TY - GEN
T1 - In vivo measurements of viscoelasticity of the swine heart using Shearwave Dispersionc Ultrasound Vibrometry (SDUV)
AU - Urban, Matthew W.
AU - Pislaru, Cristina
AU - Kinnick, Randall R.
AU - Greenleaf, James F.
PY - 2010
Y1 - 2010
N2 - Quantification of the viscoelastic properties of the myocardium using ultrasound may aid with evaluation of the health of the heart. Shearwave Dispersion Ultrasound Vibrometry (SDUV) is a method that uses dispersion, or variation with frequency, of shear wave velocities to characterize the underlying viscoelastic material properties of soft tissue. We studied eight pigs in an open-chest preparation, using a mechanical actuator to create harmonic, propagating mechanical waves in the myocardial wall. The motion was tracked using a high frame rate acquisition sequence, typically 2500 Hz, with a Sonix RP system. The velocities of wave propagation were measured over the range 50-350 Hz in 50 Hz increments. Data were acquired over several cardiac cycles. Dispersion curves were fit with a viscoelastic, asymmetrical Lamb wave model to obtain estimates of the shear elasticity, 1, and viscosity, 2. We found excellent agreement between the elastic term measured by SDUV and the shear elastic modulus measured by pressure-segment length analysis. We demonstrated that SDUV measurements and Lamb wave theory allow us to estimate the variation of viscoelastic moduli of the myocardial walls in vivo throughout the course of the cardiac cycle.
AB - Quantification of the viscoelastic properties of the myocardium using ultrasound may aid with evaluation of the health of the heart. Shearwave Dispersion Ultrasound Vibrometry (SDUV) is a method that uses dispersion, or variation with frequency, of shear wave velocities to characterize the underlying viscoelastic material properties of soft tissue. We studied eight pigs in an open-chest preparation, using a mechanical actuator to create harmonic, propagating mechanical waves in the myocardial wall. The motion was tracked using a high frame rate acquisition sequence, typically 2500 Hz, with a Sonix RP system. The velocities of wave propagation were measured over the range 50-350 Hz in 50 Hz increments. Data were acquired over several cardiac cycles. Dispersion curves were fit with a viscoelastic, asymmetrical Lamb wave model to obtain estimates of the shear elasticity, 1, and viscosity, 2. We found excellent agreement between the elastic term measured by SDUV and the shear elastic modulus measured by pressure-segment length analysis. We demonstrated that SDUV measurements and Lamb wave theory allow us to estimate the variation of viscoelastic moduli of the myocardial walls in vivo throughout the course of the cardiac cycle.
KW - Lamb waves
KW - heart
KW - shear waves
KW - viscoelasticity
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U2 - 10.1109/ULTSYM.2010.5935764
DO - 10.1109/ULTSYM.2010.5935764
M3 - Conference contribution
AN - SCOPUS:80054724949
SN - 9781457703829
T3 - Proceedings - IEEE Ultrasonics Symposium
SP - 686
EP - 689
BT - 2010 IEEE International Ultrasonics Symposium, IUS 2010
T2 - 2010 IEEE International Ultrasonics Symposium, IUS 2010
Y2 - 11 October 2010 through 14 October 2010
ER -