Abstract: Objective To investigate the diagnostic value of acoustic radiation force impulse imaging（ARFI） in differentiating solid malignant and benign thyroid nodules. Methods A total of 68 patients（99 nodules） who underwent thyroid nodule resection were selected from June 2015 to September 2016 in the First Affiliated Hospital of Henan University of Science and Technology. All these imaging data were analyzed retrospectively. ARFI were performed in all patients before operation， and the shear wave velocity （SWV） of ARFI were observed and recorded. Pathological examination was considered as gold standard， the differences between benign and malignant nodules and the surrounding normal thyroid tissue were analyzed using the independent sample t test. The cut-off point of the SWV value of thyroid benign nodules was obtained by using the receiver operating characteristic curve （ROC）. The sensitivity， specificity， accuracy， positive predictive value and negative predictive value of ARFI technique in the diagnosis of benign and malignant nodular thyroid lesions were analyzed. Results The SWV of benign nodules， malignant nodules and the surrounding normal thyroid tissue were （2.68±0.51）m／s， （3.09±0.53）m／s and （2.42±0.22）m／s. The SWV of malignant nodules were higher than the benign thyroid nodules，and the SWV of benign and malignant nodules were higher than the surrounding normal thyroid tissue， the above differences were statistically significant（P＜0.001）. The SWV ratio of malignant nodule and surrounding normal thyroid tissues were 1.277±0.258， higher than 1.108±0.205 of benign nodule and surrounding normal thyroid tissues， and the difference was statistically significant（P＜0.001）. The sensitivity， specificity， accuracy， positive predictive value and negative predictive value of SWV value and SWV ratio in the diagnosis of thyroid lesions were 63.41％， 74.14％， 69.70％， 63.41％， 74.14％ and 58.54％， 79.31％， 69.70％， 64.86％，72.58％ respectively. Conclusion As a noninvasive technique，ARFI is of high value in differenting benign and malignant thyroid nodules. It can be widely used in clinical diagnosis.

Key words: Thyroid nodules, Acoustic radiation force impulse imaging （ARFI）, Differential diagnosis