The Value of Shear Wave Elastography and Velocity Standard Deviation Value in the Differentiation of Subacute Thyroiditis and Chronic Autoimmune Thyroiditis

D. The value of shear wave elastography and velocity standard deviation value in the differentiation of subacute thyroiditis and chronic autoimmune thyroiditis. Cerrahpaşa Med J. 2021;XX:1-6. Abstract Objective: To evaluate the possibility of distinguishing between subacute thyroiditis and chronic autoimmune thyroiditis, which can mimic each other in terms of clinical, laboratory, and radiological findings with shear wave elastography. Methods: Patients who were diagnosed with subacute thyroiditis according to their clinical, laboratory, and radiological characteristics (Group 1) and patients using drugs for chronic autoimmune thyroiditis (Group 2) were included in the study. All patients underwent shear wave elastography examination after thyroid ultrasonography. V mean and velocity standard deviation ( V sd ) values were measured in both lobes with shear wave elastography. Grayscale and Doppler sonography imaging features of the patients (parenchymal heterogeneity, perithyroidal lymph node, parenchymal vascularity) and laboratory values (TSH, anti-thyroid peroxidase antibody, anti-thyroglobulin) were recorded. It was evaluated statistically whether there was a significant difference between the groups in terms of these parameters and shear wave elastography values. Results: Although there was no significant difference between the groups in terms of clinical, laboratory, and radiological features, the total thyroid gland volume was higher in Group 1. The rate of parenchymal heterogeneity and hypovascularity was higher in Group 1. No significant difference was found in terms of elastographic parameters. The elastographic stiffness was higher in Group 1 than in Group 2 for both lobes. Conclusion: In the presence of hypovascular heterogeneous patchy areas with increased thyroid gland sizes, it is more possible to support the diagnosis of subacute thyroiditis by ultrasonography. The V sd value of 0.4 and above with elastography strengthens the diagnosis in terms of subacute thyroiditis.