Gintaras Kuprionis1, Raimondas Valickas1, Rasita Pavilionė1, Žygimantas Štaras1, Ugnė Marcinkutė1
1Lithuanian University of Health Sciences, Kaunas, Lithuania
Introduction: There have been various systems for identifying risk of thyroid nodule malignancy using ultrasound (US), with the most recent being 2017 American College of Radiology proposed TI-RADS. However, this system does not take vascular patterns into account. The aim of this study is to determine the role of gray scale and color Doppler ultrasound in differentiating benign and malignant thyroid nodules
Methods: A total of 180 ultrasound images of patients with thyroid nodules were analyzed. Nodule composition, shape, margin, echogenicity, echogenic foci and vascular patterns were evaluated. The results were compared with histology findings
Results: 98 (54.4%) thyroid nodules were benign and 82 (45.5%) – malignant. Compared to malignant, more benign thyroid nodules (80.6%) were bigger than 1 cm, p < 0.001). Benign and malignant thyroid nodules did not significantly differ in frequency of composition or echogenicity (p > 0.05). Round and taller-than-wide shape, lobulated or irregular margin, microcalcifications were more common among malignant nodules (p < 0.05). Mean total TI-RADS score was significantly higher among malignant thyroid nodules compared to benign, p < 0.001. TI-RADS sensitivity in predicting the risk of malignancy was 82.9%, specificity – 69.4%, area under curve – 0.822, while vascularity had sensitivity of 40% and specificity of 36.7%. Mixed vascularity was more common among benign (p = 0.003) and weak perinodular vascularity was more common among malignant nodules (p = 0.048). Weak negative correlation was found between total amount of TI-RADS points and vascular patterns (rs = – 0.238, p = 0.001)
Conclusions: In our study irregular or lobulated margin, taller-than-wide shape and microcalcifications were more common among malignant thyroid nodules. While thyroid US using TI-RADS had good diagnostic value in predicting malignancy, vascular patterns had low sensitivity (40.2%) and specificity (36.7%). Thyroid nodules with intranodular vascularity had a lower TI-RADS score.
Keywords: ultrasound, thyroid, malignancy.