The Diagnostic Performance of Acoustic Radiation Force Impulse Elasticity Imaging to Differentiate Malignant from Benign Thyroid Nodules: Comparison with Conventional B-Mode Sonographic Findings

Purpose The purpose of this study was to evaluate the diagnostic performance of acoustic radiation force impulse (ARFI) elasticity imaging. Materials and Methods One hundred and twenty-seven thyroid nodules were examined by both ARFI elastography and B-mode sonography. Virtual Touch tissue quantification (VTQ) values of the thyroid nodules were measured. Scoring of B-mode sonographic findings of each thyroid nodules was performed. The sums of these VTQ and the B-mode scores were determined. The comparative diagnostic performances of the VTQ value, the B-mode score, and the combined score were analyzed. Results The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of each scoring mode were: B-mode score, 84%, 85%, 66%, 94%, and 85%; VTQ, 75%, 91%, 73%, 92%, and 86%; and combined score, 88%, 87%, 70%, 95%, and 88%. The areas under the curves for B-mode, VTQ, and combined score were 0.895, 0.837, and 0.912, respectively. Pairwise comparisons of receiver-operating characteristic curves showed no statistical differences between B-mode and VTQ, and B-mode and combined score. Combined score showed better diagnostic performance than VTQ value (p = 0.0023). Conclusion ARFI VTQ value is a good diagnostic modality for differentiating malignant thyroid nodules from benign nodules. However, ARFI evaluation is not superior to B-mode sonographic evaluation, but only has a better diagnostic performance when combined with B-mode sonographic findings.