Suggested amendment of TI-RADS classification of thyroid nodules by shear wave elastography.

ABSTRACT

BACKGROUND: The application of the ultrasound elastography and Thyroid Imaging Reporting and Data System (TI-RADS) classification further expands the scope of ultrasound differential diagnosis between benign and malignant thyroid nodules. PURPOSE: To investigate the value of the quantitative parameter of ultrasonic shear waves in optimizing the TI-RADS classification of thyroid nodules. MATERIAL AND METHODS: A total of 168 thyroid nodules, initially classified using TI-RADS and scanned by shear wave elastography (SWE), were retrospectively analyzed. All cases were diagnosed by fine needle aspiration and histology following surgery. RESULTS: The benign rate of TI-RADS 3 nodules was 76.5%, while the benign rate of TI-RADS 4a nodules was 71.7%. Furthermore, the malignant rate of TI-RADS 4b nodules was 69.7%, while the malignant rate of TI-RADS 4c nodules was 85.7%. In differentiating benign from malignant nodules, the combination of TI-RADS classification and Emean had the largest area under the receiver operating characteristic curve (AUC). Using an Emean value of 42.25 kpa as the cut-off point, the malignant rate of TI-RADS 4a nodules decreased from 28.3% to 23.5%, while the malignant rate of TI-RADS 4b nodules increased from 69.7% to 79.4%. Compared to conventional ultrasound alone, the sensitivity, negative predictive value, and AUC of conventional ultrasound combined with SWE in the diagnosis of benign and malignant thyroid nodules significantly improved (P=0.012, 0.029, 0.001). CONCLUSION: The SWE technique can be used to further determine the benign and malignant nature of TI-RADS 4 lesions, providing further reference for the choice of clinical treatment. The TI-RADS classification system corrected by SWE is more significant in the diagnosis of benign and malignant thyroid nodules.