Thyroid Nodule Classification by Ultrasound: TI-RADS A to Z

Abstract

Thyroid cancer screening tripled from 1975 to 2009, whereas mortality due to thyroid cancer has not significantly changed, suggesting an overdiagnosis of thyroid cancer. Thyroid nodules are typically first assessed with ultrasound and followed up with fine needle aspiration (FNA), if indicated. Thyroid imaging reporting and data system (TI-RADS) is designed to improve diagnostic accuracy and risk stratification, leading to a decrease in unnecessary FNA procedures and follow-up examinations. TI-RADS assigns scores in five categories-composition, echogenicity, shape, margins, and echogenic foci-which are totaled to yield a final overall TI-RADS score and classification. The final classification has been shown to correlate with the likelihood of malignancy.