A Comparative Analysis of TIRADS and ATA Classification Systems in Determining the Malignancy of Thyroid Nodules

The present study aims to compare the diagnostic performance of two ultrasound classifications of thyroid nodules: 2015 American Thyroid Association (ATA) guidelines and 2017 American College of Radiology (ACR) Thyroid Imaging, Reporting and Data System (TI-RADS). This comparison evaluates the association of these classifications with the Bethesda system regarding the malignancy of thyroid nodules. A total of 166 patients who met the study's inclusion criteria were enrolled. Ultrasound examinations of the thyroid nodules were conducted, along with fine-needle aspiration (FNA) from the thyroid nodules, with subsequent submission to pathology. The mean age of the patients was 49.79 ± 15.61 years, and 84.3% of participants were female. The Bethesda category 2, with a frequency of 55.42%, was the most observed. 78.3% had solid nodules, with 48.2% showing isoechogenicity. The average nodule size was 22.56 ± 11.05 mm. The most frequent ATA and TI-RADS classifications were low (50.6% and 47.6%, respectively). Significant correlations were found between the Bethesda and TI-RADS scores (p < 0.001), the Bethesda and ATA scores (p < 0.001), and the ATA and TI-RADS scores (p < 0.001). The sensitivity of ATA and TI-RADS was 43% and 47%, respectively, with specificities of 98% and 98%. Both classification systems represent valuable tools for assessing thyroid nodule malignancy.