Elastography of Thyroid Nodules: MPUS by EFSUMB 2026

Clinical Significance of EFSUMB 2026 Update

EFSUMB Guidelines on Multiparametric Ultrasound Thyroid Nodule Evaluation: Part I marks the transition from isolated nodule assessment by grayscale features to multiparametric ultrasound. B-mode remains the foundation: composition, echogenicity, margins, shape, echogenic foci, signs of extrathyroidal extension, and lymph node status form the primary suspicion level. Elastography, Doppler, superb microvascular imaging (SMI), and contrast-enhanced ultrasound (CEUS) add information on mechanical properties and vascularization but do not override TIRADS logic and clinical indications for biopsy.

The main practical takeaway: a stiff nodule requires more careful correlation with grayscale features, while a soft nodule may support a benign interpretation, especially in the absence of suspicious B-mode markers. However, EFSUMB does not propose using a single numerical stiffness threshold for all patients, devices, and techniques.

What Elastography Measures in a Thyroid Nodule

Elastography assesses tissue deformation or shear wave propagation speed as an indirect marker of stiffness. Malignant tumors often exhibit increased stiffness due to cellularity, fibrosis, desmoplasia, and infiltrative growth. However, stiffness is not synonymous with cancer: fibrosis, calcifications, chronic thyroiditis, post-biopsy changes, and significant probe compression can also produce a "hard" appearance.

Therefore, EFSUMB views elastography as a risk modifier. It is particularly useful for nodules with intermediate grayscale features, where B-mode does not provide a clear direction for observation or FNA. In clearly suspicious nodules, a soft elastogram should not automatically reduce vigilance.

Qualitative Logic of Stiffness Interpretation

The document emphasizes the need to interpret stiffness in the context of image quality, examination technique, and nodule morphology. A universal numerical boundary in kPa or m/s is not transferable between strain elastography, point shear wave elastography, and 2D shear wave elastography methods, nor between equipment manufacturers.

Where Elastography is Most Useful

The greatest value of elastography is in nodules with unclear grayscale semiotics. If a nodule is solid or predominantly solid, without coarse calcifications and accessible for stable scanning, stiffness can clarify risk. The method also helps select the most informative area for biopsy: cystic, necrotic, and coarsely calcified zones should be avoided, focusing on solid and suspicious MPUS areas.

In multinodular goiter, elastography should not become a mechanical ranking of all formations solely by stiffness. Priority remains with nodules with suspicious B-mode morphology and clinically significant formations; elastography adds an argument but does not replace a systematic examination of the entire gland and regional lymph nodes.

Limitations: When Stiffness Misleads

EFSUMB specifically highlights the technical dependency of elastography. Incorrect compression, respiratory and swallowing movements, unstable ROI positioning, proximity to the trachea or vessels, shallow depth, and uneven probe contact alter results. In strain elastography, uniform minimal pressure is critical; in shear wave methods, correct placement of the measurement window and absence of wave propagation artifacts are essential.

Calcified nodules may appear artificially stiff. Cystic and degenerative components, on the other hand, disrupt measurement comparability. In diffuse autoimmune thyroiditis, the parenchyma background changes, so the nodule's relation to surrounding tissue and absolute stiffness values require caution. The conclusion should include not only the result but also an indication of factors limiting reliability.

Doppler and SMI: Vascular Pattern as an Addition, Not a Diagnosis

Color and power Doppler assess macrovessel patterns, while SMI detects lower-speed microvascular signals. In MPUS, this is important because malignant nodules may have chaotic, peripherally discontinuous, or intranodular vascularization, but the vascular pattern alone is insufficiently specific. Lack of significant blood flow does not rule out cancer, and hypervascularity occurs in benign hyperplasia and inflammation.

Practically, Doppler/SMI is useful for three tasks: confirming the solidity of a suspicious area, selecting a viable zone for FNA, and distinguishing vascular structures from echogenic foci or cystic septa. Vascular visualization modes should be described alongside B-mode and elastography, not as a separate line "blood flow present/absent".

CEUS in Thyroid Nodule Evaluation

CEUS adds dynamic information on microcirculation after the administration of an ultrasound contrast agent. In the context of EFSUMB, it is not a screening mode for every nodule but a tool for clarification in selected clinical scenarios: ambiguous structure, need to assess viable areas before biopsy, complex differentiation of degenerative changes and solid tissue.

Contrast study should not be used as the sole criterion for benignity or malignancy. Its strength lies in localizing perfused areas and increasing confidence when correlated with B-mode, elastography, and vascular modes. In suspected necrotic tumors, CEUS helps avoid biopsying non-viable zones.

How MPUS Influences FNA Decision

The decision on fine-needle aspiration biopsy remains integral: risk category by grayscale features, size, history, symptoms, growth dynamics, and lymph node status are considered. MPUS does not override TIRADS threshold logic but can alter physician confidence in borderline cases. A stiff nodule with suspicious contours and echogenic foci strengthens indications for morphological verification. A soft, avascular, or typically degenerative nodule without suspicious features supports an observational approach if it aligns with TIRADS and clinical context.

For protocol, it is important to separate facts and conclusions: describe B-mode, elastographic pattern, Doppler/SMI, or CEUS findings separately, then formulate an integral risk category and recommendation. It is unacceptable to write "elastography excludes cancer" or "stiff nodule equals cancer".

What to Write in the Conclusion

An optimal conclusion according to EFSUMB logic should be reproducible. It should indicate the location and size of the nodule, grayscale features, presence of suspicious lymph nodes, elastography result with quality assessment, vascular pattern, and, if CEUS was performed, the nature of contrast enhancement. The final phrase should answer the clinical question: observation, FNA, repeat ultrasound in dynamics, or further lymph node examination.

If elastography is technically limited, this should be explicitly stated. Such an indication protects against overdiagnosis and helps the clinician understand why stiffness was not used to increase or decrease risk.