Advantages of the Korean Thyroid Imaging Reporting and Data System Combined with Contrast-Enhanced Ultrasound in Diagnosing Papillary Thyroid Microcarcinoma

Abstract

Background:A papillary thyroid microcarcinoma (PTMC) may have the characteristics of different types of lesions, usually leading to preoperative ultrasound diagnosis. Therefore, new diagnostic methods need to be developed. Objectives: This study aimed to evaluate the advantages of the Korean thyroid imaging reporting and data system (TI-RADS) combined with contrast-enhanced ultrasound (CEUS) in diagnosing PTMC. Patients and Methods: In total, 143 patients who had a total of 150 micro space-occupying lesions of the thyroid and underwent conventional ultrasonography (US) and CEUS were enrolled. The diagnostic value of the benign nodule and PTMC by TI-RADS, CEUS and combined method were compared. The independent US and CEUS predictors for PTCM were determined and quantified using logistic regression analysis. Results: The TI-RADS + CEUS combination had the highest accuracy (95.10%), sensitivity (96.74%), specificity (94.83%), positive prediction value (87.92%) and negative prediction value (98.02%), significantly greater than that of TI-RADS alone (area under the curve [AUC]: 0.930 vs. 0.873, P < 0.001; accuracy: 95.10% vs. 89.78%, P = 0.032; sensitivity: 96.74% vs. 86.05%, P = 0.041; positive predictive value [PPV]: 87.92% vs. 76.47%, P = 0.029) and CEUS alone (AUC: 0.930 vs. 0.857, P < 0.001; accuracy: 95.10% vs. 86.93%, P < 0.001; negative predictive value [NPV]: 98.02% vs. 90.83%, P = 0.047). Multivariate stepwise logistic regression showed that calcification (odds ratio [OR] = 1.586; 95% confidence interval [CI]: 1.037 -2.311; P = 0.027), hypoechogenicity (OR = 1.432; 95%CI: 0.975 -1.925; P = 0.035), and hypo-enhancement (OR = 2.140; 95%CI: 1.237 -2.840; P = 0.019) were the optimal predictor for PTMC. Conclusion: TI-RADS in combination with CEUS has superior diagnostic efficiency in the discrimination of micro-thyroid spaceoccupying lesions, which can improve the diagnostic accuracy of PTMC.