EU-TIRADS: Risk Stratification of Thyroid Nodules
What is EU-TIRADS
EU-TIRADS (European Thyroid Association, Russ et al., 2017) is a simplified ordinal risk stratification system for the malignancy of thyroid nodules. It includes categories 1–5 and, unlike some protocols that use designations like "TI-RADS 4A," does not contain lettered subgroups within categories.
Assessment Principle
EU-TIRADS emphasizes the assessment of 5 echostructure patterns. This distinguishes it from ACR TI-RADS, where features are assessed differently. There are no subgroups within categories (e.g., 4A/4B) in the system.
In general, TIRADS systems are modeled after BI-RADS for mammography: a category is assigned to a nodule based on the number of suspicious ultrasound features identified, which include (Orloff, 2017):
- solid structure;
- hypoechogenicity or marked hypoechogenicity;
- microlobulated or irregular margins;
- microcalcifications;
- taller-than-wide shape.
System Objective
The primary purpose of EU-TIRADS is to provide a simple guide for using specific ultrasound features to identify thyroid carcinomas with high sensitivity while maintaining a high negative predictive value (NPV). This, in turn, should reduce the number of unnecessary fine-needle aspiration biopsies (FNA) (Russ et al., 2017).
Role in Clinical Practice
Modern systems (ACR TI-RADS and EU-TIRADS) offer a clearer quantitative link through the "size + category → management" scheme and are better validated in subsequent studies, thus recommended as the current standard: ACR in the USA, EU-TIRADS in Europe. In Russia, ACR TI-RADS is more commonly used (Medtrain Consortium, 2026).
Frequently asked questions
Are there subgroups 4A/4B in EU-TIRADS?
No. EU-TIRADS includes categories 1–5 without lettered subgroups. Designations like "TI-RADS 4A" do not correspond to either EU-TIRADS or ACR TI-RADS.
What is the basis for nodule assessment in EU-TIRADS?
It is based on the assessment of 5 echostructure patterns of the nodule. Unlike ACR TI-RADS, features are assessed differently, with a focus on echostructure patterns.
What is the main goal of EU-TIRADS?
To provide a simple guide for applying ultrasound features to identify carcinomas with high sensitivity and high NPV, allowing for a reduction in unnecessary FNAs.
Which system should be used in Russia?
In Russia, ACR TI-RADS is more commonly used; EU-TIRADS is recommended as the standard in Europe, ACR in the USA.