A comparison of mechanical wave measurement techniques to quantify soft tissue viscoelasticity up to 8 kHz: A phantom study of shear, Rayleigh and Lamb waves

Abstract

Over the past few decades different techniques based on measurement of mechanical wave motion have been developed for noninvasive quantitative measurement and mapping of soft biological tissue shear viscoelastic properties. In this talk we compare two different measurement approaches, three wave types, and several models for quantifying material viscoelasticity up to 8 kHz for a soft tissue phantom material known as ecoflex. Surface waves and Lamb waves are measured using scanning laser Doppler vibrometry (SLDV). Lamb waves and shear waves are measured using magnetic resonance elastography (MRE). Different linear models of viscoelasticity, including Voigt, Maxwell, more generalized and fractional order types, are optimized and compared based on the different experiments. Challenges and limitations of the different techniques and model types, and their adaptation to more complex biological tissue and anatomical structures are discussed. [Work supported by NIH Grants EB012142 and EB007537.]