Axial anisotropic conductivity imaging based on projected current density in MREIT

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electrical Engineering

Background:

• Magnetic Resonance Electrical Impedance Tomography (MREIT) aims to visualize internal current density and conductivity.
• Current MREIT methods ideally utilize a single component of magnetic flux density (B) for imaging.
• Object rotation is often undesirable in MREIT measurements.

Purpose of the Study:

• To present a novel MREIT method for visualizing the axial anisotropic conductivity tensor.
• To achieve this using only the B(z) component of magnetic flux density, measured without object rotation.
• To recover individual conductivity tensor components from measured B(z) data.

Main Methods:

• Developed a method utilizing projected current density derived from measured B(z) data.
• Employed a matching process between measured B(z) data, projected currents, and an intermediate isotropic conductivity.
• Validated the algorithm using numerical simulations and a postmortem canine brain case.

Main Results:

• Numerical simulations demonstrated the algorithm's robustness to noise and stable determination of anisotropic conductivity.
• The method successfully visualized anisotropic conductivity components in a canine brain sample.
• Reconstructed images accurately reflected the anisotropic properties of white matter, aligned with fiber direction.

Conclusions:

• The proposed MREIT method enables visualization of axial anisotropic conductivity tensors.
• The technique is stable, robust to noise, and applicable to biological tissues.
• This advancement has potential implications for understanding tissue properties in neuroimaging and other applications.