How it works
ACR TI-RADS assigns points in five categories and sums them. Spongiform nodules score 0 and take no further points; a mixed nodule is scored on its solid component; if composition cannot be judged because of calcification assign 2 points, if echogenicity cannot be judged assign 1, and if the margin cannot be judged assign 0.
| Level | Points | FNA if | Follow-up if | Follow-up schedule |
|---|---|---|---|---|
| TR1 – benign | 0 | – | – | none |
| TR2 – not suspicious | 2 | – | – | none |
| TR3 – mildly suspicious | 3 | ≥ 2.5 cm | ≥ 1.5 cm | 1, 3 and 5 years |
| TR4 – moderately suspicious | 4–6 | ≥ 1.5 cm | ≥ 1.0 cm | 1, 2, 3 and 5 years |
| TR5 – highly suspicious | ≥ 7 | ≥ 1.0 cm | ≥ 0.5 cm | annually to 5 years |
- Size is the largest of the three dimensions. Use the same threshold for the whole nodule in mixed cystic and solid nodules.
- With several nodules, biopsy those with the highest TI-RADS level rather than the largest, and no more than two at a time.
- Growth on follow-up is a ≥ 20 % increase in at least two dimensions (minimum 2 mm) or a ≥ 50 % increase in volume. A nodule stable over 5 years needs no further imaging.
- A 1-point total (possible only for a cystic nodule with a macrocalcification) is not on the ACR chart; the calculator reports TR1, which like TR2 needs neither FNA nor follow-up.
References
- Tessler FN, Middleton WD, Grant EG, 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. doi:10.1016/j.jacr.2017.01.046
- Grant EG, Tessler FN, Hoang JK, et al. Thyroid Ultrasound Reporting Lexicon: White Paper of the ACR Thyroid Imaging, Reporting and Data System (TIRADS) Committee. J Am Coll Radiol. 2015;12(12 Pt A):1272–1279. doi:10.1016/j.jacr.2015.07.011
- Tessler FN, Middleton WD, Grant EG. Thyroid Imaging Reporting and Data System (TI-RADS): A User's Guide. Radiology. 2018;287(1):29–36. doi:10.1148/radiol.2017171240
- American College of Radiology. ACR TI-RADS assessment categories chart. www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Reporting-and-Data-Systems/TI-RADS