Quantitative evaluation of contrast-enhanced ultrasound after intravenous administration of a microbubble contrast agent for differentiation of benign and malignant thyroid nodules: assessment of diagnostic accuracy

Objectives To investigate the diagnostic accuracy, through quantitative analysis, of contrast-enhanced ultrasound (CEUS), using a microbubble contrast agent, in the differentiation of thyroid nodules. Methods This prospective study enrolled 46 patients with solitary, scintigraphically non-functional thyroid nodules. These patients were scheduled for surgery and underwent preoperative CEUS with pulse-inversion harmonic imaging after intravenous microbubble contrast medium administration. Using histology as a standard of reference, time-intensity curves of benign and malignant nodules were compared by means of peak enhancement and wash-out enhancement relative to the baseline intensity using a mixed model ANOVA. ROC analysis was performed to assess the diagnostic accuracy in the differentiation of benign and malignant nodules on CEUS. Results The complete CEUS data of 42 patients (31/42 [73.8%] benign and 11/42 [26.2%] malignant nodules) revealed a significant difference ( < 0.001) in enhancement between benign and malignant nodules. Furthermore, based on ROC analysis, CEUS demonstrated sensitivity of 76.9%, specificity of 84.8% and accuracy of 82.6%. Conclusions Quantitative analysis of CEUS using a microbubble contrast agent allows the differentiation of benign and malignant thyroid nodules and may potentially serve, in addition to grey-scale and Doppler ultrasound, as an adjunctive tool in the assessment of patients with thyroid nodules. Key Points Contrast-enhanced ultrasound (CEUS) helps differentiate between benign and malignant thyroid nodules. Quantitative CEUS analysis yields sensitivity of 76.9% and specificity of 84.8%. CEUS may be a potentially useful adjunct in assessing thyroid nodules.