Effect of the size of benign thyroid degenerative nodules on ACR TI-RADS categories

Purpose Our study aimed to identify ultrasound characteristics of benign thyroid degenerative nodules and reveal the correlation between their sizes and 2017 ACR Thyroid Imaging Reporting and Data System (TI-RADS) categories. Methods A total of 174 thyroid degenerative nodules were divided into three groups: 0.5–1 cm group (70 nodules), 1–2 cm group (27 nodules), and > 2 cm group (77 nodules). The ultrasound appearance of each nodule was evaluated, and the ACR TI-RADS scores and levels of the nodules were also calculated and compared among the three groups. Results The ultrasound appearance of degenerative nodules of different sizes is diversified, and the 0.5–1 cm group tended to have more malignant features and higher TI-RADS scores and categories. The scatterplot of Spearman correlation showed a significant negative correlation between the nodule sizes and TI-RADS categories. Conclusion The 2017 ACR TI-RADS, which recommends fine-needle aspiration according to the nodule size and category, is still useful in managing these nodules, and following the clinical recommendations of ACR TI-RADS is necessary.