The short answer
In ACR TI-RADS, TR4 covers any nodule scoring 4 to 6 points. The recommendation then turns on size: needle biopsy at 1.5 cm or more, follow-up scans from 1.0 to 1.4 cm, and neither below that.
TR4 is a range of point totals, so two TR4 nodules can look quite different on the scan.
At TR4 the size threshold does the work: 1.5 cm and above is sent for fine-needle aspiration, 1.0 to 1.4 cm is watched, under 1.0 cm gets neither.
Watching a TR4 nodule has a set schedule: repeat ultrasound at 1, 2, 3 and 5 years.
Choose how you want to understand this
The full explanation.
TR4 is a band, not a single look
ACR TI-RADS scores five ultrasound features and adds the points up. The total, not the appearance, sets the level.
The levels are narrow at the bottom and wide in the middle. TR1 is 0 points. TR2 is 2 points. TR3 is 3 points. TR5 is 7 points or more.
TR4 is everything from 4 to 6 points. That is the widest band on the chart, which is why two TR4 nodules can read very differently in the description.
How a nodule lands between 4 and 6 points
The points come from composition, echogenicity, shape, margin, and echogenic foci. Adding them shows how easily a nodule reaches the TR4 band:
- solid (2) and hypoechoic (2), with smooth margins and no bright specks, totals 4 points
- mixed cystic and solid (1), hypoechoic (2), with a lobulated or irregular margin (2), totals 5 points
- solid (2), very hypoechoic (3), with macrocalcifications (1), totals 6 points
Add tiny punctate echogenic foci, worth 3 points, to that first example and the total reaches 7. The nodule becomes TR5.
So the gap between TR4 and TR5 can be a single feature. It is worth reading which features your report listed.
At TR4, size decides the recommendation
This is the part people miss. The level alone does not produce a plan. ACR pairs each level with size thresholds, and at TR4 they are:
| Largest measurement | ACR TI-RADS recommendation |
|---|---|
| 1.5 cm or more | Fine-needle aspiration |
| 1.0 to 1.4 cm | Follow-up ultrasound |
| Under 1.0 cm | No aspiration and no follow-up |
That is why a friend with the same TR4 label may have been biopsied when you were not. The chart treated the two nodules differently because of a few millimeters.
The follow-up schedule is specific
If a TR4 nodule falls in the 1.0 to 1.4 cm window, the ACR reporting template sets out when to look again: repeat ultrasound at 1, 2, 3 and 5 years.
Compare that with the neighboring levels. TR3 nodules being watched are scanned at 1, 3 and 5 years. TR5 nodules being watched are scanned every year for 5 years.
The schedule tightens as the level rises. If your report gives a level but no interval, that is a fair thing to ask about.
What counts as a real change
Thyroid nodules are measured by hand, so small differences between scans are common and often mean nothing.
The ACR template sets a bar for what counts. A significant change in size is an increase of at least 20% in two dimensions, with a minimum increase of 2 mm.
The template also asks the radiologist to record whether the features changed, and whether the TI-RADS category itself changed. Those two lines can matter more than the millimeters.
What a TR4 cannot tell you
A TI-RADS level is a radiologist's structured estimate of risk from an image. It is not a diagnosis, and no ultrasound can grade a nodule.
If aspiration is done, the cells are reported using a different system: the Bethesda System for Reporting Thyroid Cytopathology, whose third edition arrived in 2023 with six named categories.
One footnote on the ACR chart does carry extra weight. A nodule with definite spread outside the thyroid should be treated as malignant until proven otherwise, whatever the point total.
Questions for the doctor who ordered the scan
- What was the point total, and which features contributed?
- What is the largest dimension?
- Does my size fall above or below the aspiration threshold?
- Is there an older scan to compare with?
- If we watch it, when is the next ultrasound and who books it?
Related reading
The scoring system as a whole is explained in What Does TI-RADS Mean on a Thyroid Ultrasound. See also Thyroid Nodule on Ultrasound: What Now and What Does Bethesda Category Mean on a Thyroid Biopsy.
Sources
Words to know
Tap any term to see what it means.
Common questions
Is TI-RADS 4 the fourth stage of thyroid cancer?
No. TI-RADS levels are not cancer stages. TR4 simply means the ultrasound features added up to between 4 and 6 points on the ACR chart, before anyone knows what the nodule is.
Why was my 1.2 cm TR4 nodule not biopsied?
The ACR chart recommends fine-needle aspiration for TR4 nodules at 1.5 cm or larger. Between 1.0 and 1.4 cm it recommends follow-up ultrasound instead, at 1, 2, 3 and 5 years.
What counts as the nodule growing?
The ACR reporting template treats a significant size change as an increase of at least 20% in two dimensions, with a minimum increase of 2 mm.
Questions to ask your doctor
Being prepared helps you get the most out of your appointments. Save or print these questions.
Tap a question to save it to your list (kept on this device).
Your next step
Turn this topic into questions for your next appointment.
Speak With Trained Specialists & Human Navigators
Cancer Explained provides educational guidance, but does not replace trained specialists, social workers, or your medical team.
Talk to a trained cancer information specialist
Free, confidential assistance from NCI Cancer Information Service via phone, chat, or email.
Contact your oncology team
Locate after-hours contact numbers, portal messages, or urgent triage phone lines.
Find a patient navigator
Get one-on-one help with appointments, logistics, translation, and care coordination.
Find a genetic counselor
Discuss inherited mutation risk, family history, and genetic testing options.
Find an oncology social worker
Access emotional counseling, family support groups, and mental health resources.
Find a financial navigator
Locate copay assistance foundations, grant programs, and lodging/travel support.
Find a clinical-trial specialist
Search matching studies and speak with NCI trial information specialists.
Get urgent help
Immediate emergency guidance for fever (>100.4°F during chemo), severe pain, or shortness of breath.
Help Us Improve This Guide
Did this explanation answer your question and help you determine your next step?
Know someone who needs this?
Plenty of people are looking for something like this and do not know where to start. If this would help a friend or someone you love, send it on — we have written an opening line so you do not have to stare at an empty message. You can change every word of it.
Your message is written and sent in your own email or messaging app — we never see who you send it to, and nothing is added to any list.
Plain-language explanation of the published sources cited on this page. AI-assisted, source-checked, not clinician-reviewed.
Sources last checked: 2026-07-21 what this meansLast updated: 2026-08-10Next planned review: 2027-07-21
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status — Source checked. This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
General education — varies by person. Answers genuinely differ between people. This page explains what commonly varies and points you to your care team for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
How this page was created
Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes. We do not employ clinicians and do not intend to — our work is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and checked line by line against the sources listed on it. That confirms the sources support what the page says. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
Read more about our editorial process, our use of AI, and our corrections policy.
Spotted a problem? Report an error — a factual mistake, broken or outdated source, confusing wording, or anything that seems unsafe. Please do not include names, medical record numbers, dates of birth, addresses, or other identifying medical information in your report.
After using this page, do you understand what to do next?
Anonymous — we only record the answer, never who gave it.
Related articles
Still have questions?
Educational answers, plain language
Free to print and share