Comparison of shear velocity dispersion in viscoelastic phantoms measured by ultrasound-based shear wave elastography and magnetic resonance elastography

Pathological processes in soft tissues cause changes in mechanical properties. Elastography methods have emerged to make quantitative measurements of the shear modulus or shear wave speed (SWS) as a noninvasive way to provide diagnostic information. In an effort to standardize ultrasound-based measurements of SWS, the Radiological Society of North America Quantitative Imaging Biomarkers Alliance (RSNA QIBA) has established working groups to develop profiles for different biomarkers including the use of SWS for staging of patients with liver fibrosis. To understand how ultrasound-based measurements vary with tissue viscoelasticity, measurements were made in viscoelastic phantoms with ultrasound-based shear wave elastography (US-SWE) and magnetic resonance elastography (MRE) over a wide frequency range.