The diagnosis and evaluation of diffuse thyroid pathologies is often a challenge for clinicians. Ultrasonography has an essential contribution in thyroid imaging, but elastography adds more accuracy. Frequently used in the evaluation of thyroid nodules, elastography has become a necessary tool in assessing the risk of malignancy. Diffuse thyroid pathologies such as Graves’ disease, chronic autoimmune thyroiditis, and subacute thyroiditis, are diagnosed based on laboratory tests completed with imaging. Recently it has been shown that elastography is useful in the evaluation and differentiation of these cases due to the differences in elasticity. This chapter describes the general principles of shear-wave elastography, examination technique, features found in diffuse thyroid disease, but also the limitations of this type of investigation for a better understanding of its use in assessing diffuse thyroid pathology.
Part of the book: Elastography
Ultrasonography provides a primary stratification of the malignancy risk of thyroid nodules for selecting those that need further evaluation by fine-needle aspiration cytology (FNAC). Ultrasound elastography (USE) methods have been more recently proposed as a promising tool, aiming to increase the accuracy of baseline ultrasound. By means of USE, stiffness is assessed as an indicator of malignancy. Strain elastography was the first method used in thyroid imaging, with very good accuracy in discerning thyroid cancer. More recently, 2D shear-wave elastography also confirmed to be a valuable tool with similar outcomes. The advantages, limitations, and technical details of the elastography methods currently used in assessing thyroid morphology, particularly thyroid nodules, will be presented and compared in this chapter.
Part of the book: Elastography