Real-time Ultrasound Elastography in the Differential Diagnosis of Benign and Malignant Thyroid Nodules

Objective. The purpose of this study was to evaluate the diagnostic utility of real-time ultrasound elastography in differentiating benign from malignant thyroid nodules. Methods. A total of 90 consecutive patients with thyroid nodules who were referred for surgical treatment were examined in this prospective study. One hundred forty-five nodules in these patients were examined by B-mode ultrasound, color Doppler ultrasound, and ultrasound elastography. The final diagnosis was obtained from histologic findings, Tissue stiffness on ultrasound elastography was scored from 1 (low stiffness over the entire nodule) to 6 (high stiffness over the entire nodule and surrounding tissue). Results. On real-time ultrasound elastography, 86 of 96 benign nodules (90%) had a score of I to 3, whereas 43 of 49 malignant nodules (88%) had a score of 4 to 6 (P < .001), with sensitivity of 88%, specificity of 90%, a positive predictive value of 81%, and a negative predictive value of 93%. The predictivity of ultrasound elastographic measurement was independent of the nodule size. High sensitivity (88%) and specificity (93%) were also observed in 68 nodules that had a greatest diameter of 1 cm or less. Conclusions. Real-time ultrasound elastography is a promising imaging technique that is useful in the differential diagnosis of thyroid cancer.