Meeting Banner
Abstract #4332

MRI measurements of field modulations: Extended frequency range of spin-lock preparation with off-resonance pulses

Fróði Gregersen1,2, Axel Thielscher1,2, and Lars Hanson1,2
1Section for Magnetic Resonance, DTU Health Tech, Technical University of Denmark, Copenhagen, Denmark, 2Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital - Amager and Hvidovre, Copenhagen, Denmark

Synopsis

Keywords: Signal Modeling, New Signal Preparation Schemes

Motivation: Mapping current flow during temporal interference stimulation (kHz range) or the application of tumor treating fields (100 kHz - 300 kHz) can improve target localization and dose control for these techniques.

Goal(s): Explore novel encoding strategies to measure high-frequency magnetic field modulations caused by injected currents.

Approach: We use Bloch simulations to explore novel encoding strategies and phantom measurements with currents that create magnetic fields modulations for validation.

Results: We show that with off-resonance preparation pulses it is possible to be sensitive to high frequency field modulations while avoiding SAR and B1 limits, albeit with a lower sensitivity than previously suggested spin-lock methods.

Impact: This work demonstrates the possibility of measuring time-varying fields at a much greater frequency range than previously possible, which can be crucial for high-frequency brain stimulation techniques such as temporal interference stimulation and tumor treating fields.

How to access this content:

For one year after publication, abstracts and videos are only open to registrants of this annual meeting. Registrants should use their existing login information. Non-registrant access can be purchased via the ISMRM E-Library.

After one year, current ISMRM & ISMRT members get free access to both the abstracts and videos. Non-members and non-registrants must purchase access via the ISMRM E-Library.

After two years, the meeting proceedings (abstracts) are opened to the public and require no login information. Videos remain behind password for access by members, registrants and E-Library customers.

Click here for more information on becoming a member.

Keywords

frequencyfieldfieldsstimulation