Elastography and EU-TIRADS: Integration of Nodule Stiffness into Thyroid Malignancy Risk Stratification
The risk stratification of thyroid nodule malignancy using the EU-TIRADS system (European Thyroid Association Guidelines for Ultrasound Malignancy Risk Stratification of Thyroid Nodules in Adults; Russ et al., 2017) is based on grayscale ultrasound features. Elastography is considered a component of a multiparametric approach, complementing TIRADS categorization with information on the mechanical stiffness of tissue.
The Role of Elastography in Multiparametric Assessment
According to EFSUMB materials on multiparametric thyroid ultrasound (Cantisani et al., 2026) and EFSUMB recommendations on elastography in non-hepatic applications (Săftoiu et al., 2019), nodule stiffness assessment is an additional characterization tool, not an independent stratification system. The historical basis for using elastography to predict thyroid nodule malignancy dates back to the work of Rago et al. (2007).
Methods: Strain and Shear Wave
Two main technologies are used in clinical practice. The semi-quantitative strain ratio and quantitative 2D shear wave elastography (SWE) were prospectively evaluated in association with TIRADS classification for thyroid nodule characterization (Cantisani et al., 2019). The diagnostic efficacy of quantitative 2D-SWE for differentiating benign and malignant nodules was analyzed in a systematic review and meta-analysis (Nattabi et al., 2022).
Integration with EU-TIRADS
Combining elastographic data with the TIRADS category aims to refine nodule characterization in addition to grayscale features. Specific threshold values for strain ratio and SWE (kPa), as well as the algorithm for integrating them into biopsy decision-making within EU-TIRADS, are not provided in the source fragments. [clarify]
| Parameter | Method | Source (by fragments) |
|---|---|---|
| Strain ratio (semi-quantitative) | Compression elastography | Cantisani et al., 2019 |
| 2D-SWE (quantitative) | Shear wave elastography | Cantisani et al., 2019; Nattabi et al., 2022 |
| EU-TIRADS | Grayscale stratification | Russ et al., 2017 |
The performance of elastography is regulated by the ACR-SRU Practice Parameter for the Performance of Ultrasound Elastography (ACR/SRU, 2024), where the technology is also considered in the context of reducing the number of unnecessary biopsies (analogous to data for breast tissue).
Frequently asked questions
Does elastography replace EU-TIRADS?
No. According to EFSUMB materials, elastography is an additional parameter of multiparametric ultrasound, applied in association with TIRADS classification, not an independent stratification system.
What elastography methods are applicable to thyroid nodules?
Semi-quantitative strain ratio and quantitative 2D shear wave elastography (SWE); both were evaluated in association with TIRADS (Cantisani et al., 2019).
What stiffness threshold values should be used?
Specific numerical thresholds for strain ratio and SWE are not provided in the source fragments. [clarify]
Can elastography reduce the number of biopsies?
The potential to reduce the number of unnecessary biopsies is discussed in the ACR-SRU Practice Parameter (2024), including data on SWE.
Which document regulates the performance of elastography?
ACR-SRU Practice Parameter for the Performance of Ultrasound Elastography (ACR/SRU, 2024) and EFSUMB recommendations on elastography in non-hepatic applications (Săftoiu et al., 2019).