Diagnostic value of ultrasound elastography and conventional ultrasound for thyroid nodules: a meta-analysis

Background: Thyroid nodular disease is a common disorder. Ultrasonography has emerged as a powerful tool for the diagnosis of thyroid disease owing to its high operational simplicity, non-invasiveness and reproducibility. This study aimed to systematically evaluate the value of ultrasound elastography and conventional ultrasound for the diagnosis of thyroid nodules.Methods: The PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure, Wanfang and VIP databases were searched systematically. RevMan 5.3 software was used to draw a risk bias map, and Stata 16.0 was used to plot a sensitivity and specificity forest map. A summary receiver operating characteristics (SROC) curve was plotted, and the area under the curve (AUC) was calculated. Meta-regression was used to explore the sources of heterogeneity.Results: The sensitivity of conventional ultrasonography for detecting thyroid nodules was 0.55 [95% confidence interval (CI): 0.45-0.65], the specificity was 0.90 (95% CI: 0.87-0.93), the positive likelihood ratio was 5.8 (95% CI: 3.8-8.9), the negative likelihood ratio was 0.49 (95% CI: 0.39-0.6), and the AUC was 0.86 (95% CI: 0.82-0.88). The sensitivity of ultrasonic elastography for detecting thyroid nodules was 0.67 (95% CI: 0.60-0.73), the specificity was 0.93 (95% CI: 0.90-0.95), the positive likelihood ratio was 9.1 (95% CI: 6.3-13.3), the negative likelihood ratio was 0.36 (95% CI: 0.29-0.44), and the AUC was 0.89 (95% CI: 0.86-0.91). The sensitivity of conventional ultrasound combined with ultrasonic elastography for detecting thyroid nodules was 0.88 (95% CI: 0.84-0.90), the specificity of the combined approach was 0.96 (95% CI: 0.93-0.98), the positive likelihood ratio was 23.3 (95% CI: 12.4-43.6), the negative likelihood ratio was 0.13 (95% CI: 0.10-0.17), and the AUC was 0.92 (95% CI: 0.90-0.94). Age, region, research type, conventional ultrasound evaluation criteria and elastography evaluation criteria had specific effects on sensitivity and specificity when detecting thyroid nodules.Conclusions: Conventional ultrasound can be used as a routine examination technique for the differential diagnosis of benign and malignant thyroid nodules, while ultrasound elastography can improve the sensitivity and specificity of the diagnosis. The diagnostic value of conventional ultrasound combined with ultrasound elastography is higher than that of a single diagnostic method.