Evaluation of the thyroid blood flow with Doppler ultrasonography in healthy school-aged children.

OBJECTIVE: To determine the relationship between thyroid blood flow and anthropometric measurements, pubertal stage, and thyroid and gonadotropic hormones. MATERIALS AND METHODS: We examined 123 healthy school-aged children prospectively (69 boys (56.1%) and 54 girls (43.9%), 7-17 years old). Their sex, age, body weight, height, body mass index (BMI), and pubertal stage were determined. Serum thyrotropin, free thyroxine, luteinizing hormone, and follicle stimulating hormone were measured in both genders, along with testosterone in boys and estradiol in girls. The peak systolic velocity (PSV), resistance index (RI), and pulsatility index (PI) of the superior thyroid artery were determined. The correlations between the Doppler parameters and these factors were investigated. RESULTS: There were no differences in age, weight, height, BMI, thyroid volume, PSV, RI, or PI between boys and girls (P>0.05). The PSV and PI showed strong correlations with age, height, weight, puberty stage, thyroid volume, and BMI. The RI showed a strong inverse correlation with age, height, weight, puberty stage, and thyroid volume and a weak inverse correlation with the BMI. CONCLUSION: Determination of the thyroid arterial flow in normal healthy children is important during a Doppler ultrasound (US) examination. Doppler US parameters and their percentiles should be described in healthy children from different age groups, and these percentiles will aid in interpreting Doppler US in children.