Ultrasound Elastography for Distinction Between Parathyroid Adenomas and Thyroid Nodules

Objectives-The aim of this study was to detect the level of stiffness of parathyroid adenomas and to distinguish them from benign and malignant thyroid nodules using ultrasound elastography with acoustic radiation force impulse imaging. Methods-Twenty-one patients with parathyroid adenomas and 71 patients with thyroid nodules were evaluated by acoustic radiation force impulse imaging in this study. Acoustic radiation force impulse elastograms were obtained after evaluation of the thyroid nodules, which were predicted to undergo fine-needle aspiration biopsy, and patients with a diagnosis of hyperparathyroidism, which was identified by sonography at the same time. Results-An analysis of mean shear wave velocity (SWV) values for parathyroid adenomas and thyroid nodules showed that parathyroid adenomas had significantly higher stiffness levels compared to benign thyroid nodules (mean SWV +/- SD, 3.09 +/- 0.75 versus 2.20 +/- 0.39 m/s; P < .001) and lower stiffness levels compared to malignant thyroid nodules (mean SWV, 3.09 +/- 0.75 versus 3.59 +/- 0.43 m/s; P < .001). Conclusions-Acoustic radiation force impulse imaging has high sensitivity and specificity for differentiating parathyroid adenomas from benign and malignant thyroid nodules. As an adjunctive tool, it can help distinguish parathyroid adenomas from thyroid nodules, including posteriorly located nodules.