Shear wave elastography for thyroid nodule evaluation in patients with chronic autoimmune thyroiditis

Shear wave elastography (SWE) is a valuable tool in discerning the malignancy risk of thyroid nodules. This study investigates whether 2D-SWE can reliably differentiate malignant thyroid nodules in patients with chronic autoimmune thyroiditis (CAT), despite the challenges posed by fibrosis, which can increase tissue stiffness and complicate diagnosis.

This retrospective observational study evaluated 130 thyroid nodules (91 benign, 39 malignant) in patients with underlying CAT using conventional ultrasound (B-mode) and 2D-SWE with SuperSonic Mach30 equipment (Supersonic Imagine, Aix-en-Provence, France). Pathology reports served as the reference standard.

Out of the 130 nodules, 30% were malignant, and 70% were benign. 2D-SWE proved to be an excellent distinguisher between benign and malignant nodules. Malignant nodules had significantly higher elasticity indices compared to benign nodules (mean elasticity index: 47.2 kPa vs. 18.1 kPa, p < 0.0001; maximum elasticity index: 75 kPa vs. 26.2 kPa, p < 0.0001). The mean elasticity index was the most reliable elastographic parameter (AUC 0.907, sensitivity 87.2% [95% CI: 77.3-94.0%], specificity 84.6% [95% CI: 75.4-91.5%], and NPV 93.9% for a cut-off value of 30.5 kPa).

Our results confirm that 2D-SWE can accurately diagnose malignant thyroid nodules in cases with CAT (p < 0.0001), supporting its use as a complementary tool to conventional ultrasound.