TI-RADS Calculator
Calculate the ACR TI-RADS score for thyroid nodule risk stratification using ultrasound composition, echogenicity, shape, margin, and echogenic foci with TR category and malignancy risk.
About This Calculator
The TI-RADS (Thyroid Imaging Reporting and Data System) calculator helps radiologists, endocrinologists, and healthcare professionals compute the ACR TI-RADS score for thyroid nodule risk stratification based on ultrasound findings. Developed by the American College of Radiology, this standardized system evaluates five key ultrasound features — composition, echogenicity, shape, margin, and echogenic foci — to determine the malignancy risk and guide decisions about fine needle aspiration (FNA).
The score is calculated by summing points from each category: composition (0-2 points), echogenicity (0-3 points), shape (0 or 3 points), margin (0, 2, or 3 points), and echogenic foci (0-3 points per feature, additive for multiple types). The total score ranges from 0 to 17 and maps to one of five TI-RADS categories (TR1-TR5), each with a corresponding malignancy risk ranging from 0.3% for TR1 to 35% for TR5 and specific FNA and follow-up thresholds.
Regional Notes
India: ACR TI-RADS is widely used in Indian radiology departments and thyroid clinics. FNA and follow-up recommendations follow the same ACR criteria. Thyroid nodules are common in India due to endemic iodine deficiency regions, making TI-RADS an essential triage tool.
United States: The ACR TI-RADS is the standard of care for thyroid nodule ultrasound reporting. The ACR recommends using TI-RADS for all thyroid nodules to standardize reporting and reduce unnecessary biopsies of benign nodules.
United Kingdom: The British Thyroid Association (BTA) guidelines incorporate TI-RADS alongside their own U-classification system. NHS radiology departments increasingly adopt ACR TI-RADS for consistency with international practice.
This calculator is for educational and reference purposes only. Always consult a healthcare professional for medical advice, diagnosis, or treatment.
Frequently Asked Questions
What is the TI-RADS scoring system?
TI-RADS (Thyroid Imaging Reporting and Data System) is a standardized scoring system developed by the American College of Radiology (ACR) to assess thyroid nodules found during ultrasound. It assigns points based on five ultrasound features — composition, echogenicity, shape, margin, and echogenic foci — to determine the risk of malignancy and guide fine needle aspiration (FNA) decisions.
What do the TI-RADS categories mean?
TR1 (0 points): Benign, 0.3% malignancy risk, no FNA needed. TR2 (2 points): Not suspicious, 1.5% risk, no FNA needed. TR3 (3 points): Mildly suspicious, 4.8% risk, FNA if ≥2.5 cm. TR4 (4-6 points): Moderately suspicious, 9.1% risk, FNA if ≥1.5 cm. TR5 (≥7 points): Highly suspicious, 35% risk, FNA if ≥1.0 cm.
How is the TI-RADS score calculated?
The TI-RADS score is the sum of points from five categories: Composition (cystic/spongiform 0, mixed 1, solid 2), Echogenicity (anechoic 0, hyper/isoechoic 1, hypoechoic 2, very hypoechoic 3), Shape (wider-than-tall 0, taller-than-wide 3), Margin (smooth 0, lobulated 2, extrathyroidal 3), and Echogenic foci (none 0, macrocalcifications 1, peripheral 2, punctate 3). Foci scores add together when multiple types are present. Maximum possible score is 17.
When is FNA recommended based on TI-RADS?
FNA is recommended for TR3 nodules ≥2.5 cm, TR4 nodules ≥1.5 cm, and TR5 nodules ≥1.0 cm. TR1 and TR2 nodules do not require FNA. Follow-up ultrasound is recommended for TR3 nodules ≥1.5 cm at 1, 3, and 5 years; TR4 nodules ≥1.0 cm at 1, 2, 3, and 5 years; and TR5 nodules ≥0.5 cm annually for up to 5 years.
Is the TI-RADS system used outside the United States?
Yes, the ACR TI-RADS system is adopted by radiology practices worldwide including in India, the UK, Canada, Australia, and across Europe. While the ACR guidelines are the most widely used, some regions may use alternative systems like the EU-TIRADS (European Thyroid Association) or K-TIRADS (Korean Society of Thyroid Radiology), but the ACR system remains the international standard for thyroid nodule risk stratification.
What is a healthy TI-RADS score?
A score of 0-2 points (TR1 or TR2) is considered low risk and requires no follow-up. TR1 (0 points) has a 0.3% malignancy risk and TR2 (2 points) has a 1.5% risk. These are effectively benign or not suspicious categories, and no further intervention is typically needed.
Can TI-RADS be used for all thyroid nodules?
TI-RADS is designed for thyroid nodules identified on ultrasound. If features are indeterminate (e.g., unclear calcification or unassessable margins), the ACR recommends defaulting to solid composition and isoechoic echogenicity, with ill-defined margin. Nodules with benign features like pure cysts or spongiform appearance score 0 points and require no workup.
How accurate is the TI-RADS calculator?
This calculator uses the official ACR TI-RADS scoring criteria from the 2017 ACR white paper. The system has been validated in multiple studies worldwide with reported sensitivity of 82-97% for detecting malignant thyroid nodules at the TR4/TR5 cutoff. However, this tool is for educational reference only and should not replace evaluation by a qualified healthcare professional.