Aim: The aim of this study is to evaluate and compare the values of strain index ratio as measured by real-time ultrasound elastography in healthy subjects and in adolescent patients with Hashimoto Thyroiditis (HT). Our aim is also to determine cut-off value of strain index ratio, obtain reference values and evaluate if we can use this values in diagnosis and follow-up.
Material and Methods: A total of 76 patients with HT and 46 healthy controls were included in the study group, prospectively examined by strain sonoelastography. The strain index ratio was defined as the ratio of thyroid gland strain value divided by the strap muscle strain value. Hi-Vision Preirus ultrasound device (Hitachi Tokyo, Japan) with 7-13 MHz linear-array broadband probe was used.
Results: The mean strain index ratio was higher in HT patients, 1.2 ± 0.2, than in the control group, 0.77 ± 0.18 (p<0.01). There was a positive correlation between anti-thyroid peroxidase (anti-TPO) and strain index ratio (r=0.439, p<0.01). However, there was no correlation between Anti-Thyroglobulin (ATG) and strain index ratio. The area under the Receiver Operating Characteristics (ROC) curve for HT was 0.929, and the optimal cut-off value for elastography (strain index ratio) in HT prediction was >0.98 (83% sensitivity, 93% specificity, +LR: 13, - LR: 0.18).
Conclusion: Strain index ratio index measured by real time strain elastography was significantly higher in HT than in normal thyroid parenchyma. Strain elastography methods can be used to evaluate the degree of fibrosis in patients with HT. Therefore these values can be used as an adjunct to conventional B-mode ultrasonography in the diagnosis of Hashimoto thyroiditis in adolescents.