Diagnostic Value of Acoustic Radiation Force Impulse Quantification in the Differentiation of Benign and Malignant Thyroid Nodules

The objective of this study was to evaluate the role of ultrasound elastography using acoustic radiation force impulse (ARFI) quantification in characterizing and differentiating malignant versus benign thyroid nodules. A total of 40 thyroid nodules were evaluated with conventional sonography and ultrasound elastography using ARFI quantification. The final diagnosis was obtained from histologic findings. A total of 14 malignant and 26 benign nodules were diagnosed on the basis of histologic examination. Majority of the malignant thyroid nodules demonstrated presence of intranodular vascular flow, hypoechoic echotexture, absent halo, irregular margins and microcalcifications. However, a considerable overlap was noted in the sonographic features of malignant and benign thyroid nodules. On ARFI quantification, the mean shear wave speed (SWS) values (M +/- SD) of malignant and benign thyroid nodules were 3.131 +/- 0.921 m/s and 1.691 +/- 0.513 m/s, respectively. A significant difference was observed between the mean SWS values of malignant thyroid nodules and benign thyroid nodules (p < 0.0001). Applying a cutoff value of 2.53 m/s, the sensitivity, specificity, and the area under the receiver operating characteristic curve for the differentiation were 85.71%, 96.15%, and 0.922, respectively. ARFI quantification is a promising elastography technique that provides quantitative information about tissue stiffness. It provides additional information and complements sonography as an effective diagnostic tool in characterizing and differentiating benign from malignant thyroid nodules.