The research team (PI and Sponsor) have agreed that this study would not be feasible to continue.

Our overall hypothesis is that Contrast-enhanced ultrasound (CEUS) and Shear Wave Elastography (SWE) will allow for high diagnostic accuracy of benign and malignant thyroid nodules, which will correlate with and complement the ACR TI-RADS classification system, allowing for more accurate diagnosis of benign and malignant thyroid nodules.

Thyroid nodules are an exceedingly common clinical entity, however, only a small percentage of nodules are malignant. Conventional ultrasound is the current standard for the initial evaluation of thyroid nodules, yet due to several overlapping characteristics between benign and malignant nodules its utility in diagnosis has been limited, leading to a high rate of negative biopsies. To overcome these challenges the American College of Radiology has proposed a Thyroid Imaging Reporting and Data System (TI-RADS) in an effort to decrease unnecessary biopsies [5]. While these efforts have shown encouraging results, further work is still needed. Contrast-enhanced ultrasound (CEUS) and Shear Wave Elastography (SWE) are two emerging non-invasive imaging techniques which have shown promising results in the evaluation of thyroid nodules. However, data is limited and how these imaging modalities could potentially compliment ACR TI-RADS is unknown.

Inclusion Criteria:

• - Patients over the age of 18 with one or more thyroid nodules diagnosed on conventional ultrasound within the last 6 months.
• Patients referred for standard of care thyroid nodule biopsy, ordered at the discretion of the treating physician and/or radiologists.
• Patients must demonstrate ability to understand and express willingness to sign a written informed consent to undergo SWE and CEUS imaging prior to their thyroid nodule biopsy.

Exclusion Criteria:

• Patients who are pregnant, nursing, or less than 18 years of age
• Thyroid nodules ≤1 cm