TI-RADS classification by ATA. TIRADS ATA thyroid nodules ultrasound
Updated: Dec 21, 2025
The TIRADS classification refers to the Thyroid Imaging Reporting and Data System (2009), or TI-RADS, an ultrasound classification that evaluates specific characteristics of thyroid nodules (shape, borders, vascularization, presence of microcalcifications, and echogenicity) to categorize them. Each category is associated with a specific risk of malignancy and a corresponding intervention.
It is a reporting and classification system developed by the American Thyroid Association (ATA) to standardize the interpretation and reporting of thyroid gland imaging tests.
Starting with TI-RADS 4 (and sometimes TI-RADS 3 as well), a fine-needle aspiration biopsy (FNAB) of the nodule is recommended. This system allows all physicians evaluating the results of a thyroid ultrasound to use the same nomenclature and terminology.
TI-RADS 1: Normal thyroid.
TI-RADS 2: Benign nodules (0% risk of malignancy).
TI-RADS 3: Nodules probably benign (less than 5% risk of malignancy).
TI-RADS 4: Suspicious Injuries
4a: Nodules of uncertain identity (5-10% risk of malignancy).
4b: Suspicious nodules (10%-50% risk of malignancy).
4c: Highly suspicious nodules (50-85% risk of malignancy)
TI-RADS 5: Nodules probably malignant (more than 85% risk of malignancy).
TI-RADS 6: Malignancy already confirmed by puncture.
The following link will provide you with a calculator that will help you calculate TIRADS