Thyroid Nodule Tools — Dr. Ted Michelakos

ACR TI-RADS Calculator

Composition

Select one

Echogenicity

Select one

Shape

Select one

Margin

Select one

Echogenic Foci

Select all that apply — points are cumulative

Largest Dimension

Maximum nodule diameter — used to determine FNA and follow-up thresholds

Size (cm)

Points

TI-RADS TR1

ACR TI-RADS Category

—

points

Recommended Action

—

Malignancy Risk

—

Parameter	Value

Based on ACR TI-RADS: Tessler et al., J Am Coll Radiol 2017. This calculator is intended as a clinical reference tool and does not replace physician judgment. Management decisions should be individualized based on clinical context, patient risk factors, and shared decision-making.

TI-RADS Reference

← scroll →

Category	Points	Description	Malignancy Risk	FNA Threshold	Follow-up
TR1	0	Benign	< 0.3%	No FNA	No follow-up
TR2	2	Not suspicious	< 1.5%	No FNA	No follow-up
TR3	3	Mildly suspicious	~5%	≥ 2.5 cm	≥ 1.5 cm
TR4	4–6	Moderately suspicious	5–20%	≥ 1.5 cm	≥ 1.0 cm
TR5	≥ 7	Highly suspicious	> 20%	≥ 1.0 cm	≥ 0.5 cm

Nodule Volume & Change Over Time

Calculator

Thyroid Nodule Volume

ATA half-cube formula: V = 0.5 × d1 × d2 × d3 (cm³). A ≥ 50% volume increase flags as significant growth.

Measurement	Date	d1 (cm)	d2 (cm)	d3 (cm)	Vol (cm³)	Δ baseline	Δ prior

Based on the ATA half-cube formula. Not a substitute for clinical judgment. ATA calculator ↗