TY - GEN
T1 - Modal analysis on arteries and tubes using ultrasound vibrometry
AU - Bernal, Miguel
AU - Urban, Matthew W.
AU - Greenleaf, James F.
PY - 2010
Y1 - 2010
N2 - Introduction. Arterial elasticity has been proposed as an independent predictor of cardiovascular diseases and mortality. Measurement of the wave speed dispersion for different modes of propagation in thin shells can be used to estimate elastic properties of these structures. Using ultrasound radiation force, it is possible to generate local shear waves which can be tracked with pulse-echo ultrasound to measure their speed of propagation. In the present work, we present a modal analysis performed on an elastic tube and an excised pig carotid artery that can be use to estimate the elastic properties. Methods. A urethane tube and an excised artery were mounted in a metallic frame, cannulated and embedded in tissue-mimicking gelatin. Shear waves were generated in the wall of the tube/artery using a 3 MHz confocal transducer with a 200 μs toneburst epeated at a rate of 50 Hz. The propagation was measured using pulse-echo ultrasound at 21 locations along the vessel wall spaced 1 mm apart. The transmural pressure was varied from 10 to 100 mmHg in 10 mmHg increments using a column of water. Results. The group velocity of the shear wave for the tube and the artery were significantly different, around 11 m/s for the tube and 5 m/s for the artery. The speed of propagation in the tube showed no variation with increasing tranmural pressure, while in the group velocity of the artery increased from 4 m/s at 10 mmHg to 6.2 m/s at 100 mmHg. The modal analysis using a 2D FFT of the spatio-temporal signal in the tube showed a unique antisymmetric Lamb wave-like mode that was almost invariant with pressure. Meanwhile, the artery exhibited multiple modes, antisymmetric and symmetric like modes, that varied with pressure. Conclusion. Radiation force is a useful technique to generate localized shear waves in cylindrical shell structures. The changes in the observed dispersion curves in the arteries are very encouraging, suggesting that this methodology has potential use in the study of arterial elasticity.
AB - Introduction. Arterial elasticity has been proposed as an independent predictor of cardiovascular diseases and mortality. Measurement of the wave speed dispersion for different modes of propagation in thin shells can be used to estimate elastic properties of these structures. Using ultrasound radiation force, it is possible to generate local shear waves which can be tracked with pulse-echo ultrasound to measure their speed of propagation. In the present work, we present a modal analysis performed on an elastic tube and an excised pig carotid artery that can be use to estimate the elastic properties. Methods. A urethane tube and an excised artery were mounted in a metallic frame, cannulated and embedded in tissue-mimicking gelatin. Shear waves were generated in the wall of the tube/artery using a 3 MHz confocal transducer with a 200 μs toneburst epeated at a rate of 50 Hz. The propagation was measured using pulse-echo ultrasound at 21 locations along the vessel wall spaced 1 mm apart. The transmural pressure was varied from 10 to 100 mmHg in 10 mmHg increments using a column of water. Results. The group velocity of the shear wave for the tube and the artery were significantly different, around 11 m/s for the tube and 5 m/s for the artery. The speed of propagation in the tube showed no variation with increasing tranmural pressure, while in the group velocity of the artery increased from 4 m/s at 10 mmHg to 6.2 m/s at 100 mmHg. The modal analysis using a 2D FFT of the spatio-temporal signal in the tube showed a unique antisymmetric Lamb wave-like mode that was almost invariant with pressure. Meanwhile, the artery exhibited multiple modes, antisymmetric and symmetric like modes, that varied with pressure. Conclusion. Radiation force is a useful technique to generate localized shear waves in cylindrical shell structures. The changes in the observed dispersion curves in the arteries are very encouraging, suggesting that this methodology has potential use in the study of arterial elasticity.
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M3 - Conference contribution
AN - SCOPUS:84869104978
SN - 9781617827457
T3 - 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society
SP - 4110
EP - 4113
BT - 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating Proceedings of the 2010 Annual Conference of the Australian Acoustical Society
T2 - 20th International Congress on Acoustics 2010, ICA 2010 - Incorporating the 2010 Annual Conference of the Australian Acoustical Society
Y2 - 23 August 2010 through 27 August 2010
ER -