Endocrine Abstracts

Objective: In this study, we investigated the utility of Doppler and microvascular imaging in diagnosing benign and malignant thyroid nodules according to the TI-RADS (Thyroid Imaging Reporting and Data System) and pathologic subtypes of thyroid malignancy.

Methods: Total 113 pathologically confirmed thyroid nodules (n =72 (63.7%) benign, n =41 (36.3%) malignant) from103 patients who visited for evaluation of thyroid nodules in single tertiary referral center between Feb. 2022 and Sep. 2022 were retrospectively included in this study. Two experienced radiologists reviewed US findings including color Doppler and microvascular pattern and scored using 4-scale visual analysis in consensus. US patterns of all nodules were categorized based on Korean thyroid imaging reporting and data system (K-TIRADS).

Results: The malignant nodules consist of 32 papillary carcinomas, 8 follicular variant papillary carcinomas and 1 lymphoma. The mean diameter of the nodules was 1.5 ± 1.1 cm (range 0.5 ~ 5.6 cm). All thyroid nodules were described with US lexicon proposed by K-TIRADS, and all US lexicons were significantly different between benign and malignant nodules (P ≤ 0.08). Color Doppler score was also significantly different between benign and malignant nodules (P< 0.000). The nodules were categorized as benign (n =1, 0.9%), low suspicion (n =39, 34.5%), intermediate suspicion (n =43, 38.1%), and high suspicion (n =30, 26.5%). In subgroup analysis, there were no significant differences in color Doppler and microvascular imaging between benign and malignant nodules that were categorized as low and intermediate suspicion category. However, among the high suspicion nodules, benign nodules showed significantly higher vascularity scores when compared with malignant nodules (P= 0.018 in Doppler and P = 0.051 in microvascular). Classic PTC showed lower vascular scores in color Doppler and microvascular imaging while follicular variant PTC showed higher vascular scores.

Conclusion: Doppler and microvascular imaging can be helpful in differentiating benign and malignant thyroid nodules, especially for highly suspicious US featured thyroid nodules.