About the ACR TI-RADS score
The American College of Radiology Thyroid Imaging Reporting and Data System (ACR TI-RADS), published by Tessler and colleagues in 2017, is a point-based scheme for describing a thyroid nodule on ultrasound. It scores five feature categories, sums the points, and sorts the nodule into one of five risk categories, TR1 through TR5. Those categories, combined with the nodule's largest diameter, generate a standardized recommendation for whether fine-needle aspiration (FNA) biopsy or follow-up ultrasound is appropriate.
How the score is built
- Composition: cystic or almost completely cystic and spongiform score 0 points; mixed cystic and solid scores 1 point; solid or almost completely solid, and nodules where composition cannot be determined, score 2 points.
- Echogenicity: anechoic scores 0 points; hyperechoic or isoechoic scores 1 point; hypoechoic scores 2 points; very hypoechoic scores 3 points; indeterminate echogenicity scores 1 point.
- Shape: wider-than-tall scores 0 points; taller-than-wide scores 3 points.
- Margin: smooth or ill-defined scores 0 points; lobulated or irregular scores 2 points; extra-thyroidal extension scores 3 points.
- Echogenic foci: none, or large comet-tail artifacts, score 0 points. Macrocalcifications add 1 point, peripheral (rim) calcifications add 2 points, and punctate echogenic foci add 3 points — these add together if more than one type is present in the same nodule.
Adding the five subtotals gives the total TI-RADS points, which map to a category: 0 points is TR1, 2 points is TR2, 3 points is TR3, 4 to 6 points is TR4, and 7 or more points is TR5.
Interpreting the result
TR1 (benign) and TR2 (not suspicious) nodules are not biopsied regardless of size. TR3 (mildly suspicious) nodules are biopsied at 2.5 cm and followed at 1.5 cm. TR4 (moderately suspicious) nodules are biopsied at 1.5 cm and followed at 1 cm. TR5 (highly suspicious) nodules are biopsied at 1 cm and followed at 0.5 cm. Smaller nodules below the follow-up threshold generally need no immediate action.
When to consult a professional
This tool performs the standard ACR TI-RADS arithmetic for education and record-keeping only — it does not read an ultrasound image and is not a diagnosis. The underlying feature ratings (composition, echogenicity, shape, margin, echogenic foci) must be assigned by a radiologist reading the actual images. Any decision about biopsy or follow-up should be made with your radiologist or endocrinologist, who can weigh the images and your full clinical picture.