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ACR TI-RADS Calculator — Thyroid Nodule Risk Stratification
Score thyroid nodules using ACR TI-RADS, with point breakdown, TI-RADS level, and FNA/follow-up reference thresholds rather than a stand-alone biopsy decision.
⚠️ Clinical Tool: ACR TI-RADS scoring should be performed by a radiologist interpreting thyroid ultrasound. This calculator assists with point tabulation and size-threshold review but does not replace formal imaging interpretation.
Ultrasound Features
TI-RADS Level⧉
TR4 — Moderately Suspicious
4 points
FNA / Follow-up Reference⧉
FNA recommended (≥ 1.5 cm)
Based on TR4 + size
Malignancy Risk⧉
5–20%
TR4
Total Points⧉
4
Sum of 5 feature categories
ACR TI-RADS: TR4 (Moderately Suspicious) — 4 points
FNA recommended (≥ 1.5 cm) | Malignancy risk estimate: 5–20%
Point Breakdown
| Category | Feature Selected | Points |
|---|---|---|
| Composition | Solid or almost completely solid | 2 |
| Echogenicity | Hypoechoic | 2 |
| Shape | Wider than tall | 0 |
| Margin | Smooth | 0 |
| Echogenic Foci | None or large comet-tail artifacts | 0 |
| Total | 4 | |
ACR TI-RADS Classification
| Level | Points | Description | Malignancy | FNA Threshold |
|---|---|---|---|---|
| TR1 | 0 | Benign | < 2% | No FNA |
| TR2 | 2 | Not Suspicious | < 2% | No FNA |
| TR3 | 3 | Mildly Suspicious | ~5% | ≥ 2.5 cm FNA; ≥ 1.5 cm follow |
| TR4 | 4–6 | Moderately Suspicious | 5–20% | ≥ 1.5 cm FNA; ≥ 1.0 cm follow |
| TR5 | ≥ 7 | Highly Suspicious | > 20% | ≥ 1.0 cm FNA; ≥ 0.5 cm follow |
Planning notes, formulas, and examples
About the ACR TI-RADS Calculator — Thyroid Nodule Risk Stratification
The ACR Thyroid Imaging Reporting and Data System (TI-RADS) is a standardized framework for risk-stratifying thyroid nodules on ultrasound. It assigns points for composition, echogenicity, shape, margins, and echogenic foci, then translates the total into a TI-RADS level and a size-based reference threshold for follow-up or FNA review.
Thyroid nodules are common, while malignancy is much less common. The value of TI-RADS is that it helps organize the ultrasound features consistently so not every incidental nodule is treated the same way.
This calculator is most useful as a point-tabulation worksheet. Formal imaging interpretation, local radiology practice, thyroid history, and cytology still matter when deciding whether a nodule actually proceeds to biopsy or surveillance.
When This Page Helps
TI-RADS is useful because it turns a descriptive ultrasound impression into a repeatable point total. This calculator reduces arithmetic mistakes and makes the size-threshold context explicit, but it should still be read as a radiology worksheet rather than a biopsy order set.
How to Use the Inputs
- Select the composition observed on ultrasound.
- Select the echogenicity relative to thyroid parenchyma.
- Select the shape in the transverse plane.
- Select the margin type and echogenic foci.
- Enter the nodule size to review the ACR size-threshold context.
Formula used
TI-RADS Points = Composition (0-2) + Echogenicity (0-3) + Shape (0-3) + Margin (0-3) + Echogenic Foci (0-3)
TR1: 0 pts | TR2: 2 pts | TR3: 3 pts | TR4: 4-6 pts | TR5: ≥ 7 pts
FNA reference thresholds: TR3 ≥ 2.5 cm | TR4 ≥ 1.5 cm | TR5 ≥ 1.0 cmExample Calculation
Result: TI-RADS TR5 (7 points) — FNA reference threshold met on this worksheet
Solid (2) + hypoechoic (2) + wider-than-tall (0) + smooth (0) + punctate echogenic foci (3) = 7 points, which maps to TR5. At 15 mm, the nodule is above the common ACR TR5 FNA size threshold of 1.0 cm.
Tips & Best Practices
- Score each feature category independently rather than relying on overall gestalt alone.
- Taller-than-wide shape is assessed in the transverse plane.
- If more than one feature exists in the same category, score the most suspicious one in that category.
- Cross-sectional imaging cannot replace dedicated thyroid ultrasound feature scoring.
Why TI-RADS Helps
The main advantage of TI-RADS is consistency. It gives radiologists and clinicians a shared vocabulary for describing how suspicious a nodule looks and when size starts to matter.
Suspicion and Size Work Together
The ACR system does not rely on suspicion score alone. A lower-risk nodule generally needs to be larger before FNA enters the conversation, while a higher-risk nodule can cross the threshold at a smaller size.
Use the Score as Imaging Context
TI-RADS is part of the radiology interpretation layer. Patient history, prior growth, compressive symptoms, thyroid function, cytology, and endocrinology follow-up still determine what actually happens next.
Sources & Methodology
Last updated:
Methodology
This page assigns points across the five ACR TI-RADS feature groups, sums the total, and maps the result to TR1 through TR5. When a nodule size is entered, it compares that size with the ACR follow-up and FNA threshold bands so the imaging finding can be reviewed in the same framework used in the white paper.
The result is an ultrasound risk-stratification worksheet, not a stand-alone biopsy order. Endocrine history, interval growth, prior cytology, compressive symptoms, thyroid function, and clinician judgment still matter beyond the TI-RADS category itself.
Sources
- ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee (PubMed / Journal of the American College of Radiology) — Primary ACR TI-RADS paper defining the point system and follow-up/FNA thresholds.
- ACR TI-RADS FAQ (American College of Radiology) — Official ACR implementation notes and practical clarifications for TI-RADS use.
Frequently Asked Questions
Taller-than-wide shape and punctate echogenic foci contribute the most points individually. They are high-signal features in the ACR system, though the full score still depends on the rest of the nodule.
No. TI-RADS is designed partly to reduce unnecessary biopsies by pairing feature-based suspicion with size thresholds. Many nodules fall into follow-up or no-FNA ranges.
TI-RADS describes imaging suspicion, not cytology. If FNA is performed, the next step depends on the cytology result, prior imaging, symptoms, and endocrinology or surgical context.
Yes. A solid isoechoic nodule with otherwise bland features can still land in TR3 and still be malignant, which is one reason TI-RADS is a structured risk system rather than a binary benign/malignant label.
Those patterns are associated with low malignancy risk in the ACR framework, so they do not add suspicious-feature points.
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