Factors Affecting Thyroid Elastography in Healthy Children and Patients with Hashimoto's Thyroiditis.

Abstract

Hashimoto's thyroiditis (HT) is the most common form of thyroiditis in childhood. In addition to thyroid ultrasonography, shear-wave elastography (SWE) can evaluate thyroid parenchyma tissue stiffness, and more detailed findings can be obtained. We aimed to evaluate the relationship between SWE values and clinical, biochemical and hormonal parameters of individuals both in patients with HT and in healthy individuals. We compared 46 newly diagnosed HT cases with 46 healthy controls. We examined the effect of all metabolic parameters and thyroid-related markers on SWE values. The mean SWE values in patients with euthyroid HT were 12.5 ± 5.1 kilopascal (kPa), it was 8.2 ± 2.82 kPa in healthy controls (p< 0.001). Although the clinical (age, gender and body mass index) and laboratory parameters (such as thyroid function tests, HOMA-IR, IGF-1 values, which we think may affect SWE scores) of children with HT and healthy controls were statistically similar (p> 0.05), except for thyroid autoantibodies and thyroglobulin, SWE values and thyroid volume were significantly higher in individuals with HT (p< 0.001). Multiple linear regression analysis was performed to evaluate the direction and degree of the effect of the variables on thyroid elasticity scores, it was observed that age (p: 0.002), BMI SDS (p: 0.04) and Anti-TPO (p: 0.008) levels were effective on the thyroid elasticity score in the regression model. We detected a SWE cut-off value of 9.68 kPa with 68% sensitivity and 72% specificity, a 70% positive predictive value, and a 69% negative predictive value in thyroid elastography to differentiate cases with HT from healthy controls. Our results show that any metabolic factor other than BMI SDS has no effect on SWE scores, especially in healthy children. There is a positive correlation between BMI SDS and SWE in healthy children (r=0.353; p=0.02), but not in the patients with HT (r=0.196; p=0.19). Likewise, age is another factor affecting SWE in only healthy children. We do not recommend routine evaluation of any laboratory parameter other than thyroid functions before thyroid elastography.