ACR TI-RADS Calculator (Thyroid Nodule)
Select one option from each ultrasound feature category, then enter the largest nodule size in centimeters to get the TI-RADS score, TR level, and suggested management.
The TI-RADS calculator below helps translate thyroid ultrasound findings into a standardized score and risk category. TI-RADS (Thyroid Imaging Reporting and Data System) is commonly used to reduce unnecessary biopsies while still identifying nodules that deserve closer attention.
What is TI-RADS?
TI-RADS is a point-based framework for characterizing thyroid nodules. Instead of relying on a vague “looks suspicious” impression, each ultrasound feature contributes a defined number of points. The total determines a category (TR1 to TR5), which then connects to size-based recommendations for follow-up imaging or fine needle aspiration (FNA).
In practice, this approach improves communication between radiologists, endocrinologists, surgeons, and primary care teams. It also helps patients understand why one nodule is monitored while another is biopsied.
How the TI-RADS score is calculated
ACR TI-RADS assigns points across five groups of nodule features. You add the points from each group:
- Composition (cystic, mixed, or solid)
- Echogenicity (anechoic, isoechoic, hypoechoic, etc.)
- Shape (wider-than-tall vs taller-than-wide)
- Margin (smooth, irregular, extra-thyroidal extension)
- Echogenic foci (calcification patterns and punctate foci)
After obtaining the total point value, the nodule is mapped to a TI-RADS level:
| Total Points | Category | Interpretation | Approximate Malignancy Risk |
|---|---|---|---|
| 0 | TR1 | Benign | Very low (~0.3%) |
| 1-2 | TR2 | Not suspicious | Low (~1.5%) |
| 3 | TR3 | Mildly suspicious | Low-moderate (~4.8%) |
| 4-6 | TR4 | Moderately suspicious | Moderate (~9.1%) |
| 7+ | TR5 | Highly suspicious | Higher (~35%) |
Size thresholds matter as much as category
A key point in TI-RADS: management decisions are not based on ultrasound appearance alone. Nodule size changes what to do next.
- TR1 / TR2: No FNA generally recommended.
- TR3: Follow-up if ≥1.5 cm, FNA if ≥2.5 cm.
- TR4: Follow-up if ≥1.0 cm, FNA if ≥1.5 cm.
- TR5: Follow-up if ≥0.5 cm, FNA if ≥1.0 cm.
This dual approach (risk + size) helps avoid over-biopsy of low-risk nodules while still identifying higher-risk lesions at clinically relevant sizes.
Step-by-step use of this TI-RADS calculator
1) Enter ultrasound features exactly as reported
Use the radiology report terms where possible. If the report says “solid hypoechoic taller-than-wide with punctate echogenic foci,” the corresponding point score will rise quickly.
2) Enter the maximum diameter in centimeters
Management thresholds are size-driven, so entering the correct maximum dimension is essential. For multi-dimensional measurements, use the largest value.
3) Review output: score, category, and recommendation
The calculator provides a practical summary: TI-RADS points, TR classification, estimated risk context, and whether current size meets follow-up or FNA criteria.
Example interpretation
Suppose a nodule has these findings:
- Solid composition (2)
- Hypoechoic (2)
- Taller-than-wide (3)
- Lobulated margin (2)
- Punctate echogenic foci (3)
Total = 12 points, which is TR5. If this nodule is 1.2 cm, it is above the TR5 FNA threshold (≥1.0 cm), so biopsy is generally recommended.
Important limitations and clinical context
- TI-RADS is a decision support framework, not a diagnosis.
- Patient history (radiation exposure, family history, symptoms) can shift management.
- Some nodules are better assessed with complementary tools, repeat imaging, or specialist input.
- Institutional protocols and clinician judgment may vary.
If your result suggests biopsy or close follow-up, discuss it directly with your endocrinologist or radiologist so the decision includes your full medical context.
FAQ
Is TR5 always cancer?
No. TR5 means higher suspicion, not certainty. Many TR5 nodules are benign, but they deserve closer evaluation based on size and clinical factors.
Can a low TI-RADS category still be monitored?
Yes. Clinicians may still monitor low-risk nodules depending on growth, compressive symptoms, patient preference, or prior imaging trends.
Do all thyroid nodules need biopsy?
No. One of TI-RADS’ goals is to reduce unnecessary procedures by reserving FNA for nodules that meet both risk and size criteria.