Biomedical Applications of Vibration and Acoustics in Imaging and Characterizations
12 Characterization of Tissue Viscoelasticity from Shear Wave Speed Dispersion
Download citation file:
- Ris (Zotero)
- Reference Manager
Quantitative measurement of tissue elasticity and viscosity has important medical applications because pathologies are often linked to abnormal tissue mechanical properties. Shearwave Dispersion Ultrasound Vibrometry (SDUV) is proposed to quantify tissue viscoelasticity. SDUV uses a focused ultrasound beam within FDA safety limits to stimulate formation and propagation of harmonic shear waves in the studied tissue. The propagation speed of induced shear wave is frequency-dependent (dispersive) and relates to the tissue's mechanical properties. Shear wave speeds at a number of frequencies are measured by pulse-echo ultrasound setup and fit with a theoretical dispersion model to inversely solve for tissue elasticity and viscosity. A special pulse sequence is developed to make SDUV compatible with commercial ultrasound scanners. In vitro SDUV measurements in gelatin phantom, liver, and pork and beef muscle show promising results, demonstrating the feasibility of SDUV to quantify tissue elasticity and viscosity.