodules.There were statistical differences in the composition,echo,margin,shape,blood flow signal and whether there were focal strong echoes in benign and malignant thyroid nodules(P<0.05).With a diagnostic threshold of 4.5 point,the AUC of the TI-RADS category was 0.838,and the sensitivity,specificity,and accuracy were 0.796,0.797,and 0.796,respectively.With a diagnostic threshold of 2.5 point,the AUC of the stress-based ultrasound elastography was 0.907,and the sensitivity,specificity,and accuracy were 0.898,0.828,and 0.858,respectively.The longitudinal section SWE-Ratio method had the highest diagnostic efficiency in shear-wave elastography.With a diagnostic threshold of 2.25,the AUC was 0.782,and the sensitivity,specificity,and accuracy were 0.653,0.875,and 0.779,respectively.The AUC of the stress-based elastography is larger than that of the shear-wave elastography(P=0.006).The AUC of TI-RADS category combined with stress-based elastography was 0.940,and the sensitivity,specificity and accuracy were 0.776,0.938,and 0.867,respectively.The AUC of TI-RADS category combined with shear-wave elastography was 0.917,and the sensitivity,specificity and accuracy were 0.980,0.766,and 0.850,respectively.Both the AUC of TI-RADS category combined with stress-based elastography and the AUC of TI-RADS category combined with shear-wave elastography were compared with the AUC of the TI-RADS category alone,P < 0.05.However,there was no statistical difference in the AUC between TI-RADS category combined with stress-based elastography and TI-RADS category combined with shear-wave elastography,P>0.05.Conclusions:(1)Solid compositon,hypoechogenicity,marginal irregularity,A/T>1 and microcalcification are associated with papillary thyroid carcinoma.The ACR version of TI-RADS category has a high diagnostic efficacy for the differential diagnosis of benign and malignant thyroid nodules.(2)Stress-based elastography or shear-wave elastography can be used as a good auxiliary method.Both the combination of the two with the ACR version of the TI-RADS category can improve the diagnostic efficacy of using TI-RADS category alone in the differential diagnosis of benign and malignant thyroid nodules.Both of the two elastography methods have the potential to further improve the diagnostic efficacy of ultrasound in differentiating benign and malignant thyroid nodules.(3)There is no statistical difference in the diagnostic efficacy of the two elastography methods combined with the TI-RADS category,suggesting that when the TI-RADS category is routinely used for the differential diagnosis of thyroid nodules,we can apply each of the two elastography methods to provide useful information for identifying benign and malignant thyroid nodules.