Correlation between Ultrasonographic Vascular Patterns and Cytological Diagnosis in Thyroid Nodules – A Prospective Study

Open Access

Abstract

Background: Thyroid nodules are frequent clinical findings, and distinguishing benign from malignant lesions remains a diagnostic challenge. Power Doppler Ultrasonography (PDUS) and Duplex Doppler Ultrasonography (DDUS) provide hemodynamic insights that may enhance differentiation. This study evaluated the correlation between Doppler vascular flow patterns and cytological outcomes in thyroid nodules. Methods & Materials: This cross-sectional study included 60 thyroid nodules from 43 patients assessed in the Radiology & Imaging Department of Mymensingh Medical College Hospital from October 2015 to October 2016. Patients with clinically suspected thyroid swelling were referred from ENT outpatient and indoor units. All underwent gray-scale B-mode ultrasonography, PDUS, DDUS with measurement of resistivity and pulsatility indices, and fine-needle aspiration cytology (FNAC) for confirmation. Vascularity was categorized into five patterns: Pattern I (absent flow), Pattern II (perinodular flow), Pattern III (perinodular plus central flow), Pattern IV (central > perinodular flow), and Pattern V (purely central flow). Statistical correlations between Doppler findings and FNAC were analyzed using Fisher’s exact test. Results: The mean patient age was 39.3 ± 14.3 years, with a female predominance. Patterns I–III were found mainly in benign nodules (75.0%, 95.0%, and 88.9%), whereas Patterns IV and V strongly correlated with malignancy (83.3% and 100%; p < 0.001). DDUS classified 65.0% of nodules as benign and 35.0% as malignant based on Doppler indices, showing significant correlation with FNAC (p < 0.001). PDUS demonstrated high diagnostic performance, with 93.8% sensitivity, 88.6% specificity, and 90.0% accuracy. Conclusion: Central or predominantly central vascularity (Patterns IV and V) strongly predicts malignancy. Combined PDUS and DDUS serve as valuable non-invasive adjuncts to FNAC, improving diagnostic confidence and guiding biopsy decisions.