ACTA ENDOCRINOLOGICA (BUC)

Background. Thyroid nodules stiffness may predict thyroid malignancy. Objectives. The purpose of the study was to investigate the diagnostic value, interobserver agreement and reliability of real time ultrasound elastography (USE) when assessing solid thyroid nodules. Design. A prospective, observational study in a tertiary center. Subjects and Methods. In 49 patients scheduled for thyroidectomy, a senior radiologist and two radiologists in training independently assessed 81 solid thyroid nodules with USE using a 6600 Hitachi machine. Pathology results were used as a reference standard. Nodule stiffness was evaluated using the Asteria scoring system. The diagnostic ability of the elastography scores for the assessment of the thyroid solid nodules was evaluated using AUROC (area under the receiver operating characteristic curve) analysis. The Cohen’s kappa (k) values were used for interobserver agreement evaluation and interclass correlation coefficient (ICC) was used as a measure of reliability. Results. Pathology results revealed 20 papillary carcinomas and 61 benign nodules. The elastography identification of malignant nodules by the senior radiologist was performed with an AUROC of 0.84 [95% Confidence interval (CI) 0.74-0.91], with Sensitivity= 100%, and Specificity= 68.85%. When performed by ultrasound operators in training, the diagnostic performance slightly decreased. With no statistically significant difference between the diagnostic performance of the three readers, USE demonstrated good inter-observer agreement and good reliability (ICC= 0.81). Conclusion. USE may be an accurate tool of assessment for solid thyroid nodules, identifying with high sensitivity the malignant ones, particularly micronodules. USE is reproducible and reliable when used both by experienced operators and medical professionals in training.