COLOR DOPPELER OF SUPERIOR THYROID ARTERY IN EUTHYROID INDIVIDUL: AN OBSERVATIONAL STUDY

Abstract

INTRODUCTION: The estimate of blood flow mode is very subjective and also difficult for quantification. Also for quantification of thyroid blood supply complicated post-examination software processing is required. Hormonal assays are more specific in evaluating thyroid status but ultrasonography of thyroid gland is routinely done. Thyroid glandular parenchyma are often found normal in early stages of diseases. This study was carried out to find the normal ranges of Doppler indices of superior thyroid arteries.

MATERIAL AND METHODS: A Study subject includes clinically euthyroid individuals and not diagnosed previously of any thyroid disease and hormonal assay are normal. STA was identified as the first branch of external carotid artery that arises anteriorly at the level of hyoid bone. The artery could be traced up till the upper pole of thyroid gland, where the artery was sampled using color Doppler mode. Peak systolic velocity (PSV), pulsatility index (PI), and resistivity index (RI) of both the STAs were calculated.

RESULTS: Ultrasonography of all 134 subjects were carried out of which in 15 subjects some abnormality or nodule was detected hence were excluded from the study. Doppler evaluation of bilateral STAs was done in the remaining 119 individuals. Age range was between 23 years to 69 years. Study includes 79 female and 40 male. All subject has undergone hormonal assay which was normal. Of the total 119 subjects included in the study 40(33.6%) were male and 79(66.4%) were female. Mean age of male subjects was 36±15.7 years and of female subjects was 37±17.9. STAs could be traced at the superior poles in 110 subjects in 9 subjects vessels were sampled closer to their origins from the external carotid arteries. Average peak systolic velocity of female was 16.51±4.9 cm/sec and of male was 17.24±5.9 cm/sec with total average was 16.84±5.1 cm/sec. Pulsatility index in female was 0.82±0.29 and in males it was 1.08±0.39 with total average 0.97 ±0.35. Resistivity index in female was 0.52±0.11 and in males it was 0.61±0.21 with total average 0.58±0.17. While statistical significance was noted in Pulsatility index and Resistivity index. CONCLUSION: Mean values of Doppler indices of STA in euthyroid individuals in which peak systolic velocity was 16.84±5.1 cm/sec. Pulsatility index was 0.97 ±0.35 and 0.58±0.17, Resistivity index was 0.58±0.17. These values can be used as reference for future studies.