ACR TI-RADS scores five ultrasound features of a thyroid nodule (composition, echogenicity, shape, margin, echogenic foci) and adds the points: 0 is TR1, 2 is TR2, 3 is TR3, 4 to 6 is TR4 and 7 or more is TR5. The category plus the nodule size decides whether fine-needle aspiration (FNA), follow-up or nothing is advised.
What is TI-RADS?
TI-RADS (Thyroid Imaging Reporting and Data System) is a standardised way to describe thyroid nodules on ultrasound and decide which ones need a needle biopsy. The American College of Radiology (ACR) published its scoring system in 2017. Instead of an overall impression, the radiologist scores five features, and the sum places the nodule in one of five categories. Most thyroid nodules are benign, and the system aims to avoid biopsies of the many harmless ones while not missing the suspicious ones.
The five features and their points
| Feature | Points |
|---|---|
| Composition | Cystic or spongiform 0 · mixed 1 · solid 2 |
| Echogenicity | Anechoic 0 · hyper-/isoechoic 1 · hypoechoic 2 · very hypoechoic 3 |
| Shape | Wider-than-tall 0 · taller-than-wide 3 |
| Margin | Smooth or ill-defined 0 · lobulated/irregular 2 · extra-thyroidal extension 3 |
| Echogenic foci | None or large comet-tail 0 · macrocalcifications 1 · peripheral 2 · punctate 3 (add all that apply) |
From points to a recommendation
| Level | Points | FNA if at least | Follow-up if at least |
|---|---|---|---|
| TR1 benign | 0 | No FNA | None |
| TR2 not suspicious | 2 | No FNA | None |
| TR3 mildly suspicious | 3 | 25 mm | 15 mm |
| TR4 moderately suspicious | 4 to 6 | 15 mm | 10 mm |
| TR5 highly suspicious | 7 or more | 10 mm | 5 mm (yearly, up to 5 years) |
The nodule size to use is the largest dimension. The size thresholds exist because small cancers, especially in low-risk categories, often grow slowly and can be observed safely.
Limits and context
The score is a risk estimate and must be read together with clinical history, family history, lymph nodes and the patient’s wishes. Europe also uses EU-TIRADS and in the Netherlands practice follows local guidelines, so the thresholds can differ. The tool reproduces the published ACR table to support clinicians and informed patients. It cannot diagnose cancer, and a TR5 result does not mean cancer is certain, only that biopsy is advised at that size.
For other clinical calculators on this site, see the QTc calculator.
How to use this calculator
- Select the finding for composition, echogenicity, shape and margin from the ultrasound report.
- Tick every type of echogenic focus that is present (points add up).
- Enter the largest nodule dimension in millimetres.
- Read the TR level and the size-based recommendation, and discuss it with the treating clinician.
Key figures at a glance
| Standard | ACR TI-RADS (2017) |
|---|---|
| Categories | TR1 to TR5 |
| FNA thresholds | TR3 ≥ 25 mm · TR4 ≥ 15 mm · TR5 ≥ 10 mm |
| Use | Clinical decision support, not diagnosis |
Frequently asked questions
TR4 means moderately suspicious, with 4 to 6 points. A biopsy is generally advised if the nodule is at least 15 mm, with follow-up from 10 mm.
No. It raises the probability, but most TR4 and many TR5 nodules are benign. A needle biopsy provides more certainty.
Add the points from composition, echogenicity, shape, margin and all types of echogenic foci present.
Dutch radiologists use ACR TI-RADS and EU-TIRADS, and the choice depends on the hospital and local guidance.
No. Treatment decisions are for your care team.