The diagnostic value of elastography score and strain index for the evaluation of thyroid micronodules.

Background/aim: In the general population, the frequency of thyroid micronodules is increasing, and the prevalence of malignancy is higher for such nodules. Ultrasonography findings of these nodules are neither specific nor sensitive. The aim of this study was to investigate the diagnostic value of elastography in patients with thyroid micronodules. Materials and methods: A total of 224 patients with thyroid micronodules were recruited in this prospective study. All patients underwent a thyroid fine-needle aspiration biopsy. Elastography scores (ESs) and strain indexes (SIs) were measured with real-time ultrasound elastography. Results: Malignant micronodules had higher ES and SI values than those of benign micronodules (P < 0.001). When ES was used to diagnose malignancy, scores of >3 showed sensitivity of 79.4% and specificity of 98.1%. The area under the curve (AUC) for ES was 0.888 (P < 0.001). The optimal SI cutoff value that differentiated benign from malignant micronodules was 3.06 (98% sensitivity; 91% specificity). The AUC for SI was 0.970 (P < 0.001). Conclusions: ES and SI are beneficial markers for detecting malignant thyroid micronodules. We showed that SI is better than ES when assessing the malignancy of thyroid micronodules.