Single Probe Enabled Refraction-Corrected Transcranial Passive Acoustic Mapping Through Macaque Calvaria.

Area of Science:

• Biomedical Engineering
• Acoustics
• Neuroscience

Background:

• Accurate transcranial passive acoustic mapping (TPAM) for microbubble (MB) cavitation requires skull sound speed correction.
• Current CT-based methods are complex, costly, and prone to registration errors.

Purpose of the Study:

• To develop a low-cost, all-ultrasound method for refraction-corrected TPAM.
• To improve the accuracy of transcranial acoustic source localization.

Main Methods:

• Utilized the head wave technique to reconstruct a multi-layer skull sound speed map (SSM).
• Employed the heterogeneous angular spectrum approach for passive acoustic mapping (PAM).
• Validated in vitro using hydrophone and MB cavitation experiments on macaque calvariae.

Main Results:

• Achieved sub-millimeter source localization error with the proposed method (F-number < 1.2).
• Reduced localization error by 1.8-5.9 times compared to uncorrected methods.
• Demonstrated comparable performance to CT-corrected methods.

Conclusions:

• The all-ultrasound method offers a cost-effective solution for monitoring transcranial MB cavitation.
• This technique could advance the study of MB-mediated focused therapies in the brain.
• Further clinical translation studies are warranted.