Adult thyroid nodule on ultrasound
Score each nodule with ACR TI-RADS, then apply the size cut-offs for its TR level. Adults only.
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RadiologyDiagnostic
Thyroid Nodule Evaluation (ACR TI-RADS)
Thyroid Nodule Evaluation (ACR TI-RADS): Adult thyroid nodule on ultrasound → Check first: TSH, under 18, pregnancy, risk history → At any TR level: str...
Pathway Overview
16 steps
Algorithm Steps
16 total
01Start 02Warning Check first: TSH, under 18, pregnancy, risk history
Measure TSH in every patient with a nodule. Ask about childhood head and neck irradiation and family history of thyroid cancer or MEN 2: higher cancer risk, consider specialist review.
- Under 18 years: do not use TI-RADS size cut-offs. Decide FNA on US features and clinical context; seek paediatric specialist advice.
- Low (subnormal) TSH: radionuclide thyroid scan before FNA. A hot (hyperfunctioning) nodule does not need FNA.
- Pregnant or breastfeeding with low TSH: no radionuclide scan; seek endocrine advice.
03Warning At any TR level: stridor, suspicious node, local invasion or FDG uptake
Stridor or breathing difficulty: emergency department now (000 in Australia). Do not wait for scoring.
- Suspicious cervical lymph node: US-guided FNA of the node, whatever the TR level or nodule size.
- Extrathyroidal extension, vocal cord palsy, fixed or rapidly growing mass: urgent specialist referral.
- Focal FDG uptake on PET: higher cancer risk. FNA if 1 cm or more (ATA 2015), or MDT decision guided by the TR level.
04Action Composition (0-2 points)
Cystic or almost completely cystic 0; spongiform 0; mixed cystic and solid 1; solid or almost completely solid 2.
- Cystic, almost completely cystic or spongiform: TR1. Do not add points for other features.
- Spongiform: more than 50% of the nodule is small cystic spaces.
- Composition cannot be seen because of calcification: score as solid (2).
05Action Echogenicity (0-3 points)
Anechoic 0; hyperechoic or isoechoic 1; hypoechoic 2; very hypoechoic 3. Score the solid part.
- Compare with the adjacent thyroid tissue.
- Very hypoechoic: darker than the strap muscles.
- Anechoic applies only to cystic or almost completely cystic nodules.
- Cannot be determined: 1 point.
06Action Shape (0 or 3 points)
Wider-than-tall 0; taller-than-wide 3.
- Assess on a transverse image: height parallel to the US beam, width perpendicular to it.
07Action Margin (0-3 points)
Smooth 0; ill-defined 0; lobulated or irregular 2; extrathyroidal extension 3.
- Lobulated: protrusions into adjacent tissue. Irregular: jagged, spiculated or sharp angles.
- Obvious extrathyroidal extension: treat as malignant until proven otherwise.
- Margin cannot be determined: 0 points.
08Action Echogenic foci (add all that apply)
None or large comet-tail artefacts 0; macrocalcifications 1; peripheral (rim) calcifications 2; punctate echogenic foci 3.
- Add the points for each type present.
- Large comet-tail artefact: V-shaped, more than 1 mm, in a cystic part (0 points).
- Macrocalcifications cause acoustic shadowing.
09Decision Add all points: TI-RADS level
0 = TR1; 2 = TR2; 3 = TR3; 4-6 = TR4; 7 or more = TR5. No level has 1 point: mixed nodules score at least 2.
- 0 points
10End TR1 benign (0 points): no FNA, no follow-up
Also applies to all cystic, almost completely cystic and spongiform nodules.
- 2 points
11End TR2 not suspicious (2 points): no FNA, no follow-up
- 3 points
12Action TR3 mildly suspicious (3 points)
FNA if 2.5 cm or more. US follow-up if 1.5-2.4 cm at 1, 3 and 5 years. Under 1.5 cm: no FNA or follow-up.
13Action TR3-TR5: follow-up and multiple nodules
Apply to each nodule that needs FNA or US follow-up.
- Multiple nodules: FNA no more than 2, those with the highest TR level (not the largest).
- Significant growth: 20% or more in at least 2 dimensions (and at least 2 mm), or 50% or more in volume. FNA if the size cut-off is now met; if not, repeat US in 1 year.
- New suspicious features raise the TR level: apply the size cut-offs for the new level.
- Size stable for 5 years: stop US follow-up.
- FNA result: manage by Bethesda category.
14End Report TR level, size and plan for each nodule
Report up to 4 nodules with the highest TR levels. Include the cervical lymph node assessment.
- 4-6 points
15Action TR4 moderately suspicious (4-6 points)
FNA if 1.5 cm or more. US follow-up if 1.0-1.4 cm at 1, 2, 3 and 5 years. Under 1.0 cm: no FNA or follow-up.
- Path rejoins step 13Shared downstream outcome
- 7 or more points
16Action TR5 highly suspicious (7 or more points)
FNA if 1.0 cm or more. US follow-up if 0.5-0.9 cm every year for up to 5 years. 0.5-0.9 cm: FNA may be appropriate in some patients; decide with the patient and specialist (risk factors, life expectancy). Under 0.5 cm: no FNA or follow-up.
- Path rejoins step 13Shared downstream outcome
Guideline Source
ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee (Tessler FN et al., J Am Coll Radiol 2017;14:587-595)
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Adults only: TI-RADS size cut-offs are not validated in children and adolescents.
- The score does not replace clinical assessment: low TSH, stridor, suspicious lymph nodes, local invasion, focal FDG uptake or high-risk history change management.
- Does not apply to diffuse thyroid disease without a discrete nodule.
Contraindicated Populations
Children and adolescents under 18 years (TI-RADS size cut-offs not validated)
Applicable Regions
USAUUKEUKR
AU: No Australian-specific change to ACR TI-RADS scoring or FNA thresholds.
EU: EU-TIRADS (ETA 2017) uses different categories and FNA size cut-offs.
KR: K-TIRADS (Korean Society of Thyroid Radiology) is the local system in Korea.
UK: BTA/BAETS 2026 consensus accepts the BTA U score, ACR TI-RADS or EU-TIRADS; check which system the local report uses.
US: ACR TI-RADS 2017 is the ACR standard; ATA 2015 sonographic patterns are also widely used.
Version 2Next review: 2027-09-30
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Related Resources
Frequently Asked Questions
What is the Thyroid Nodule Evaluation (ACR TI-RADS)?
The Thyroid Nodule Evaluation (ACR TI-RADS) is a diagnostic clinical algorithm for Radiology. It provides a structured decision tree to guide clinical decision-making, based on ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee (Tessler FN et al., J Am Coll Radiol 2017;14:587-595).
What guideline is the Thyroid Nodule Evaluation (ACR TI-RADS) based on?
This algorithm is based on ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee (Tessler FN et al., J Am Coll Radiol 2017;14:587-595) (DOI: 10.1016/j.jacr.2017.01.046).
What are the limitations of the Thyroid Nodule Evaluation (ACR TI-RADS)?
Known limitations include: Adults only: TI-RADS size cut-offs are not validated in children and adolescents.; The score does not replace clinical assessment: low TSH, stridor, suspicious lymph nodes, local invasion, focal FDG uptake or high-risk history change management.; Does not apply to diffuse thyroid disease without a discrete nodule.. Individual patient factors may require deviation from these recommendations.
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