Thyroid Ultrasound Elasticity (TrUE) Imaging

All ultrasound images will be acquired by an in-house ultrasound technologist using a Verasonics Vantage (Verasonics Inc., Kirkland, Washington, USA) ultrasound system. During imaging, the technologist will position the Verasonics transducer, under b-mode guidance, in planes overlying the thyroid nodules approximating those obtained during previous clinical ultrasound scans.

"Shear wave elasticity imaging (SWEI) is obtained during the standard ultrasound session. The generation of shear wave images consists of two important steps called pushing and tracking. First, in the pushing mode, a long focused ultrasound beam is transmitted to perturb tissue, generating ultrasonic shear waves in tissue that propagate perpendicular to the direction of pushing. In the tracking mode, shear wave propagation is observed and recorded. Because the speed of shear waves is a function of Young's modulus, these data reveal information about the stiffness of underlying biological tissue."

The multi-angle compound SWEI (MAC-SWEI) algorithm, which generates shear images based on multiple angled push beams, has the potential to generate more accurate shear wave images in the context of thyroid imaging. To assess the MAC-SWEI technique, shear wave images will be used to generate estimates of the relative stiffness of lesions via their normalized Young's modulus.