ABSTRACT
Objective To evaluate the value of ultrasound elastography score and strain ratio index in the differential diagnosis of thyroid solid nodules. Methods Eighty-six thyroid solid nodules of 69 patients were divided into 2 groups based on their pathologic results: benign nodules group and malignant nodules group.Compared with pathological results, each thyroid solid nodules' elastographic scores and strain ratio index were respectively analyzed. The sensitivity, specificity and accuracy of elasticity score and strain ratio index were calctlated.The receiver operator characteristic (ROC) curves were drawn according to the results, to choose the best cut-off value.Results There were 67 nodules in benign nodules group and 19 nodules in malignant nodules group. The diameter of benign nodules was (2.05 ± 0.21)cm, malignant nodules was (1.62 ± 0.12)cm. There were no significant differences in the elasticity score and strain ratio index between benign and malignant nodules(t= - 1.736, P ＞ 0.05). Malignant lesions had a higher score and strain ratio index(median 3, 3.97, respectively) than benign ones(median 2, 1.66,respectively, Z = - 5.290, - 5.450, all P ＜ 0.05). If the cut-off value of the elastographic scores was equal or more than 3, the sensitivity, specificity and accuracy were 84.2%(16/19) ,86.6%(58/67) and 86.0%(74/86), respectively,with an area under ROC curve of 0.854. If the cut-off value of the strain ratio index was equal or more than 2.50,the sensitivity, specificity and accuracy were 89.4%(17/19),86.6%(58/67) and 87.2%(75/86), respectively, with an area under ROC curve of 0.911. Conclusion Elasticity score and strain ratio index are helpful in differentiating benign and malignant lesions of thyroid with high clinical value.