Evaluation of sensitivity of ultrasound imaging biomarkers of cervical viscosity based on shear wave elasticity imaging: A simulation study

Our long-term goal is to quantify changes in the viscoelastic behavior of the uterine cervix during pregnancy using Shear Wave Elasticity Imaging. In this study we compared the sensitivity of two quantitative imaging biomarkers of viscosity extracted from either a time-domain or a frequency-domain analysis of shear wave dispersion. The time-domain descriptor was the ratio R of the group speed obtained from particle velocities and particle displacements. The frequency domain descriptor was the slope S of the phase speed vs. frequency. We observed that R and S are sensitive not only to shear wave dispersion but also to the width and rate of acoustic radiation force impulse (ARFI) excitation. However, S showed the biggest contrast to changes in the tissue viscosity than R, as well as more dependence on the width and pulse duration of the ARFI. Future studies will investigate the tradeoff between contrast and noise.