TI-RADS Calculator

What is this?

A TI-RADS Calculator applies the American College of Radiology Thyroid Imaging Reporting and Data System to a thyroid nodule seen on ultrasound. Five sonographic features are scored and added to place the nodule in a category from TR1 (benign) through TR5 (highly suspicious), each with an estimated malignancy risk.

How to Use the TI-RADS Calculator

The TI-RADS Calculator applies the American College of Radiology Thyroid Imaging Reporting and Data System to a thyroid nodule seen on ultrasound. Five sonographic features are scored, the points are added, and the total places the nodule in a category from TR1 (benign) to TR5 (highly suspicious).

The category alone does not decide management. Combined with the nodule's largest dimension it gives the ACR recommendation: fine-needle aspiration, ultrasound surveillance, or neither.

1. Score the Composition

Choose what the nodule is made of - cystic, spongiform, mixed cystic and solid, solid, or indeterminate because of calcification. Spongiform means predominantly (over 50%) small cystic spaces.

2. Score the Echogenicity

Compare the nodule's reflectivity to the surrounding thyroid. Very hypoechoic means darker than the adjacent strap muscles, not merely darker than thyroid tissue - a common source of under-scoring. This category is skipped automatically for spongiform nodules.

3. Score the Shape and Margin

Judge taller-than-wide on the transverse (axial) plane, not the sagittal. Then choose the margin: smooth, ill-defined, lobulated or irregular, or extra-thyroidal extension.

4. Select Every Echogenic Focus Present

This category is additive, so select all that apply. A nodule with both macrocalcifications and punctate echogenic foci scores 1 + 3 = 4 points from this category alone.

5. Enter the Nodule Size

Enter the largest dimension in centimetres or millimetres. The calculator then reports whether the nodule meets the FNA threshold for its TR level, falls in the surveillance band, or needs neither.

Key Formulas Used in the Calculator

Total TI-RADS Points

$\text{Points} = \text{Composition} + \text{Echogenicity} + \text{Shape} + \text{Margin} + \sum \text{Echogenic Foci}$

The first four categories each contribute a single score. Echogenic foci is the only additive category - every type present adds its points.

Points to TR Level

$\text{TR Category} = \begin{cases} \mathrm{TR1}, & 0\text{--}1\ \text{points} \\[4pt] \mathrm{TR2}, & 2\ \text{points} \\[4pt] \mathrm{TR3}, & 3\ \text{points} \\[4pt] \mathrm{TR4}, & 4\text{--}6\ \text{points} \\[4pt] \mathrm{TR5}, & 7+\ \text{points} \end{cases}$

Note that TR1 covers both 0 and 1 point. A nodule scoring a single point - for example a mixed cystic and solid nodule with no other suspicious feature - is still TR1.

FNA Thresholds by Level

TR3 at 2.5 cm or more, TR4 at 1.5 cm or more, TR5 at 1 cm or more

TR1 and TR2 need no biopsy at any size. Below the FNA threshold, TR3 nodules from 1.5 cm, TR4 from 1 cm and TR5 from 0.5 cm enter ultrasound surveillance instead.

Example

$\text{Solid }(2) + \text{Very Hypoechoic }(3) + \text{Taller Than Wide }(3) + \text{Lobulated }(2) + \text{Punctate Foci }(3) = 13\ \text{points} = \mathrm{TR5}$

Thirteen points is well past the 7-point TR5 threshold. If this nodule is 1 cm or larger, FNA is recommended; between 0.5 and 0.9 cm it is followed annually for five years.

Benefits

• Implements the 2017 ACR TI-RADS white paper scoring exactly

• Handles the additive echogenic foci category correctly

• Skips echogenicity for spongiform nodules as the ACR chart specifies

• Turns the TR level plus nodule size into an actual FNA or follow-up recommendation

• Shows a per-category points breakdown, not just a total

• Highlights your level in the full TR1 to TR5 reference table

• Accepts nodule size in centimetres or millimetres

When & Where to Use

• Structuring a thyroid ultrasound report

• Deciding whether a nodule meets the FNA size threshold

• Teaching TI-RADS scoring to radiology trainees

• Double-checking a category assignment before reporting

• Explaining to a patient why a nodule is being watched rather than biopsied

• Auditing thyroid nodule management against ACR guidance

• Comparing risk between two nodules in the same gland

Who Should Use This Calculator

The TI-RADS Calculator is intended for radiologists, sonographers, endocrinologists, surgeons and medical trainees who report or act on thyroid ultrasound. It is a decision support tool used alongside the full clinical picture, not a diagnostic test.

Tips to Get the Best Deal

Very hypoechoic is judged against the strap muscles, not the thyroid

Assess taller-than-wide on the transverse plane, never the sagittal

Echogenic foci add up - do not select only the highest-scoring one

Large comet-tail artifacts score 0 and suggest benign colloid

Punctate echogenic foci are the highest-scoring focus at 3 points

A TR5 nodule under 1 cm is followed, not biopsied

Score each nodule separately when the gland contains several

Pro Tips

• Very hypoechoic is judged against the strap muscles, not the thyroid parenchyma.

• Assess taller-than-wide on the transverse plane, not the sagittal.

• Echogenic foci points add together - select every type present.

• TR1 covers both 0 and 1 point; TR2 is exactly 2 points.

• A TR5 nodule under 1 cm is followed with ultrasound, not biopsied.

• This is decision support for clinicians and does not replace radiologist judgement.