The role of resistive index in the diagnosis of Hashimoto thyroiditis: A cross-sectional study

The diagnostic role of Doppler ultrasonography regarding Hashimoto thyroiditis (HT) is not fully established. We examined intraparenchymal resistive index (RI) as a Doppler parameter, thyroidal vascularity and other Gray-Scale findings in adults with HT in order to evaluate the clinical feasibility of RI in the diagnosis of this disease. The study included 48 women aged 20 to 50 years who had recently been diagnosed with HT. These participants, who were either euthyroid or sub-clinically hypothyroid during the study period, underwent sonographic examination. Thyroid glands were classified into 4 distinct patterns, using the Color Doppler Scale introduced by Schultz et al and also based on Sostre and Reyes Gray-Scale Grading System they were classified into 4 Grades. Intraparenchymal RIs were obtained in 2 locations within each lobe of the thyroid gland. Gray-Scale findings were compared to Doppler findings (RI). Also, intraparenchymal RIs were obtained in 45 healthy adults as a control group. The mean RI values were determined by calculating the mean of the RI measurements obtained from both lobes of each participant in the patient and control groups. The mean RI value was found to be 0.57 ± 0.05 (range 0.5-0.7) cm/s in patient group and 0.54 ± 0.05 (range 0.47-0.7) cm/s in control group. The results were distributed as follows: pattern 0 was observed in 22 cases, pattern I in 15 cases, pattern II in 6 cases, and pattern III in 5 cases. The mean RI values for patients with normal or nearly normal Gray-Scale findings (n = 13) and those with more pronounced Gray-Scale changes (n = 35) showed no significant difference. However, both groups exhibited higher mean RI values compared to the normal adults in the control group. The results highlight that the RI could be an effective and sensitive tool for diagnosing HT through Doppler ultrasonography.