Comparison of thyroid scintigraphy and ARFI-elastography for autoimmune thyroid disease

Autoimmune thyroid diseases are common in the population and are often present with similar clinical and laboratory findings. Thyroid scintigraphy is an imaging technique commonly used in the diagnosis and follow of autoimmune thyroid diseases and it allows the quantitative evaluation. ARFI (Acoustic radiation force impulse ) elastography is a new ultrasound modality, which can measure and allows the quantification of tissue stiffness considering the speed of sound wave propagation in the tissue. In this study, our aim is to compare the ARFI elastographic and scintigraphic quantitative data obtained from the thyroid gland and to evaluate the diagnostic value of ARFI elastographic measurements in the autoimmune thyroid diseases. We included in the study a total of 61 patients (41 women, 20 men) including 24 Graves' disease, 15 Hashimoto disease and 22 control subjects. The mean age of patients was 33.9 ± 10.9 years. Patients with thyroid nodules were not included in the study. Thyroid uptake was performed with Tc 99m pertechnetate and the elastosonography score of the thyroid gland was determined with ARFI elastosonography. The findings of both disease groups were statistically compared with each other and the findings of the control group. For thyroid uptake test; a statistically significant difference was found between the two disease groups (p< 0.001) and between the each disease and the control group (p< 0.001 for Hashimoto group, p< 0.001 for Graves group). However, for ARFI method; a statistically significant difference was not found between the two disease groups (p: 0.336) and between each disease and the control group (p: 0.14 for Hashimoto group, p: 0.08 for Graves group). A weak correlation was found between the thyroid uptake values and ARFI scores (p: 0.048, r: 0.255). As a result, the thyroid scan and thyroid uptake measurements are extremely valuable in the diagnosis of the autoimmune thyroid diseases and ARFI elastosonographic measurements do not seem to replace the scintigraphic data. KEYWORDS: Thyroid scintigraphy, thyroid uptake, ARFI, Graves' disease, Hashimoto disease