TI-RADS Calculator: What Your TR1-TR5 Score Means + Biopsy Decision
Most thyroid nodules show up by accident. A neck ultrasound, an MRI for an unrelated reason, a hand on your throat in the shower. Your radiologist hands back a report with a “TR” score from 1 to 5, and the next thing you do is Google what that means and whether you need a biopsy. This calculator answers both questions in under a minute[1].
It runs your ultrasound features through both major thyroid nodule classification systems at the same time: the ACR TI-RADS scoring system and the ATA sonographic pattern system.
Here’s how to use it:
Grab your thyroid ultrasound report and enter the nodule size and other features described by your radiologist. The calculator then gives you your risk and recommended next steps. It’s that easy.
Note: This calculator is decision support, not a diagnosis. Final biopsy and management decisions belong to your radiologist, endocrinologist, or surgeon, who will integrate clinical context this tool cannot capture, including growth on serial imaging, lymph node findings, family history, and personal cancer history.
TI-RADS Calculator
Enter your thyroid ultrasound features below. The calculator scores your nodule with both the ACR TI-RADS system (TR1 through TR5) and the ATA Sonographic Pattern at the same time, with side-by-side biopsy recommendations.
| Category | Score | Risk Level | Malignancy | FNA Size | Follow-Up Size |
|---|---|---|---|---|---|
| TR1 | 0 | Benign | ~0.3% | No FNA | None |
| TR2 | 1–2 | Not Suspicious | ~1.5% | No FNA | None unless clinically indicated |
| TR3 | 3 | Mildly Suspicious | ~4.8% | ≥ 2.5 cm | 1.5–2.4 cm: years 1, 3, 5 |
| TR4 | 4–6 | Moderately Suspicious | ~9.1% | ≥ 1.5 cm | 1.0–1.4 cm: years 1, 2, 3, 5 |
| TR5 | ≥ 7 | Highly Suspicious | ~35% | ≥ 1.0 cm | 0.5–0.9 cm: annually × 5 years |
| Pattern | Malignancy Risk | FNA Size Threshold |
|---|---|---|
| Benign | < 1% | No FNA (pure cyst) |
| Very Low Suspicion | < 3% | ≥ 2.0 cm or observation |
| Low Suspicion | 5–10% | ≥ 1.5 cm |
| Intermediate Suspicion | 10–20% | ≥ 1.0 cm |
| High Suspicion | 70–90% | ≥ 1.0 cm (consider ≥ 0.5 cm if subcapsular or with abnormal lymph nodes) |
Written and medically reviewed by Dr. Westin Childs, D.O. Last reviewed: May 10, 2026.
How to Use This Calculator
Step #1: Enter Your Nodule Size
This is the largest dimension of your nodule, in centimeters or millimeters.
Your ultrasound report will list three dimensions (length x width x depth). Use the largest one.
The size of your nodule determines the FNA biopsy threshold for both systems.
Step #2: Pick Your Composition
Your radiologist will describe your nodule as cystic, spongiform, mixed cystic or solid, or solid. Cystic nodules are filled with fluid and are almost never cancerous.
Spongiform nodules are clusters of tiny cystic spaces filling more than half the nodule volume and have a malignancy risk under 3 percent[2].
Solid nodules carry the highest cancer risk because most thyroid cancers (papillary, follicular, medullary) appear as solid masses. For mixed cystic-solid nodules, evaluate the solid portion’s features for the rest of the calculator inputs because that’s where any cancer would be located.
Step #3: Pick Your Echogenicity
The echogenicity refers to how dark or bright your nodule appears on ultrasound, compared to the surrounding tissues.
Anechoic means it shows no echoes, which is typical for pure cysts.
Hyperechoic means it appears brighter than thyroid tissue.
Isoechoic means it appears the same brightness as thyroid tissue.
Hypoechoic means it appears darker than thyroid tissue, which is concerning for cancer because most papillary thyroid carcinomas are hypoechoic[1].
Very hypoechoic means it appears darker than the strap muscles in your neck, which has high specificity for cancer (low rate of false positives)[4].
Step #4: Pick Shape, Margin, and Echogenic Foci
These are additional features that your radiologist will use to describe your nodule, and each imparts a different risk:
- The shape is wider-than-tall (oval or round, the benign pattern) or taller-than-wide (a strong single indicator of malignancy with specificity around 82 to 93 percent)[5].
- The margin is the edge of the nodule, scored as smooth, ill-defined, lobulated, or irregular, or extra-thyroidal extension (which always means invasive malignancy because the nodule has broken through the thyroid capsule).
- Echogenic foci are the bright spots inside the nodule.
- None or comet-tail artifacts are reassuring.
- Microcalcifications (punctate echogenic foci, dot-like, less than 1mm) carry the highest specificity for cancer because they’re often the calcified remnants of papillary thyroid carcinoma’s psammoma bodies[1].
Step #5: Add Optional Clinical Modifiers
You have the option to check four additional modifier boxes to further refine your results.
This includes: suspicious cervical lymph nodes, a family history of thyroid cancer, a personal history of head and neck radiation, and the presence of multiple nodules.
Check each one that applies to your situation to improve your accuracy.
Understanding Your Results
Your ACR TI-RADS Score (TR1 through TR5)
The ACR TI-RADS panel returns a numeric score (the sum of points across the 5 features) and a TR level. TR1 (0 points) is Benign with a malignancy risk of around 0.3 percent and no FNA or follow-up required. TR2 (1 to 2 points) is Not Suspicious with a malignancy risk around 1.5 percent and no FNA needed. TR3 (3 points) is Mildly Suspicious with a malignancy risk of around 4.8 percent, FNA at 2.5 cm or larger, follow-up ultrasound at 1.5 to 2.4 cm. TR4 (4 to 6 points) is Moderately Suspicious with a malignancy risk around 9.1 percent, FNA at 1.5 cm or larger, follow-up at 1.0 to 1.4 cm. TR5 (7 or more points) is Highly Suspicious with a malignancy risk around 35 percent, FNA at 1.0 cm or larger, follow-up at 0.5 to 0.9 cm annually for 5 years[1].
Your ATA Sonographic Pattern
The ATA panel returns a categorical pattern. Benign means a pure cyst with malignancy risk under 1 percent and no FNA needed. Very Low Suspicion (spongiform or partially cystic without suspicious features) is under 3 percent risk, FNA at 2.0 cm or larger or observation. Low Suspicion (iso/hyperechoic solid or partially cystic with eccentric solid) is 5 to 10 percent risk, FNA at 1.5 cm or larger. Intermediate Suspicion (hypoechoic solid with smooth margins) is 10 to 20 percent risk, FNA at 1.0 cm or larger. High Suspicion (hypoechoic solid with at least one suspicious feature like irregular margins, microcalcifications, taller-than-wide shape, or extra-thyroidal extension) is 70 to 90 percent risk, FNA at 1.0 cm or larger (sometimes 0.5 cm if subcapsular or with abnormal lymph nodes)[2].
Why the Two Systems Sometimes Disagree
ACR TI-RADS adds points across 5 categories, then maps the total to a TR level with a size-based biopsy threshold. ATA walks a categorical decision tree based on composition and echogenicity, then asks whether suspicious features are present. The two systems weigh individual ultrasound features differently and use different size cutoffs for FNA. Studies comparing the two head-to-head report concordance around 70 to 80 percent, which means roughly 1 in 4 nodules gets a different recommendation depending on which system is used[3][6].
The most common true disagreement is the subcentimeter hypoechoic solid nodule. ACR scores it as TR4 (Moderately Suspicious) but doesn’t recommend FNA below 1.5 cm. ATA classifies the same nodule as Intermediate Suspicion and recommends FNA at 1.0 cm or larger. If your nodule lands in this range, both reads are technically correct. The decision depends on your tolerance for the small risk of missing an early cancer versus the small risk of a non-diagnostic biopsy. Bring both results to your endocrinologist and have the conversation explicitly.
The Multiple-Nodule FNA Limit
If you have multiple nodules (multinodular goiter), ACR recommends FNA on no more than the 2 highest-scoring nodules at any one biopsy session, and surveillance follow-up on no more than the 4 highest-scoring nodules. This rule prevents over-biopsy in patients with diffuse multinodular disease while making sure the most concerning nodules get evaluated. Most patients with multiple nodules don’t need every nodule biopsied, even if several look mildly suspicious on ultrasound[1].
Beyond the Nodule: The Functional Layer
Most thyroid nodules are not cancerous.
The vast majority are benign hyperplastic nodules, colloid nodules, or Hashimoto’s-related parenchymal changes. They form in thyroid glands that are inflamed, autoimmune, or hormonally suppressed. Even when a nodule turns out to be cancer, the underlying thyroid environment matters for how aggressively the cancer behaves and how the rest of your thyroid will function long-term.
Optimizing your thyroid antibodies (TPO, thyroglobulin), free T3, free T4, and TSH can change the trajectory of nodule growth over time. Patients with positive TPO antibodies and elevated TSH have higher rates of nodule formation and growth than patients with quiet antibody status[7].
If you want to assess your underlying thyroid health, check your labs against optimal ranges with the Optimal Thyroid Lab Test Calculator, screen for autoimmune thyroiditis with the Hashimoto’s Symptom Quiz, or read the full guide to thyroid nodules on the blog.
Frequently Asked Questions
TR1 means your nodule scored zero points and is classified as Benign by ACR TI-RADS, with a malignancy risk under 1 percent. TR2 means your nodule scored 1 to 2 points and is classified as Not Suspicious, with a malignancy risk around 1.5 percent. Both TR1 and TR2 require no FNA biopsy and no follow-up imaging unless your doctor has a specific clinical concern that the calculator can’t capture (a strong family history of medullary thyroid cancer, for example, or a sudden change in nodule size between two ultrasounds)[1].
If you got a TR1 or TR2 result, the takeaway is that the nodule almost certainly is not cancer. The next step is to look at why the nodule formed in the first place. Most benign nodules form in thyroids with chronic inflammation, autoimmunity, or hormonal imbalance. Optimizing the underlying thyroid environment can prevent new nodules from forming and slow the growth of existing ones.
TR3 means your nodule scored exactly 3 points on ACR TI-RADS and is classified as Mildly Suspicious. The malignancy risk is around 4.8 percent, which is higher than baseline but still low[1]. ACR’s biopsy threshold for TR3 is 2.5 cm. If your nodule is smaller than 2.5 cm, you don’t need an immediate FNA biopsy. If it’s between 1.5 cm and 2.4 cm, ACR recommends follow-up ultrasound at 1, 3, and 5 years to monitor for growth or feature change. Below 1.5 cm, no routine surveillance is needed.
The roughly 5 percent cancer risk at TR3 is reassuring but not zero. About 95 out of 100 TR3 nodules turn out to be benign. The main reasons your doctor might recommend biopsy at a smaller TR3 size include personal or family history of thyroid cancer, history of head or neck radiation, abnormal cervical lymph nodes seen on the same scan, or rapid growth on serial imaging. Discuss those factors with your endocrinologist and don’t pressure for an FNA on a small TR3 unless one of those applies.
TR4 means your nodule scored 4 to 6 points on ACR TI-RADS and is classified as Moderately Suspicious. The malignancy risk is around 9.1 percent, which is significantly higher than baseline but still means about 90 out of 100 TR4 nodules turn out to be benign on biopsy[1]. ACR recommends FNA at 1.5 cm or larger and follow-up ultrasound at 1.0 to 1.4 cm at 1, 2, 3, and 5 years.
If your TR4 nodule is below 1.5 cm, the standard ACR recommendation is surveillance, not biopsy. The ATA system disagrees here for hypoechoic solid nodules, which it would classify as Intermediate Suspicion and recommend FNA at 1.0 cm. This is one of the most common ACR/ATA divergence cases. If you got a TR4 between 1.0 and 1.5 cm, run the same features through the calculator and look at the ATA panel. If ATA says Intermediate or High Suspicion, that’s worth discussing with your endocrinologist before defaulting to surveillance only.
Should you be worried? A TR4 deserves attention but not panic. The 90 percent benign rate is reassuring. The 10 percent cancer rate is the reason FNA exists for this category. Make the appointment, get the answer, then decide what to do with it.
TR5 means your nodule scored 7 or more points on ACR TI-RADS and is classified as Highly Suspicious. The malignancy risk is around 35 percent, which means about 1 in 3 TR5 nodules turn out to be cancer on biopsy[1]. ACR recommends FNA at 1.0 cm or larger and annual follow-up ultrasound for 5 years at 0.5 to 0.9 cm. The ATA system would classify the same nodule as High Suspicion with similar recommendations.
Is it cancer? Probably not, but the odds are high enough that biopsy is the only way to know. Two out of every three TR5 nodules turn out to be benign on FNA. The remaining one out of three is most often papillary thyroid carcinoma, which is the most common and most treatable form of thyroid cancer. Five-year survival for localized papillary thyroid cancer is near 100 percent[8]. A TR5 result is scary to read, but the path forward is clear: get the FNA, get the answer, then make a plan with your endocrinologist or surgeon.
If your TR5 nodule is between 0.5 and 1.0 cm (subcentimeter), you’re in the surveillance window where FNA is not the default. Discuss whether your radiologist or endocrinologist thinks the size threshold should be lowered based on lymph node findings, family history, or other risk factors.
The size threshold for biopsy depends entirely on the suspicion level. Both ACR TI-RADS and ATA use sliding size thresholds: the more suspicious the ultrasound features, the smaller the nodule needs to be to warrant biopsy. ACR’s thresholds are 2.5 cm for TR3, 1.5 cm for TR4, and 1.0 cm for TR5[1]. ATA’s thresholds are 2.0 cm for Very Low Suspicion, 1.5 cm for Low Suspicion, 1.0 cm for Intermediate or High Suspicion (sometimes 0.5 cm for High with concerning features)[2].
The reason for sliding thresholds is that benign nodules are extremely common (most adults have at least one) and biopsying every small nodule would cause more harm than good. Subcentimeter nodules (under 1.0 cm) generally don’t need biopsy unless they have highly suspicious features and are close to important structures like the trachea or recurrent laryngeal nerve. Nodules between 1.0 and 1.5 cm are the most controversial range, which is exactly where the two systems most often disagree.
ACR TI-RADS uses a point-based scoring system. Each ultrasound feature (composition, echogenicity, shape, margin, echogenic foci) gets a point value, the points get summed, and the total maps to a TR1 through TR5 level. ATA Sonographic Pattern uses a categorical decision tree. The pattern (Benign, Very Low, Low, Intermediate, or High Suspicion) is determined by the combination of composition, echogenicity, and presence or absence of suspicious features[1][2].
In US clinical practice, ACR TI-RADS is the system most radiologists use on their reports, which is why your ultrasound report shows a TR score. ATA is more commonly referenced by endocrinologists and is the system used in most international guidelines. The two systems were developed independently and validated on different patient populations. They overlap heavily but disagree often enough that it’s worth running both, which is what this calculator does.
ACR and ATA disagree on roughly 20 to 30 percent of nodules[3][6]. The most common pattern is that one system recommends FNA biopsy at the current nodule size while the other recommends follow-up imaging only. When this happens, the disagreement is itself useful information. It tells you that your nodule sits in a borderline zone where reasonable clinicians using validated systems would make different choices.
The right move is to bring both results to your endocrinologist or radiologist and have an explicit conversation about which path makes more sense for your specific situation. Factors that push toward biopsy include personal or family history of thyroid cancer, history of head or neck radiation, abnormal cervical lymph nodes seen on the same scan, demonstrated growth on serial imaging, your own preference for definitive answers over surveillance, and your access to high-quality FNA. Factors that push toward surveillance include none of the above, plus a stable nodule size on prior imaging, advanced age (where slow-growing thyroid cancers may not affect lifespan), and high-risk anesthesia profile if biopsy or surgery would be complicated.
Yes, often. About 90 out of 100 TR4 nodules turn out to be benign on biopsy. About 65 out of 100 TR5 nodules turn out to be benign on biopsy[1]. The TR scoring system is designed to identify which nodules deserve a biopsy, not to predict which nodules are cancer. A high TR score raises the pre-test probability of malignancy enough to justify the small risk and cost of FNA, but most positive ultrasound findings are still benign on histology.
The most common benign findings that get scored as TR4 or TR5 are colloid nodules with cystic degeneration, follicular adenomas, Hashimoto’s-related parenchymal changes, and benign hyperplastic nodules with calcifications. None of these are cancer. The reason they score high on TI-RADS is that some of their ultrasound features (microcalcifications in colloid nodules, hypoechoic appearance in follicular adenomas, irregular margins in Hashimoto’s pseudonodules) overlap with the features cancer also produces.
Your FNA biopsy results will be reported using the Bethesda System for Reporting Thyroid Cytopathology, which classifies the result into one of six categories from Bethesda I (non-diagnostic, sample inadequate) through Bethesda VI (malignant, definitively cancer). Each Bethesda category carries a different malignancy risk and a different recommended next step[9].
Bethesda II is benign and requires only routine surveillance. Bethesda III (atypia of undetermined significance) and Bethesda IV (suspicious for follicular neoplasm) often require repeat FNA, molecular testing, or diagnostic surgery to determine whether the nodule is cancer. Bethesda V (suspicious for malignancy) and Bethesda VI (malignant) usually proceed to thyroid surgery. The Bethesda Calculator (coming soon to this site) will help you decode your specific Bethesda category and walk through the next steps.
References
- Tessler FN, Middleton WD, Grant EG, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS): White Paper of the ACR TI-RADS Committee. Journal of the American College of Radiology. 2017;14(5):587-595. https://www.jacr.org/article/S1546-1440(17)30186-1/fulltext
- Haugen BR, Alexander EK, Bible KC, et al. 2015 American Thyroid Association Management Guidelines for Adult Patients with Thyroid Nodules and Differentiated Thyroid Cancer. Thyroid. 2016;26(1):1-133. https://www.liebertpub.com/doi/10.1089/thy.2015.0020
- Castellana M, Castellana C, Treglia G, et al. Performance of Five Ultrasound Risk Stratification Systems in Selecting Thyroid Nodules for FNA. Journal of Clinical Endocrinology & Metabolism. 2020;105(5):1659-1669. https://academic.oup.com/jcem/article/105/5/1659/5717687
- Moon WJ, Jung SL, Lee JH, et al. Benign and malignant thyroid nodules: US differentiation–multicenter retrospective study. Radiology. 2008;247(3):762-770. https://pubs.rsna.org/doi/10.1148/radiol.2473070944
- Cappelli C, Castellano M, Pirola I, et al. The predictive value of ultrasound findings in the management of thyroid nodules. QJM: An International Journal of Medicine. 2007;100(1):29-35. https://academic.oup.com/qjmed/article/100/1/29/1531506
- Yim Y, Na DG, Ha EJ, et al. Concordance of Three International Guidelines for Thyroid Nodules Classified by Ultrasonography and Diagnostic Performance of Biopsy Criteria. Korean Journal of Radiology. 2020;21(1):108-116. https://www.kjronline.org/DOIx.php?id=10.3348/kjr.2019.0215
- Anil C, Akkurt A, Ayturk S, Kut A, Gursoy A. Hashimoto’s thyroiditis is not associated with increased risk of thyroid cancer in patients with thyroid nodules: a single-center prospective study. Thyroid. 2010;20(6):601-606. https://www.liebertpub.com/doi/10.1089/thy.2009.0450
- SEER Cancer Statistics Review (CSR), Thyroid Cancer 5-Year Relative Survival. National Cancer Institute. https://seer.cancer.gov/statfacts/html/thyro.html
- Cibas ES, Ali SZ. The 2017 Bethesda System for Reporting Thyroid Cytopathology. Thyroid. 2017;27(11):1341-1346. https://www.liebertpub.com/doi/10.1089/thy.2017.0500