Improved Shear Wave Group Velocity Estimation Method Based on Spatiotemporal Peak and Thresholding Motion Search

Abstract

Quantitative ultrasound elastography is increasingly being used in the assessment of chronic liver disease. Many studies have reported ranges of liver shear wave velocities values for healthy individuals and patients with different stages of liver fibrosis. Nonetheless, ongoing efforts exist to stabilize quantitative ultrasound elastography measurements by assessing factors that influence tissue shear wave velocity values, such as food intake, body mass index (BMI), ultrasound scanners, scanning protocols, ultrasound image quality, etc. Time-to-peak (TTP) methods have been routinely used to measure the shear wave velocity. However, there is still a need for methods that can provide robust shear wave velocity estimation in the presence of noisy motion data. The conventional TTP algorithm is limited to searching for the maximum motion in time profiles at different spatial locations. In this study, two modified shear wave speed estimation algorithms are proposed. The first method searches for the maximum motion in both space and time (spatiotemporal peak, STP); the second method applies an amplitude filter (spatiotemporal thresholding, STTH) to select points with motion amplitude higher than a threshold for shear wave group velocity estimation. The two proposed methods (STP and STTH) showed higher precision in shear wave velocity estimates compared to TTP in phantom. Moreover, in a cohort of 14 healthy subjects STP and STTH methods improved both the shear wave velocity measurement precision and the success rate of the measurement compared to conventional TTP.

Local Phase Velocity Based Imaging: A New Technique Used for Ultrasound Shear Wave Elastography

“…Most of the methods are based on time-domain data and measuring the timeof-flight of the shear wave in a local sense. Different features of the shear wave motion are used for estimation of the shear wave velocity including the peaks of the displacement or velocity waveforms [14]- [16]. Additionally, cross-correlation of time signals is used [2], [3], [17] and the size of the window used can affect the shear wave velocity results [15].…”

Multiparametric in vivo ultrasound shear wave viscoelastography on farm-raised fatty duck livers: human radiology imaging applied to food sciences

“…Ultrasound elastography has provided important datasets on human liver fibrosis and steatosis ( Deffieux et al., 2015 ; Nightingale et al., 2015 ; Loomba, 2018 ; Parker et al., 2018 ). Typically, SW elastography is used to assess the shear wave speed ( SWS ) or Young's modulus as a measure of liver stiffness ( Osaki et al., 2010 ; Ferraiolli et al., 2014 ; Yoon et al., 2014 ; Franchi-Abella et al., 2016 ; Song et al., 2016 ; Carrascal et al., 2017 ; Palmeri, 2019 ). Recent attention has also been given to SW attenuation as a measure of acoustic energy dispersion characteristics of a tissue ( Bernard et al., 2016 ; Nenadic et al., 2017 ; Sharma et al., 2019 ).…”

Evaluation of Formalin Fixation for Tissue Biopsies Using Shear Wave Laser Speckle Imaging System

“…Time to peak (TTP) cross-correlation method is the most common approach with shear wave elasticity imaging [40]. We implemented the TTP method with multiple improvements to suppress very strong noise in laser speckle images from unevenly-accumulated laser scattering, sample inhomogeneity, viscoelasticity, and external vibrations.…”