A TI-RADS 4 result, also written TR4, means your thyroid nodule is moderately suspicious on ultrasound. It is one of the more common categories people ask about, and it sits between the mild concern of TR3 and the high suspicion of TR5. This guide explains what a TR4 nodule means, its cancer risk, and when a biopsy is recommended.
What TR4 means
The ACR TI-RADS system scores five ultrasound features and adds the points. A nodule that totals 4 to 6 points is classified as TR4, described as moderately suspicious. The score usually reflects a combination of concerning features, such as a solid composition together with a hypoechoic appearance or an irregular margin.
A TR4 category tells your doctor the nodule has enough suspicious features to warrant attention, but it does not mean the nodule is cancer.
TR4 malignancy risk
The estimated risk that a TR4 nodule is malignant is around 9.1 percent. In other words, roughly nine out of ten TR4 nodules turn out to be benign. The category exists to make sure the small share that are cancer are caught, without biopsying every nodule.
Here is how TR4 compares with the neighboring categories:
| Category | Points | Suspicion | Est. malignancy |
|---|---|---|---|
| TR3 | 3 | Mild | ~4.8% |
| TR4 | 4–6 | Moderate | ~9.1% |
| TR5 | 7+ | High | ~35% |
See the full breakdown in our TI-RADS score guide.
When a TR4 nodule needs a biopsy
For TR4, the decision to biopsy depends on the nodule’s size:
- 1.5 cm or larger — fine needle aspiration (FNA) biopsy is recommended.
- 1.0 to 1.4 cm — follow-up ultrasound is recommended at 1, 2, 3, and 5 years.
- Under 1.0 cm — usually no biopsy and no routine follow-up.
Size does not change the TR4 category, but it decides what happens next. The TI-RADS calculator applies your nodule’s size automatically and shows the exact recommendation.
For clinicians: TR4 spans a wide 4–6 point range, so document the contributing features. A 4-point nodule behaves very differently from a 6-point nodule at the margins of the category, and serial growth should lower your threshold for FNA.
What a fine needle aspiration involves
If a biopsy is advised, FNA is a quick procedure done under ultrasound guidance. A thin needle samples cells from the nodule, which are examined for cancer. It is usually done in the clinic and takes only a few minutes. Results guide whether monitoring, surgery, or further testing is needed.
TR4 vs TR3 and TR5
If your nodule scored only 3 points it would be TR3, mildly suspicious, with a lower biopsy threshold based on a larger size. If it reached 7 or more points it would be TR5, highly suspicious, with biopsy considered at 1 cm. Knowing the exact points helps you understand where your nodule falls.
Frequently asked questions
Is a TI-RADS 4 nodule cancer?
Usually not. The estimated malignancy risk for TR4 is about 9 percent, so most are benign. A biopsy is how doctors confirm.
What size TR4 nodule needs a biopsy?
Biopsy is generally recommended for TR4 nodules that are 1.5 cm or larger. Nodules from 1 to 1.4 cm are followed with ultrasound, and smaller ones need no action.
Can a TR4 nodule become TR5?
A nodule’s category can change if its ultrasound features change over time. That is why follow-up scans are recommended for nodules that are watched rather than biopsied.