Progress in Phased-Array Mechanical Drivers for Magnetic Resonance Elastography
Mariappan Y, Glaser K, Ehman R
Mayo Clinic college of Medicine
Dynamic MR Elastography measures the stiffness of tissues by imaging propagating shear waves. Typical low frequency (50200 Hz) shear waves induced in the sample (via transverse or longitudinal drivers) have limitations like high attenuation, shallow wave penetration or low resolution. We investigated a high frequency mode conversion technique wherein high frequency longitudinal waves are induced and stiff regions are detected by imaging the shear waves that are present only in these regions, the waves are highly attenuated in the soft regions. The short wavelength of these high frequency waves will allow for more accurate stiffness measurements of stiff regions.