Abstract

Background: Grayscale ultrasound (US) is the most common imaging modality for the assessment of thyroid nodules. Objective: This research aimed to assess the value of using the elasticity index (EI), obtained using shear wave elastography (SWE), to discriminate between malignant and benign thyroid nodules. Materials and methods: A total of 86 patients (94 distinct thyroid nodules) were operated on at Vietnam National Cancer Hospital from June 2018 to June 2019. Comparisons of the grayscale ultrasound (US) findings and the EI values between the benign and malignant groups were performed using the Chi-square test and Student’s t-test, respectively. The discrimination abilities of EI were determined through receiver operating characteristic (ROC) curve analysis, with the computation of optimal cut-off points. Results: The EI values of the benign and malignant groups were 37.6 ± 26.1 kPa and 105.4 ± 48.8 kPa, respectively. The area under the ROC curve (AUROC) value for discrimination between groups based on EI values was 0.889 when using an optimal cut-off point of 74.5 kPa, which resulted in a sensitivity of 74.3% and a specificity of 90%. Logistic multivariate regression analysis found that EI and microcalcification were significant factors for the discrimination between groups, with an odds ratio (OR): 1.487 [95% confidence interval (95% CI): 1.124–1.968, p = 0.005] and OR: 12.119 (95% CI: 2.031–72.323, p = 0.006), respectively. Combining grayscale US imaging with SWE can increase the specificity of the diagnosis but does not increase the accuracy. Conclusion: SWE can be helpful for predicting the malignancy of thyroid nodules, although the accuracy of this method is only moderate.

Key words: shear wave elastography, thyroid nodule, malignancy, elasticity index.