Shear Wave Elastography Combining with Conventional Grey Scale Ultrasound Improves the Diagnostic Accuracy in Differentiating Benign and Malignant Thyroid Nodules

Abstract

Shear wave elastography provides information about the stiffness of thyroid nodules that could be a new indicator of malignancy. The current study aimed to investigate the feasibility of using shear wave elastography (SWE) alone and in conjunction with grey scale ultrasound (GSU) to predict malignancy in 111 solitary thyroid nodules. Malignant thyroid nodules tended to have microcalcification, hypoechogenicity, tall to width ratio >1, and irregular borders (p < 0.05). SWE indices (Emaximum and Emean) of malignant nodules (median ± standard error: 85.2 ± 8.1 kPa and 26.6 ± 2.5 kPa) were significantly higher than those of benign nodules (median ± standard error: 50.3 ± 3.1 kPa and 20.2 ± 1 kPa) (p < 0.05). The optimal cut-off of Emaximum and Emean for distinguishing benign and malignant nodules was 67.3 kPa and 23.1 kPa, respectively. Diagnostic performances for GSU + Emaximum, GSU + Emean, GSU, Emaximum and Emean were: 70.4%, 74.1%, 96.3%, 70.4% and 74.1% for sensitivity, 83.3%, 79.8%, 46.4%, 70.2%, and 66.7% for specificity, and 80.2%, 78.4%, 58.5%, 70.3%, and 68.5% for accuracy, respectively. Our results suggested that combining GSU with SWE (using Emaximum or Emean) increased the overall diagnostic accuracy in distinguishing benign and malignant thyroid nodules.

Keywords

• ultrasound
• thyroid cancer
• shear wave elastography