[Value of thyroid imaging reporting and data system and shear wave elastography for diagnosis of thyroid...

To investigate the value of each single and combined applications of ultrasound thyroid imaging reporting and data system (TI-RADS), ultrasonic shear wave elastography in the diagnosis of thyroid microcarcinoma (TMC).

323 patients with thyroid tiny nodules confirmed by surgery and pathology were analyzed prospectively. Then their TI-RADS and shear wave elastography features were summarized. SWE elasticity indices (mean, minimum and maximum value of interest) of nodules were measured. The surgical pathology results were regarded as the gold standard to calculate the sensitivity, specificity, accuracy, positive predictive value and negative predictive value of TI-RADS, shear wave elastography and their combination in the diagnosis of TMC. The receiver operating characteristic (ROC) curve of TI-RADS, shear wave elastography and combined application of both were drawn. The area under the ROC curve were calculated. Furthermore, the value of combined application of both examinations in the diagnosis of thyroid microcarcinoma (TMC) was investigated.

From 323 nodules,253 were thyroid carcinomas and 70 were benign. Areas under the ROC curves (AUC) of SWE parameters were 0. 648,0. 629 and 0. 605. For SWE, the optimal cut-off value according to ROC curve was SWE_max = 65.50 kPa and SWE_mean = 37.50 kPa. Generally, the sensitivity, specificity, accuracy, PPV and NPV were 88.14%, 82.86%, 87.00%, 94.89% and 65.91% for TI-RADS, and 49.01%, 74.29%, 54.49%, 87.32% and 28. 73% for SWE. There were statistically significant differences in the sensitivity, accuracy, PPV and no statistically significant differences in the specificity, and NPV. The sensitivity,specificity, accuracy, PPV and NPV were 95.26%, 67.14%, 89.16%, 91.29% and 79.66% for combined application of both. The area under the ROC curve of TI-RADS, shear wave elastography and their combination were 0.763, 0.616, 0.804. For nodules ≤ 5 mm, the sensitivity, specificity, accuracy, PPV and NPV were 91.67%, 66.67%, 87.07%, 92.44% and 64.29%. However, for nodules 5-10 mm,the sensitivity,specificity, accuracy, PPV and NPV were 98.50%, 67.44%, 90.91%, 90.34% and 93.55%.

The diagnose of TMC can be further improved by combined application of ultra-sonic TI-RADS and SWE.