To date the fine needle aspiration (FNA) is the main diagnostic test to assess the malignancy of a thyroid nodule. However it is inconclusive when the diagnosis is follicular variant.
Objective: to distinguish thyroid nodules in benign or malignant by power and Duplex-Doppler US comparing the data with the anatopathological evaluation.
Methods: 40 patients (5 men, 35 women; mean age 47) presenting 53 thyroid nodules have been evaluated by power and Duplex-Doppler US, employing a predicting malignancy score with parameters such as echogenicity (hipoechoic or not), size, presence of microcalcification, resistance index (RI) and a vascularization pattern (I, absence of signal blood flow; II, exclusively perinodular blood flow; III, perinodular blood flow higher or equal to central blood flow; IV, marked central blood flow and less significant perinodular blood flow; V, exclusively central blood flow). The score results were compared to histological diagnosis.
Results: Thirteen nodules from 53 (24,5%) were confirmed malignant by the histology. The hipoecogenicity (Sensitivity = 84,6%), microcalcification (Sensitivity = 61,5%) and the vascularization pattern (Sensitivity = 69,2%) were the best parameters to identify the malignat nodules. On the other side, color Doppler (Specificity of 90,0%) and the RI (Specifity of 87,5%) were the best patterns to predict benignity. The best RI cut-off would be 0,70 (Sensitivity of 69%; specificity of 75%). Multivariate analysis including the IV/ V patterns,the hipoechogenicity and the RI >0,75 showed sensitivity of 61,5% end specificity of 97,5%.
Conclusion: The best malignity predictive values are vascularization patterns IV or V, RI >0,75 and hipoechogenicity.