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.

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.

Why Use This ACR TI-RADS Calculator — Thyroid Nodule Risk Stratification?

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 This Calculator

  1. Select the composition observed on ultrasound.
  2. Select the echogenicity relative to thyroid parenchyma.
  3. Select the shape in the transverse plane.
  4. Select the margin type and echogenic foci.
  5. Enter the nodule size to review the ACR size-threshold context.

Formula

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 cm

Example 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

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

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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

Frequently Asked Questions

What is the most suspicious feature on thyroid ultrasound?

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.

Should every thyroid nodule be biopsied?

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.

What happens after a TI-RADS 5 nodule?

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.

Can a homogeneously solid isoechoic nodule still be cancer?

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.

Why do cystic and spongiform nodules score 0 points?

Those patterns are associated with low malignancy risk in the ACR framework, so they do not add suspicious-feature points.

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