Frequency-wavenumber domain inversion for arterial viscoelasticity.

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Materials Science

Background:

• Arterial wall viscoelasticity is crucial for cardiovascular health.
• Accurate estimation of these properties aids in diagnosing and managing arterial diseases.
• Current methods for assessing arterial viscoelasticity have limitations in sensitivity and robustness.

Purpose of the Study:

• To develop and validate a novel frequency-wavenumber (f-k) domain inversion approach for estimating arterial wall viscoelastic properties.
• To enhance the sensitivity and robustness of viscoelastic parameter estimation using ultrasound-based shear wave elastography data.
• To compare the performance of the proposed f-k inversion method against existing techniques.

Main Methods:

• Utilized ultrasound-based shear wave elastography data, specifically spatiotemporal arterial wall motion.
• Transformed motion data into the frequency-wavenumber (f-k) domain using a two-dimensional Fast Fourier Transform (2D FFT).
• Estimated viscoelastic properties by maximizing the correlation between measured and simulated f-k motion data derived from a semi-analytical finite element method.

Main Results:

• The f-k inversion method demonstrated higher sensitivity, improved fit, and better conditioning in estimating viscoelastic shear moduli compared to x-t and dispersion-based approaches.
• Achieved high parameter estimation accuracy (within 1.8%) and superior robustness in silico experiments.
• Validated performance advantages in phantom and ex vivo experiments using Voigt and spring-pot viscoelastic models.

Conclusions:

• The proposed f-k inversion method provides accurate and better-conditioned estimates of arterial viscoelastic shear moduli.
• This technique represents a significant methodological advancement for in vivo applications.
• Future work will focus on extensive validation across specimens and independent mechanical testing.