Electric Current Detection Based on the MR Signal Magnitude Decay

Area of Science:

• Magnetic Resonance Imaging
• Biophysics
• Medical Imaging Technology

Background:

• Conventional current density imaging relies on detecting induced magnetic fields, which is technically demanding.
• A simpler, more accessible method for current detection in imaging is needed.

Purpose of the Study:

• To propose and evaluate a novel signal-magnitude-decay (SMD)-based method for current density detection.
• To compare the SMD method with conventional techniques in terms of simplicity and applicability.

Main Methods:

• Imaged conductive and biological samples using gradient- or spin-echo sequences with superimposed currents.
• Sampled the SMD curve for each voxel to enable voxel-wise current density calculation.
• Investigated the effect of voxel size and acquisition time on signal decay and calculation precision.

Main Results:

• Current flow induces an inhomogeneous magnetic field, leading to faster signal decay.
• Estimated current density using SMD correlated well with actual values, particularly with larger voxels and longer acquisition times.
• The SMD method demonstrated comparable sensitivity to conventional methods.

Conclusions:

• The SMD method provides a simpler and more versatile approach to current density detection.
• This technique is not limited by sample orientation or geometry, expanding its potential use in various imaging scenarios, including in vivo studies.