The effectiveness of color Doppler ultrasonography in differential diagnosis in autoimmune thyroid diseases

Introduction Ultrasonography (US) is used safely for long time morphological evaluation of thyroid disease. Thyroid gland is heterogeneous in autoimmune thyroid disease (ATD), and Hashimato's disease and Graves disease can not be distinguished only by B-mode US findings.Thyroid gland vascularity and blood flow are mainly due to the stimulation of TSH receptors. In some studies it has been suggested that Vmax measurements of the inferior thyroid artery can be used to differentiate Graves cases from other ATD. Purpose To investigate the usefulness of inferior thyroid artery Vmax measurements and inferior thyroid artery/common carotid artery velocity ratio to differentiate Graves patient from Hashimato's patient Method In a prospective study, color Doppler examination of 24 patients (6 Graves and 18 Hashimato patient) who were diagnosed with clinical and laboratory findings and autoimmune thyroid disease were evaluated. Four grades (grade 0-1-2-3) color evaluation were performed from each thyroid parenchyma. Inferior thyroid artery (ITA) and common carotid artery (CCA) Vmax were measured in each patient. From these measurements, the ITA/CCA ratios were calculated. Wilcoxon-Signed-Ranks test was used for statistical comparison of findings. Results The most frequent color pattern in the Graves cases was grade 3 while in Hashimato cases it was grade 0 and grade 1 . In the cases of Hashimato's disease, the mean ITA Vmax measured 51,2 cm/sn, which was significantly lower than tke mean measured 116,3 cm/sn in Graves cases. The ratio of ICA/CCA was significantly lower in Hashimato cases (mean=0,57) than Graves cases (mean=1,08) Conclusion The color Doppler US pattern evaluation and ITA Vmax measurements in addition to B-mode US seem to be successful in differentiating Graves patients from Hashimato's patient. There was a statistically significant difference the ITA/CCA ratios between the two groups. However, there were no statistically significant differences between hyperthroidic Hashimato and Graves cases.