Diagnostic Value of Elastography for Thyroid Nodules in Hashimoto's Thyroiditis

Objective To evaluate the diagnostic performance of elastography in the diagnosis of thyroid nodules in the context of Hashimoto's thyroiditis(HT). Methods The study evaluated 43 thyroid nodules by conventional ultrasound (CU) and elastography in 38 patients co-existed with HT who were referred for operation. The patients underwent CU and elastography before operation. The sensitivity,specificity,positive and negative predictive values,and accuracy for CU,elastography,and combination of these two techniques were assessed by using histopathological results as the gold standard. Results Among these 43 thyroid nodules,pathology confirmed 29 (67.4%) malignant nodules and 14 (32.6%) benign ones. There were statistically significant differences between malignant and benign groups in features such as solid shape (96.6% vs. 64.0%;OR:15.6,95%CI:1.600-151.262,P=0.004),irregularity (90.0% vs. 42.9%;OR:11.6,95%CI:2.341-57.032,P=0.001),taller than wide shape (72.0% vs. 21.4%;OR:9.6,95% CI:2.117-43.753,P=0.002),microcalcification (69% vs. 28.6%;OR:5.6,95% CI:1.368-22.556,P=0.012) and irregular blood flow (90.0% vs. 28.6%;OR:17.3,95%CI:3.186-94.290,P=0.000). The diagnostic performance of elastography and CU was as follows:sensitivity (86.2 % vs.96.6%),specificity (71.4% vs.42.9%),positive predictive value (86.2% vs.77.8%),negative predictive value (71.4% vs.85.7%),and accuracy (81.4% vs.79.0%). The combination of these two techniques had a sensitivity of 93.1%,a specificity of 71.4%,a positive predictive value of 87.1%,a negative predictive value of 83.3%,and an accuracy of 86.0%. Conclusions Elastography has a higher specificity in the diagnosis of thyroid nodules in HT,while its sensitivity is slightly lower than that of CU. Combination of these two techniques can increase the specificity and accuracy.