ACR TI-RADS Overview
The ACR TI-RADS (Thyroid Imaging Reporting and Data System) is a points-based system for risk stratifying incidentally discovered thyroid nodules on ultrasound. Published by Tessler et al. in 2017, it assigns points across five sonographic categories and stratifies nodules into 5 risk levels (TR1–TR5).
TI-RADS Levels and Management
| Level | Points | Risk | FNA if ≥ | Follow-up if ≥ |
|---|---|---|---|---|
| TR1 — Benign | 0 | Benign | No FNA | No follow-up |
| TR2 — Not Suspicious | 2 | <2% | No FNA | No follow-up |
| TR3 — Mildly Suspicious | 3 | ~5% | ≥2.5 cm | ≥1.5 cm |
| TR4 — Moderately Suspicious | 4–6 | ~5–20% | ≥1.5 cm | ≥1 cm |
| TR5 — Highly Suspicious | ≥7 | >20% | ≥1 cm | ≥0.5 cm |
High-Risk Features (Suspicious for Malignancy)
Features most associated with malignancy: taller-than-wide shape (3 pts), punctate echogenic foci/microcalcifications (3 pts), very hypoechoic echogenicity (3 pts), extra-thyroidal extension (3 pts), lobulated/irregular margin (2 pts). Papillary thyroid cancers classically show microcalcifications and taller-than-wide morphology.
References
Tessler FN, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. J Am Coll Radiol. 2017;14(5):587–595.