Model-Free Measurement of Shear Wave Velocity and Attenuation From K-Space

Technology #2012-221

Ultrasound radiation force is used to create propagating waves in soft tissue or other soft materials. The wave propagation is measured using pulse-echo ultrasound methods. We use a two-dimensional Fourier transform method to obtain the Fourier-space (k-space) with the coordinates of frequency (f) and wave number (k). The wave velocity © at each frequency is calculated by finding the k-space peak at the given frequency and noting that c=f/k. The wave attenuation at each frequency is calculated by measuring the full-width-half-maximum (FWHM) of the peak at the given frequency. This approach allows us to calculate both the velocity and attenuation of the wave at each frequency and thus obtain model-free (true to nature) storage and loss moduli of the tissue.