The peak systolic velocity of the common carotid artery and superior thyroid artery as an indicator of thyroid function.

We investigated the efficacy of color duplex ultrasound in the detection of the thyroid's functional state on 132 consecutive patients referred for morphological examination of the thyroid gland. The patients were classified into 3 groups: Group A (euthyroid, n = 108), Group B (diffuse toxic goiter, n = 16) and Group C (hyperthyroidism on medical treatment for 1 to 4 months, n = 8), according to the serum thyroid hormones' determination and the patient's clinical history. The peak systolic velocity (Vmax) of the bilateral common carotid arteries (CCAs) and superior thyroid arteries (STAs) were measured. The Vmax of CCAs was 90.33 +/- 23.13 cm/sec (mean +/- standard deviation), 148.44 +/- 28.97 cm/sec and 84.75 +/- 13.58 cm/sec in Groups A, B and C. The hyperthyroid patients had a significantly higher Vmax of CCAs than the euthyroid subjects (p less than 0.001) and those hyperthyroid patients receiving medical treatment (p less than 0.001). The Vmax of STAs was 32.4 +/- 13.49 cm/sec for the non-nodular lobes and 38.78 +/- 13.76 cm/sec for the nodular lobes in the euthyroid subjects. There was no difference between the non-nodular and nodular lobes. The Vmax of STAs was 91.69 +/- 32.02 cm/sec and 62.75 +/- 18.19 cm/sec for Groups B and C; both were higher than the euthyroid (p less than 0.001 and p less than 0.05 respectively). Patients with hyperthyroidism had a lower Vmax of STAs after medical treatment (Group B vs Group C, p less than 0.01). It is our conclusion that cases of hyperthyroidism have a higher volume of blood flow of both the common carotid arteries and thyroid arteries than the euthyroid cases.(ABSTRACT TRUNCATED AT 250 WORDS)