[Thyroid Elastography]

Thyroid nodules are a common finding especially in regions with inadequate iodine supply. Ultrasound is an accurate method for the detection of thyroid nodules, but it has a low accuracy for the differentiation between benign and malignant thyroid nodules. Therefore, in patients with normal thyroid stimulating hormone fine-needle-aspiration-biopsy (FNAB) is presently recommended as supplementary diagnostic methods in the evaluation of thyroid nodules. However, a relevant number of patients with the final diagnosis of benign thyroid nodules receive thyroid surgery more for diagnostic than for therapeutic purposes. A classical criterion of malignancy is a hard or firm consistency upon palpation or ultrasound-probe pressure. Previously this attribute was subjective and dependent on the experience of the examiner. With the introduction ultrasound-based elastography a reproducible qualitative assessment of tissue consistency became available. The aim of the present article is to provide an update of the literature on different available techniques and the results reported both for thyroid nodules differentiation and for diffuse thyroid disease evaluation. Advantages and limitations of elastography are also discussed.