The Diagnostic Value Of ACR TI-RADS Classification Combined With Real Time Shear Wave Elastography Towards Thyroid Micro-nodules

Objective:To evaluate the diagnostic value of American College of Radiology(ACR)thyroid imaging reporting and data system(TI-RADS)combined with real time shear wave elastography(RT-SWE)towards thyroid micro-nodules.Methods:The image features of ACR TI-RADS classification and RT-SWE image characteristics of thyroid micro-nodules(249 nodules in total)in 172 patients were retrospectively analyzed,and the characteristics of all nodules were confirmed by surgery and pathology.The surgical pathology results were regarded as standard to draw the receiver operating characteristic(ROC)curve and calculated the area under curve(AUC),then obtained the optimal threshold value(including Emax,Emean and Emin)in the diagnosis of benign and malignant thyroid micro-nodules.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of ACR TI-RADS classification 、 RT-SWE and their combined application in the benign and malignant diagnosis of thyroid micro-nodules were analyzed,we could draw the ROC curve,calculated the AUC,and analyzed the diagnostic results of the three methods consistently with the pathological results.Results:From 249 thyroid micro-nodules,173 malignant micro-nodules and 76 benign micro-nodules were diagnosed by pathology.The sensitivity was 84.39%、specificity was78.94%、accuracy was 82.73%、positive predictive value was 90.12%、negative predictive value was 68.97% of ACR TI-RADS classification in the diagnosis of benign and malignant thyroid micro-nodules,and the Kappa value was 0.609.The AUC of Emax、Emean and Emin were 0.928、0.869 and 0.695 respectively.While the optimal threshold Emax was 29.9kpa,the sensitivity was 94.79%、specificity was 86.84%、accuracy was92.36%、positive predictive value was 94.25%、negative predictive value was 88.00% of RT-SWE in the diagnosis of benign and malignant thyroid micro-nodules,and the Kappa value was 0.809.The sensitivity was 94.79% 、 specificity was 92.10%,accuracy was93.98%、positive predictive value was 96.47%、negative predictive value was 88.61% of the two methods combined in the diagnosis of benign and malignant thyroid micronodules,and the Kappa value was 0.854.The AUC of ACR TI-RADS classification,RT-SWE and their combined application in the diagnosis of thyroid micro-nodules were0.804、0.915 and 0.941 respectively.The AUC of combined diagnosis was significantly greater than that of ACR TI-RADS classification or RT-SWE diagnosis alone,and the difference was statistically significant(P < 0.01).Conclusion:Both ACR TI-RADS classification and RT-SWE both had high diagnostic efficiency,and the combination of these two methods could further improve the diagnostic level of thyroid micro-nodules.