Shear Wave Elastography in the Diagnosis of Thyroid Nodules with Coexistent Chronic Autoimmune Hashimoto's Thyroiditis

Objective: To evaluate the diagnostic performance of shear wave elastography (SWE) in the differentiation of malignant and benign thyroid nodules with coexistent Hashimoto's thyroiditis (HT).

Study design: Case series with chart review.

Setting: Tertiary general hospital.

Subjects and methods: From September 2012 to January 2014, conventional ultrasound and SWE were performed on 243 patients with 286 thyroid nodules with histologic results. The HT group consisted of 93 patients with 117 nodules. The non-HT group consisted of 140 patients with 169 nodules.

Results: In the benign and malignant nodules, there were no significant differences of the mean, minimum, or maximum SWE values between HT and non-HT groups (P = .158-.945). However, SWE values of extranodular tissue were significantly higher in the HT group (P = .000-.011). In the HT group, the maximum SWE value showed the highest area under the receiver operating characteristic curve (0.817; 95% confidence interval, .735-.900), and there were no significant differences when compared with other SWE parameters (P = .669-.848). In the multivariate analysis, hypoechogenicity (odds ratio = 9.855, P = .002), microcalcification (odds ratio = 3.977, P = .046), and maximum SWE value (odds ratio = 40.712, P < .001) were independent predictors of thyroid malignancy.

Conclusions: SWE could be performed to obtain a differential diagnosis between malignant and benign thyroid nodules, including nodules with coexistent HT. Although all the SWE parameters within a 2-mm region of interest that was placed on the stiffest region could be applied, we suggest that the maximum value of nodules harbored within a Hashimoto's gland be used.