The ACR TI-RADS system scores five ultrasound features to assess thyroid nodule risk. This page explains what each feature looks like on ultrasound, how to identify it, and how many points it earns. Use this as a visual reference alongside the TI-RADS calculator and the scoring chart.
1. Composition — What Is the Nodule Made Of?
Composition describes the internal structure of the nodule — whether it is filled with fluid, solid tissue, or a mix of both.
Cystic or Almost Completely Cystic (0 points)
The nodule appears entirely black (fluid-filled) on ultrasound with no solid component. Simple cysts are almost always benign. They often have thin, smooth walls and may show posterior acoustic enhancement behind them.
Spongiform (0 points)
A spongiform nodule contains multiple small cystic spaces that give it a sponge-like or honeycomb appearance. More than 50 percent of the nodule is made up of these tiny fluid pockets. This pattern is characteristic of benign colloid nodules and scores 0 points.
Mixed Cystic and Solid (1 point)
The nodule has both fluid and solid components. The solid portion may appear along one wall or as an irregular mass within the cyst. The more solid tissue present, the more attention it gets.
Solid or Almost Completely Solid (2 points)
The nodule is made entirely or almost entirely of solid tissue. This is the most common composition for both benign and malignant nodules, which is why it earns 2 points — not because it is likely cancer, but because solid nodules need the other features to determine risk.
2. Echogenicity — How Bright or Dark Is It?
Echogenicity compares the nodule brightness to surrounding normal thyroid tissue. Darker nodules score higher because thyroid cancers tend to be darker. For a deep dive, see our hypoechoic thyroid nodule guide.
Anechoic (0 points)
Completely black with no internal echoes. This is seen in simple cysts and the fluid components of mixed nodules. Anechoic structures carry virtually no cancer risk from this feature alone.
Hyperechoic or Isoechoic (1 point)
Hyperechoic means brighter than normal thyroid tissue, and isoechoic means the same brightness. Both score just 1 point. Most hyperechoic nodules are benign.
Hypoechoic (2 points)
Darker than the surrounding thyroid tissue but not as dark as the neck muscles. This is the echogenicity most commonly associated with thyroid malignancy, scoring 2 points. However, many benign nodules are also hypoechoic.
Very Hypoechoic (3 points)
Darker than the strap muscles of the neck. This is the most concerning echogenicity and earns the highest score in this category. Very hypoechoic nodules have the strongest association with papillary thyroid carcinoma.
3. Shape — Wider or Taller?
Shape is assessed on a transverse ultrasound image by comparing the nodule height to its width.
Wider-Than-Tall (0 points)
Most thyroid nodules grow along tissue planes and appear wider than tall. This is the normal growth pattern and scores 0 points.
Taller-Than-Wide (3 points)
A nodule that grows taller than wide is growing against tissue planes, a pattern more frequently seen in malignancy. This single feature earns 3 points and is one of the most specific indicators of potential cancer in TI-RADS.
4. Margin — What Do the Edges Look Like?
Smooth (0 points)
The nodule has a clean, well-defined, even border. Smooth margins are typical of benign nodules.
Ill-Defined (0 points)
The border is difficult to trace precisely — hazy rather than sharp, but not truly irregular. Scores 0 points.
Lobulated or Irregular (2 points)
The border has spiculations, jagged edges, or angular projections. Lobulated margins show rounded protrusions. Both patterns earn 2 points.
Extra-Thyroidal Extension (3 points)
The nodule extends beyond the thyroid capsule into surrounding structures. This is a sign of aggressive growth and earns the highest margin score.
5. Echogenic Foci — Bright Spots Inside the Nodule
Echogenic foci are bright spots within or around the nodule. Unlike other categories, here you select all features present and add the points together.
None or Large Comet-Tail Artifacts (0 points)
No bright spots, or the nodule shows large comet-tail artifacts (bright V-shaped lines trailing from colloid crystals). Comet tails longer than 1 mm are considered benign and score 0.
Macrocalcifications (1 point)
Large calcifications that produce acoustic shadowing. These coarse calcium deposits are seen in both benign and malignant nodules and earn 1 point.
Peripheral (Rim) Calcifications (2 points)
Calcification along the outer edge of the nodule, forming a partial or complete ring. Sometimes called eggshell calcification. Scores 2 points.
Punctate Echogenic Foci (3 points)
Tiny bright dots (typically smaller than 1 mm) scattered within the solid portion of a nodule, without acoustic shadowing. These represent microcalcifications and are strongly associated with papillary thyroid carcinoma, earning the highest score in this category.
Distinguish punctate echogenic foci from the posterior aspect of cystic spaces (which mimic bright dots) and from comet-tail artifacts (V-shaped, trailing more than 1 mm). True microcalcifications are non-shadowing, non-tailing, and located within the solid component.
Putting It All Together
After evaluating all five features, add the points and find the TI-RADS category on the TI-RADS chart. Or enter the features directly into the TI-RADS calculator to get the category, malignancy risk, and size-based recommendation automatically.
Example Scoring
| Feature | Finding | Points |
|---|---|---|
| Composition | Solid | 2 |
| Echogenicity | Hypoechoic | 2 |
| Shape | Wider-than-tall | 0 |
| Margin | Smooth | 0 |
| Echogenic foci | None | 0 |
| Total | 4 | |
Total = 4 points, which is TR4, moderately suspicious (~9.1% malignancy risk). If the nodule measures 1.8 cm, FNA biopsy is recommended. If it measures 1.2 cm, follow-up ultrasound is recommended instead. Read more in our TR4 guide.
For the complete ACR TI-RADS scoring system, see our ACR TI-RADS overview.