What is the ACR TI-RADS Calculator?

The ACR TI-RADS Calculator (American College of Radiology Thyroid Imaging, Reporting and Data System) is a clinical risk-stratification system designed to evaluate thyroid nodules on ultrasound. Developed in 2017 by the ACR TI-RADS Committee, this scoring framework assists radiologists, endocrinologists, and clinicians in determining malignancy probability and standardizing decisions for Fine Needle Aspiration (FNA) biopsy or ultrasound surveillance.

By assigning standardized numerical points across five sonographic feature categories, the system balances cancer detection against the risks of unnecessary biopsies on benign nodules. You can also evaluate other clinical indicators using our tPA Dosage Calculator and TIMI NSTEMI Score Calculator.

How ACR TI-RADS Scoring Works

Ultrasound findings are evaluated across five distinct categories. Points from each category are summed to establish the overall TI-RADS level:

Category	Sonographic Feature	Points
Composition (choose 1)	Cystic or almost completely cystic	0
	Spongiform (>50% microcystic)	0
	Mixed cystic and solid	1
	Solid or almost completely solid	2
Echogenicity (choose 1)	Anechoic (cystic)	0
	Hyperechoic or Isoechoic compared to thyroid parenchyma	1
	Hypoechoic compared to thyroid parenchyma	2
	Very hypoechoic (darker than strap muscles)	3
Shape (choose 1)	Wider-than-tall	0
Shape (choose 1)	Taller-than-wide (measured in transverse or sagittal plane)	3
Margin (choose 1)	Smooth	0
	Ill-defined	0
	Lobulated or Irregular	2
	Extra-thyroidal extension (invading adjacent tissue)	3
Echogenic Foci (select all that apply)	None or Large comet-tail artifacts	0
	Macrocalcifications (with acoustic shadowing)	1
	Peripheral (rim) calcifications	2
	Punctate echogenic foci (microcalcifications)	3

ACR TI-RADS Risk Categories and Management Thresholds

Based on the total point score, the thyroid nodule is categorized from TR1 (benign) to TR5 (highly suspicious). Size cutoffs dictate whether Fine Needle Aspiration (FNA) biopsy or serial ultrasound follow-up is recommended:

TR1 (0 points): Benign. Risk of malignancy < 2%. No FNA or ultrasound follow-up required.
TR2 (2 points): Not Suspicious. Risk of malignancy < 2%. No FNA or ultrasound follow-up required.
TR3 (3 points): Mildly Suspicious. Risk of malignancy ~5%. FNA recommended if size ≥ 2.5 cm; follow-up ultrasound at 1, 3, and 5 years if size ≥ 1.5 cm.
TR4 (4 to 6 points): Moderately Suspicious. Risk of malignancy 5% to 20%. FNA recommended if size ≥ 1.5 cm; follow-up ultrasound at 1, 2, 3, and 5 years if size ≥ 1.0 cm.
TR5 (≥ 7 points): Highly Suspicious. Risk of malignancy > 20%. FNA recommended if size ≥ 1.0 cm; annual follow-up ultrasound for up to 5 years if size ≥ 0.5 cm.

Frequently Asked Questions

Why was ACR TI-RADS created?

Thyroid nodules are extremely common on high-resolution imaging, but the vast majority are benign. ACR TI-RADS standardizes terminology and introduces conservative size thresholds to substantially reduce unnecessary benign biopsies while preserving high sensitivity for clinically significant thyroid cancers.

Can multiple echogenic foci points be combined?

Yes. Unlike the first four categories where only one feature is selected, echogenic foci points are additive. If a nodule exhibits both macrocalcifications (1 point) and punctate microcalcifications (3 points), 4 total points are added for echogenic foci.

What does "taller-than-wide" mean?

A nodule is considered taller-than-wide when its anteroposterior diameter exceeds its transverse diameter on either transverse or longitudinal ultrasound views. This feature reflects centrifugal growth across tissue planes and is a strong predictor of malignancy (3 points).

What should be done if a nodule does not meet biopsy size criteria?

If the nodule meets the follow-up threshold, periodic ultrasound monitoring is recommended to evaluate for interval growth (defined as a 20% increase in at least two dimensions with a minimum 2 mm increase, or a 50% increase in volume). If no growth occurs over the surveillance period, follow-up can be safely discontinued.

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