5. Multi-nodule tracker
Save several nodules for comparison. Stored in this browser only (maximum 4 nodules per ACR guidance).
| Nodule | Size | Points | Level | Recommendation | |
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No nodules saved yet. Calculate above, then press “Add to nodule list”.
Frequently asked questions (FAQ)
What is ACR TI-RADS?
ACR TI-RADS (Thyroid Imaging Reporting and Data System) is an ultrasound-based thyroid nodule risk stratification system published by the American College of Radiology in 2017 (Tessler et al.). It assigns 0–3 points across five ultrasound feature categories — composition, echogenicity, shape, margin, and echogenic foci — then groups nodules into TR1 (benign) through TR5 (highly suspicious), with size thresholds for fine-needle aspiration (FNA) biopsy or ultrasound follow-up.
How does ACR TI-RADS differ from ATA and EU-TIRADS?
All three assess thyroid nodule malignancy risk from ultrasound, but with different approaches. ACR TI-RADS uses a 0–3 point system per feature summed into TR1–TR5, so two nodules at the same level can have different feature combinations. The 2015 ATA guidelines use sonographic patterns (e.g., highly suspicious if solid hypoechoic with one suspicious feature). EU-TIRADS uses pattern categories 1–5 without a point system. ACR TI-RADS generally uses more conservative size thresholds, reducing unnecessary biopsies.
Does a TR5 result mean the nodule is cancer?
No. TR5 means highly suspicious based on ultrasound appearance, with a malignancy risk of about 35% in the ACR validation — meaning most TR5 nodules still turn out benign. Only FNA cytology or histopathology can confirm a diagnosis. This calculator’s result is risk stratification, not a diagnosis.
Why does biopsy/FNA wait for a certain size?
ACR TI-RADS deliberately uses conservative size thresholds (e.g., TR5 is only biopsied at ≥1.0 cm and TR3 at ≥2.5 cm) to reduce biopsies of benign nodules without missing clinically significant cancers. Nodules below the threshold are usually monitored with periodic ultrasound.
Are echogenic foci points summed?
Yes. Unlike the first four categories where only one feature may be selected, in the echogenic foci category all visible features are summed. For example, a nodule with macrocalcification (1 point) plus punctate echogenic foci (3 points) gets 4 points for this category.
What if the total is only 1 point?
The ACR guideline defines TR1 for 0 points, TR2 for 2 points, TR3 for 3 points, TR4 for 4–6 points, and TR5 for ≥7 points. A total of 1 point (e.g., from mixed composition alone) is not explicitly named; this calculator manages it as TR2 (not suspicious) with an explanatory note in the results.
Why are cystic or spongiform nodules automatically TR1?
Per the 2017 ACR white paper, cystic or almost entirely cystic nodules and spongiform nodules are considered benign (TR1) without needing to score other categories, because this pattern is essentially always benign. This calculator applies that rule automatically.
What is a comet-tail artifact and why 0 points?
A comet-tail artifact is a repeating echogenic line behind a small echogenic focus, typical of colloid material. A large comet-tail artifact indicates benignity and is therefore worth 0 points; small punctate echogenic foci without acoustic shadowing are suspicious (3 points) because they may represent microcalcifications.
How often is ultrasound follow-up done?
When a nodule meets the follow-up threshold: TR3 is repeated in years 1, 3, and 5; TR4 in years 1, 2, 3, and 5; TR5 every year for 5 years. This schedule follows the 2017 ACR TI-RADS recommendations and may be adjusted by the treating physician.
Does this calculator replace the radiologist?
No. TI-RADS is designed to be interpreted from ultrasound images by trained professionals. This calculator helps you understand how points are calculated and what each level means, but biopsy, follow-up, and diagnosis decisions remain with the radiologist and the patient’s treating physician.