Mobile human brain imaging using functional ultrasound.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Studying the human brain in naturalistic settings is challenging with current neuroimaging methods.
• Mobile neuroimaging techniques are needed to overcome the limitations of traditional, stationary scanners.
• Functional ultrasound imaging (fUSi) offers a promising avenue for real-time brain activity monitoring.

Purpose of the Study:

• To demonstrate the feasibility of real-time functional ultrasound imaging (fUSi) during natural behaviors, specifically walking.
• To validate fUSi signals obtained during locomotion against established neuroimaging techniques.
• To assess the long-term stability and reliability of fUSi in a subject with a skull implant.

Main Methods:

• Utilized a clinically approved sonolucent skull implant for ultrafast ultrasound access.
• Employed personalized 3D-printed helmets for stable fUSi probe placement during movement.
• Integrated optical tracking for cross-modal validation with functional magnetic resonance imaging (fMRI) and facial tracking for behavioral paradigms.
• Applied advanced signal processing to extract hemodynamic responses from fUSi data.

Main Results:

• Achieved consistent and reliable fUSi signals from brain activity over a 20-month period.
• Demonstrated successful real-time fUSi monitoring during high-motion activities, including walking.
• Validated fUSi findings through cross-modal comparisons with fMRI and behavioral tracking.

Conclusions:

• Real-time fUSi is a feasible mobile neuroimaging technique for studying brain activity during natural behaviors.
• The developed approach, combining specialized hardware and advanced processing, enables robust brain monitoring in real-world scenarios.
• This advancement represents a significant step towards leveraging fUSi for both clinical applications and fundamental neuroscience research.