Phantom experiment and clinical utility of quantitative shear wave elastography for differentiating thyroid nodules

Area of Science:

• Medical Imaging
• Diagnostic Ultrasound
• Elastography

Background:

• Shear wave elastography (SWE) using acoustic radiation force impulse (ARFI) is an emerging ultrasonography technique.
• Accurate differentiation of thyroid nodules is crucial for appropriate patient management.

Purpose of the Study:

• To evaluate the clinical usefulness of quantitative SWE in distinguishing between benign and malignant thyroid nodules.
• To assess the correlation between shear wave velocity (SWV) and nodule characteristics.

Main Methods:

• A phantom study measured SWVs of spheres with varying hardness.
• A clinical study measured SWVs in 112 thyroid nodules (84 benign, 28 papillary carcinoma) and 94 normal thyroid glands.
• SWVs were compared between normal thyroid tissue, benign nodules, and malignant nodules.

Main Results:

• Phantom study: SWVs correlated with hardness for 2-cm spheres but not 1-cm spheres.
• Clinical study: Mean SWVs were 1.64 m/s (normal), 1.88 m/s (benign), and 2.67 m/s (papillary carcinoma).
• Papillary carcinomas had significantly higher SWVs than benign nodules (P < 0.001), with an ROC AUC of 0.809.

Conclusions:

• Quantitative SWE provides valuable information on thyroid nodule characteristics, specifically tissue stiffness.
• SWE demonstrates potential as a non-invasive tool for differentiating malignant thyroid nodules.
• Larger nodules may yield more stable SWV measurements.