The Role of various Ultrasound parameters in the evaluation of Thyroid lesions and its correlation with Thyroid Cytopathology

Objective : The objective of this study was to evaluate the diagnostic accuracy of various ultrasound parameters in the diagnosis of malignant thyroid nodules and to correlate ultrasonographic findings with cytological diagnosis as reference.Material & Methods:  In this prospective study a total of  165 patients attending the surgery/ENT OPD with complaints of thyroid swelling were included. On Ultrasonography the nodules were assessed on the basis of composition , echogenecity, margins , calcification , internal vascularity and presence of any associated lymphadenopathy. Sensitivity, Specificity and diagnostic accuracy of each individual US parameter was calculated . The results were then compared with cytological diagnosis.Results: The incidence of malignancy in our study was 6.66% (11/165). Of all the ultrasound characteristics, a predominantly solid composition, presence of fine calcifications and irregular borders had high sensitivity but low specificity for the diagnosis of malignancy.On the other hand, presence of internal vascularity within the nodule had the highest specificity and overall diagnostic accuracy. The sensitivity ,specificity and overall diagnostic accuracy of Ultrasound for characterising a malignant nodule was found to be 78.5% , 99.3% and 97.57% respectively.Conclusion : Ultrasonography along with FNAC is useful in the initial evaluation of thyroid nodules .While histopathology remains the gold standard for establishing the final diagnosis, attention to specific ultrasound patterns appear to be useful indicators in suspicious nodules which in turn may avoid unnecessary surgical intervention in benign nodules.