The Observer Variation of Shear Wave Elastography

Background: The main goal of diagnosing thyroid nodules is to differentiate the few malignant from the large background of benign lesion. Currently available pre-operative tests are unable to rule out malignancy in a subset of patients and diagnostic surgery is necessary. Therefore there is a need to develope the available diagnostic tools for the pre-operative diagnostic work-up of thyroid nodules. The study will investigate a novel ultrasonographic technique called Shear Wave Elastography (SWE) in the pre-operative evaluation of thyroid nodules. Hypothesis: 1) SWE is a precise tool for evaluation of thyroid nodules in terms of inter- and intra-observer reliability and day-to-day variation. The study will be conducted as part of a larger PhD study, and an evaluation of the diagnostic value of thyroid SWE will be evaluated in a larger study. Perspectives: An optimization of the pre-operative risk-stratification and diagnosis of thyroid nodules can reduce unnecessary thyroid surgery, with a reduction in morbidity and better use of the economic and surgical resources.

Elasticity Index is obtained by ultrasonographic Shear Wave Elastography performed by two investigators on the same day. The inter- and intra-observer variation and day-to-day variation is calculated

Repeat measures obtained on the same day (ten minutes to one hour between measurements), and measures obtained on a different day (one day to several weeks).

Inclusion Criteria: patients with a thyroid nodule ≥1 cm in largest dimension (solitary or dominating nodule in multinodular goiter), Patients undergoing thyroid surgery. Exclusion Criteria: Nodules located in the isthmus of the thyroid