Comparison of ultrasound weighted score and shear wave elastography in differentiating benign and malignant thyroid nodules

Abstract

Objective To evaluate the diagnostic efficacy of shear wave elastography and ultrasound weighted score in differentiating benign and malignant thyroid nodules. Methods Ninety-two patients with 113 thyroid nodules ( 72 benign and 41 malignant) underwent ultrasound weighted score. The items and scores were as follow: hypoechogenicity(2), irregular margin(2), no well-defined border(1), no uniform and complete acoustic halo(1), microcalcification(2), anteroposterior to transverse diameter ratio ≥1 with irregular margin(6), nodules with cystic components which had an diameter larger than 5 mm (-6), posterior enhanced echo(-2), metastasis of neck lymph nodes(6). Shear wave velocity(SWV)of thyroid nodules were measured by virtual touch tissue quantification and the mean SWV of five data was calculated. The diagnostic efficacy of shear wave elastography, ultrasound weighted score, and their combination in differentiating benign and malignant thyroid nodules were calculated by ROC curves. The diagnostic sensitivity, specificity, and accuracy of ultrasound scores, SWV, and their combination in differentiating malignant and benign thyroid nodules were compared. Results The ultrasound score cut-off for the diagnosis of malignant lesions was 4.5 with a sensitivity of 80.5%, specificity of 86.1%, and accuracy of 84.1%. The SWV cut-off for the diagnosis of malignant lesions was 2.55 m/s with a sensitivity of 70.7%, specificity of 88.9%, and accuracy of 82.3%. When two methods were combined, the diagnostic sensitivity, specificity, and accuracy were 95.1%, 80.6% and 85.8%, respectively. Comparing the sensitivity, specificity and accuracy of the three methods, there were no significant difference between any two methods(P>0.016 7), except that the sensitivity of combination was significantly higher than that of SWV (P<0.016 7=. Conclusions Shear wave elastography and ultrasound weighted score both have high value in differentiating benign and malignant thyroid nodules. Combining two methods can not improve diagnosis value comparing with conventional ultrasonography. Key words: Ultrasonography; Thyroid nodules; Elasticity imaging techniques