On multiple alternating steady states induced by periodic spin phase perturbation waveforms.

Area of Science:

• Neuroimaging
• Magnetic Resonance Imaging (MRI)
• Biophysics

Background:

• Direct measurement of neural currents using MRI offers high temporal and spatial resolution for monitoring neuronal activity.
• Previous methods like alternating balanced steady state imaging show sensitivity to weak periodic currents but require precise synchronization.

Purpose of the Study:

• To extend alternating balanced steady state imaging to a multiple balanced alternating steady states technique.
• To enable the estimation of neural current waveforms using MRI.

Main Methods:

• Development and application of the multiple balanced alternating steady states technique.
• Utilizing simulations and phantom experiments to validate the method.
• Analyzing the off-resonance profile of the signal for frequency content information.

Main Results:

• The off-resonance profile of the multiple alternating steady state signal contains information about the frequency content of driving waveforms.
• The new technique demonstrates reduced sensitivity to precise waveform timing relative to radiofrequency pulses compared to previous methods.

Conclusions:

• The multiple alternating steady state technique is a promising advancement for MR imaging of neural current waveforms.
• This method holds potential for non-invasive monitoring of periodic neuronal activity dynamics.