Wavefield-Aware quality control and shear wave speed estimation in ocular Vibro-Elastography

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Ophthalmology

Background:

• Complex wavefield phenomena in ocular tissues challenge accurate shear wave speed (SWS) analysis.
• Ultrasound Vibro-Elastography (UVE) is a promising technique for assessing tissue biomechanics.
• Developing robust UVE methods is crucial for analyzing intraocular lesions.

Purpose of the Study:

• To investigate wavefield complexity in confined ocular structures.
• To develop and validate a wavefield-aware framework for UVE analysis.
• To differentiate intraocular lesions based on biomechanical properties.

Main Methods:

• Evaluated wavefield-aware UVE using simulations, phantoms, and patient data.
• Compared spectral k-ω, phase-gradient (DPG/TPI), and local phase velocity imaging with wavefield-based filtering (LPVI-WBF) methods.
• Implemented wavefield quality control (QC) and multifrequency analysis (100-200 Hz).

Main Results:

• k-ω and DPG/TPI methods showed sensitivity to wave reflections and interference, yielding unstable SWS estimates.
• Wavefield-based QC with LPVI-WBF provided stable SWS mapping in intraocular lesion regions.
• Melanoma lesions exhibited significantly stronger dispersion slopes and higher frequency-domain heterogeneity than nevus lesions.

Conclusions:

• Wavefield-aware UVE analysis offers sensitive biomarkers for lesion differentiation.
• Dispersion curve strength and inter-frequency heterogeneity effectively distinguish melanoma from nevus.
• Absolute SWS alone is insufficient for differentiating these intraocular lesions.