TY - JOUR
T1 - Time-Aligned Plane Wave Compounding Methods for High-Frame-Rate Shear Wave Elastography
T2 - Experimental Validation and Performance Assessment on Tissue Phantoms
AU - Capriotti, Margherita
AU - Greenleaf, James F.
AU - Urban, Matthew W.
N1 - Publisher Copyright:
© 2021 The Authors
PY - 2021/7
Y1 - 2021/7
N2 - Shear wave elastography (SWE) is an ultrasonic technique able to quantitatively assess the mechanical properties of tissues by combining acoustic radiation force and ultrafast imaging. While utilizing coherent plane wave compounding enhances echo and shear wave motion signal-to-noise ratio (SNR), it also reduces the effective pulse repetition frequency (PRFe), affecting the accuracy of the measurements of motion and, consequently, of material properties. It is important to maintain both high-motion SNR and PRFe, particularly for the characterization of (material and/or geometrical) dispersive tissues such as arteries. This work proposes a method for SWE measurements with high SNR, while maintaining a high PRFe, using conventional clinical ultrasound scanners. A time alignment process is applied after acquiring data from plane wave transmissions at different angles. The time alignment uses interpolation to obtain data points at higher frame rates, and the time-aligned data are compounded to increase the SNR. The method is used for SWE in tissue-mimicking phantoms of different stiffness and is compared with traditional plane wave compounding. Increases of 58% and 36% in spatial and temporal bandwidth compared with conventional plane wave compounding, respectively, can be achieved for SWE measurements of representative arterial stiffness values. Improvements in phase velocity accuracy and bandwidth in an arterial phantom are also described, to emphasize the beneficial advantage in dispersive cases.
AB - Shear wave elastography (SWE) is an ultrasonic technique able to quantitatively assess the mechanical properties of tissues by combining acoustic radiation force and ultrafast imaging. While utilizing coherent plane wave compounding enhances echo and shear wave motion signal-to-noise ratio (SNR), it also reduces the effective pulse repetition frequency (PRFe), affecting the accuracy of the measurements of motion and, consequently, of material properties. It is important to maintain both high-motion SNR and PRFe, particularly for the characterization of (material and/or geometrical) dispersive tissues such as arteries. This work proposes a method for SWE measurements with high SNR, while maintaining a high PRFe, using conventional clinical ultrasound scanners. A time alignment process is applied after acquiring data from plane wave transmissions at different angles. The time alignment uses interpolation to obtain data points at higher frame rates, and the time-aligned data are compounded to increase the SNR. The method is used for SWE in tissue-mimicking phantoms of different stiffness and is compared with traditional plane wave compounding. Increases of 58% and 36% in spatial and temporal bandwidth compared with conventional plane wave compounding, respectively, can be achieved for SWE measurements of representative arterial stiffness values. Improvements in phase velocity accuracy and bandwidth in an arterial phantom are also described, to emphasize the beneficial advantage in dispersive cases.
KW - Group velocity
KW - Phase velocity
KW - Plane wave compounding
KW - Shear wave
KW - Time aligned
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U2 - 10.1016/j.ultrasmedbio.2021.03.003
DO - 10.1016/j.ultrasmedbio.2021.03.003
M3 - Article
C2 - 33863605
AN - SCOPUS:85104490130
SN - 0301-5629
VL - 47
SP - 1931
EP - 1948
JO - Ultrasound in Medicine and Biology
JF - Ultrasound in Medicine and Biology
IS - 7
ER -