Diagnostic Utility of Gray Scale Ultrasound and Elastography in Solitary Thyroid

Abstract

Background: A firm and hard thyroid nodule on palpation is associated with an increased risk of malignancy .Palpation is subjective. Elastography has been introduced to evaluate the tissue hardness objectively and to augment the diagnostic accuracy of gray-scale ultrasonography (US). Aim and objectives: To evaluate the diagnostic utility of gray-scale ultrasonography (US) and elastography in differentiating benign and malignant thyroid nodules. Materials and methods: A retrospective analysis of Gray scale US and Elastography of 70 solid thyroid nodules in 50 patients was done in our Dhiraj General Hospital over a 6 month period. Diagnostic performances of gray scale US, Elastography with Rago and Asteria criteria, and Odd’s ratios (ORs) with 95% confidence intervals for predicting thyroid malignancy were compared with gold standard FNAC using generalized estimating equation. Results: 70 solid thyroid nodules in 50 patients were evaluated. 21 were malignant and 49 were benign. Sensitivity, negative predictive value (NPV), and Odd’s ratio(OR) of gray-scale US for the 70 nodules were 91.6%, 94.5% and 22.2 respectively, and these values were higher than the 15.6% and 65.3% sensitivity, 71.6% and 79.2% NPV and 3.6 and 2.7 ORs found for elastography with Rago and Asteria criteria, respectively. Conclusion: Elastography alone as well as the combination of elastography and gray-scale US showed inferior performance in the differentiation of malignant and benign thyroid nodules compared with gray-scale US features. Hence elastography is not a useful tool in recommending FNAC.