Thyroid nodule malignancy risk stratification and fine-needle aspiration or follow-up recommendations based on ACR TI-RADS.
Text summary of the rules this calculator applies, generated from the same definitions the calculation uses.
Thyroid nodule malignancy risk stratification and fine-needle aspiration or follow-up recommendations based on ACR TI-RADS.
This system was designed for solid or predominantly solid thyroid nodules; its application may be limited in purely cystic nodules or those with extensive calcification obscuring assessment.
| Variable | Definition | Possible values | Unit |
|---|---|---|---|
| Composition | Proportion of solid vs. cystic tissue in the nodule. Choose only the predominant component if mixed. | Cystic or almost completely cystic (0 pt) · Spongiform (0 pt) · Mixed cystic and solid (1 pt) · Solid or almost completely solid (2 pt) | Categorical (points) |
| Echogenicity | Echogenicity of the solid component compared to adjacent thyroid parenchyma (not applicable to purely cystic/spongiform nodules). | Anechoic (0 pt) · Hyperechoic or isoechoic (1 pt) · Hypoechoic (2 pt) · Very hypoechoic (3 pt) | Categorical (points) |
| Shape | Assess on the transverse plane: if the AP diameter is greater than the transverse diameter ("taller than wide"), this is a suspicious sign. | Wider than tall (0 pt) · Taller than wide (3 pt) | Categorical (points) |
| Margin | The nodule's borders relative to the gland. Frank extrathyroidal extension is the highest-scoring finding. | Smooth (0 pt) · Ill-defined (0 pt) · Lobulated or irregular (2 pt) · Extrathyroidal extension (3 pt) | Categorical (points) |
| Echogenic foci (sum all that apply) — several can be selected | Unlike the other categories, multiple foci can be checked here and their points are added together. | None or large comet-tail artifact (0 pt) · Macrocalcifications (1 pt) · Peripheral (rim) calcifications (2 pt) · Punctate echogenic foci (3 pt) | Categorical (points) |
The TI-RADS score is calculated by summing points across 5 categories (composition, echogenicity, shape, margin, echogenic foci); a higher score means greater suspicion for malignancy.
| Criterion | Option | Points |
|---|---|---|
| Composition | Cystic or almost completely cystic | 0 |
| Composition | Spongiform | 0 |
| Composition | Mixed cystic and solid | 1 |
| Composition | Solid or almost completely solid | 2 |
| Echogenicity | Anechoic | 0 |
| Echogenicity | Hyperechoic or isoechoic | 1 |
| Echogenicity | Hypoechoic | 2 |
| Echogenicity | Very hypoechoic | 3 |
| Shape | Wider than tall | 0 |
| Shape | Taller than wide | 3 |
| Margin | Smooth | 0 |
| Margin | Ill-defined | 0 |
| Margin | Lobulated or irregular | 2 |
| Margin | Extrathyroidal extension | 3 |
| Echogenic foci (sum all that apply) | None or large comet-tail artifact | 0 |
| Echogenic foci (sum all that apply) | Macrocalcifications | 1 |
| Echogenic foci (sum all that apply) | Peripheral (rim) calcifications | 2 |
| Echogenic foci (sum all that apply) | Punctate echogenic foci | 3 |
The decision to perform FNA (fine-needle aspiration) depends on both the TI-RADS category and nodule size (see management table). TR1-TR2 nodules do not require FNA regardless of size.
| Category | Points (points) | Malignancy risk | FNA | Follow-up |
|---|---|---|---|---|
| TR1 | 0 | Benign | No | No |
| TR2 | 1–2 | Not suspicious | No | No |
| TR3 | 3 | Mildly suspicious (2-5%) | ≥ 2.5 cm | ≥ 1.5 cm |
| TR4 | 4–6 | Moderately suspicious (5-20%) | ≥ 1.5 cm | ≥ 1.0 cm |
| TR5 | ≥ 7 | Highly suspicious (>20%) | ≥ 1.0 cm | ≥ 0.5 cm |
| Category | Meaning | Recommendation |
|---|---|---|
| TR1 | Benign | No FNA |
| TR2 | Not suspicious | No FNA |
| TR3 | Mildly suspicious | FNA if ≥ 2.5 cm. Follow-up if ≥ 1.5 cm |
| TR4 | Moderately suspicious | FNA if ≥ 1.5 cm. Follow-up if ≥ 1.0 cm |
| TR5 | Highly suspicious | FNA if ≥ 1.0 cm. Follow-up if ≥ 0.5 cm |