Elastography of Thyroid Nodules: Strain Ratio, Stiffness Scales, and Indications for FNA
The Role of Elastography in Evaluating Thyroid Nodules
According to the EFSUMB guidelines on multiparametric ultrasound of thyroid nodules (Cantisani et al., 2026) and the ACR-SRU practice parameter (2024), ultrasound elastography is considered an adjunct method to TI-RADS for differentiating benign from malignant lesions. The combination of TI-RADS with elastography improves cancer risk stratification (Xue et al., 2016; Stoian et al., 2015).
Methods: Strain Ratio and Shear-Wave
Two main approaches are mentioned in the excerpts:
| Method | Type | Source |
|---|---|---|
| Strain ratio (SRE) | Semi-quantitative (compression elastography) | Cantisani et al., 2019; Celletti et al., 2021 |
| 2D shear-wave (SWE) | Quantitative (Young's modulus) | Anvari et al., 2016; Nattabi et al., 2022 |
Direct assessment of tissue Young's modulus using the shear-wave method has been studied, including in follicular neoplasms (Anvari et al., 2016). Specific stiffness thresholds and scales (e.g., Asteria/Rago scores) are not provided in the available excerpts [clarification needed].
Indications for Indeterminate Cytology
Special attention is given to the use of elastography in nodules with indeterminate cytology results. The diagnostic value of preoperative elastography was evaluated (Ucan et al., 2021), and the diagnostic effectiveness of TI-RADS, SRE, and SWE was compared (Celletti et al., 2021). Data on which method provides the best diagnostic effectiveness in this group require clarification from the full text [clarification needed].
Relation to Indications for FNA
According to the available excerpts, elastography is used in conjunction with TI-RADS for malignancy risk stratification, which influences the selection of nodules for fine-needle aspiration biopsy (FNA). Specific decision-making algorithms for FNA based on elastographic data are not detailed in the provided excerpts [clarification needed].
Frequently asked questions
What elastography methods are used for thyroid nodules?
Semi-quantitative strain ratio (SRE) and quantitative 2D shear-wave elastography (SWE), including Young's modulus assessment (EFSUMB, 2026; ACR-SRU, 2024).
Does elastography improve the accuracy of TI-RADS?
Yes, the combination of TI-RADS with elastography improves cancer risk stratification and differentiation of benign and malignant nodules (Xue et al., 2016; Stoian et al., 2015).
Is elastography useful for indeterminate cytology?
The diagnostic value of preoperative elastography and the comparison of TI-RADS, SRE, and SWE in nodules with indeterminate cytology have been studied (Ucan et al., 2021; Celletti et al., 2021).
What strain ratio thresholds should be used?
Specific numerical thresholds are not provided in the available excerpts [clarification needed] — reference to the full text of the guidelines is necessary.