Trans-Skull Volumetric Passive Acoustic Mapping

Overview

Passive acoustic mapping (PAM) is a technique for localizing and quantifying acoustic cavitation — a key bioeffect during focused ultrasound therapy. Extending PAM through the intact human skull to achieve full 3D volumetric imaging had not been experimentally demonstrated prior to this work.

Key Contributions

• Provided the first experimental demonstration of trans-skull volumetric passive acoustic mapping using the Heterogeneous Angular Spectrum Approach (HASA).
• Incorporated CT-derived skull maps to correct for phase aberration and attenuation introduced by heterogeneous bone.
• Achieved accurate 3D localization of cavitation sources through ex vivo human skull specimens.
• Quantified the impact of skull-induced aberrations on image quality and spatial resolution.

Methods & Tools

• Heterogeneous Angular Spectrum (HAS) back-propagation for aberration correction
• Multi-channel passive receive beamforming (Verasonics Vantage)
• CT-based skull bone property estimation
• Angular spectrum delay-and-sum reconstruction
• MATLAB for signal processing and volumetric image reconstruction

Citation

Schoen, S., Dash, P. P., & Arvanitis, C. D. (2021). Experimental demonstration of trans-skull volumetric passive acoustic mapping. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control.