If your thyroid ultrasound report says TR4, you are looking at a moderately suspicious result in the ACR TI-RADS scoring system. This guide explains what TR4 means in plain language, what the cancer risk actually is, and what usually happens next.

TR4 in Plain English

TR4 stands for TI-RADS category 4. It means your thyroid nodule scored between 4 and 6 points when a radiologist evaluated five ultrasound features: composition, echogenicity, shape, margin, and echogenic foci. A score in this range places it in the “moderately suspicious” category.

Moderately suspicious does not mean you have cancer. It means the nodule has enough features associated with malignancy that your doctor needs to take a closer look, usually based on the nodule’s size.

What Is the Cancer Risk for TR4?

The estimated malignancy risk for a TR4 nodule is approximately 9.1 percent. That means about 9 out of 100 TR4 nodules are cancer and roughly 91 out of 100 are benign. The category exists to make sure the small share that are malignant get caught without biopsying every single nodule.

Does TR4 Mean I Need a Biopsy?

It depends on the nodule’s size. For TR4, the ACR recommends:

  • 1.5 cm or larger — fine needle aspiration biopsy is recommended
  • 1.0 to 1.4 cm — follow-up ultrasound at 1, 2, 3, and 5 years
  • Under 1.0 cm — no biopsy and no routine follow-up

So a TR4 nodule measuring 0.8 cm needs nothing, while the same TR4 at 1.6 cm should be biopsied. Size is what tips the decision. Check your specific situation with the TI-RADS calculator.

What Features Cause a TR4 Score?

Common combinations that land in the 4-to-6 point range include a solid nodule (2 points) that is also hypoechoic (2 points) with smooth margins and no calcifications, totaling 4 points. Or a solid isoechoic nodule with an irregular margin (2 points), reaching 5. The specific features vary, but the total is what determines the category.

You can see every feature and its point value on the TI-RADS chart.

What to Ask Your Doctor

Bring these three questions to your appointment: what is my nodule’s exact size in centimeters, does the size meet the threshold for biopsy at TR4, and if not, when is my follow-up ultrasound scheduled? These are the questions that turn an anxiety-producing report into a clear action plan.

For the full TR4 breakdown, see our detailed TI-RADS 4 guide.

Frequently Asked Questions

Is TR4 serious?
TR4 is moderately suspicious with about a 9 percent cancer risk. Most TR4 nodules are benign. Whether it needs action depends on size, not the category alone.

What is the difference between TR4 and TR5?
TR4 scores 4 to 6 points with ~9% malignancy risk and a biopsy threshold of 1.5 cm. TR5 scores 7 or more with ~35% risk and a biopsy threshold of 1.0 cm.

Can TR4 change to TR3 or TR5?
A nodule’s category can change if its ultrasound features change on a follow-up scan. This is why serial monitoring is recommended for smaller nodules.