TIRADS (Thyroid Imaging Reporting and Data System): ACR standardized classification for thyroid nodule ultrasound features; TR1–TR5 risk categories guide FNA biopsy decisions based on malignancy suspicion.
TIRADS is a standardized ultrasound classification system for thyroid nodules that stratifies malignancy risk and guides fine-needle aspiration (FNA) biopsy decisions. The ACR TIRADS assigns points for composition, echogenicity, shape, margin, and echogenic foci. Scores correspond to TR1 (benign) through TR5 (high suspicion), with FNA thresholds based on both score and nodule size.