A novel bounded EIT protocol to generate inhomogeneous skull conductivity maps non-invasively

Area of Science:

• Biomedical Engineering
• Medical Imaging
• Electrical Engineering

Background:

• Parametric Electrical Impedance Tomography (bEIT) estimates head tissue conductivity using standard "1-to-1" current patterns.
• Current "1-to-1" bEIT methods struggle to provide localized skull conductivity estimates, often modeling tissues as homogeneous.
• Skull tissues are known to be inhomogeneous within individuals, impacting the accuracy of current models.

Purpose of the Study:

• To develop and validate a novel "1-to-N" current injection pattern for bEIT.
• To generate individual and spatially resolved skull conductivity maps.
• To improve the accuracy of head models for neuroimaging and stimulation applications.

Main Methods:

• Proposed a new bEIT protocol utilizing "1-to-N" current injection patterns with one source and multiple sinks.
• Applied the novel protocol to build inhomogeneous skull conductivity maps.
• Validated the method through simulations and compared results with traditional "1-to-1" patterns.

Main Results:

• The "1-to-N" bEIT protocol successfully generated individual skull conductivity maps.
• Simulations demonstrated that the novel method's maps exhibit better spatial correlation with spongy bone distribution compared to "1-to-1" methods.
• The new protocol provides spatially resolved skull conductivity data.

Conclusions:

• The novel "1-to-N" bEIT protocol enables non-invasive, in vivo mapping of individual head models with spatially resolved skull conductivities.
• This advancement is crucial for enhancing electroencephalography (EEG) source localization and transcranial electrical stimulation (TES) applications.
• The method offers a safer alternative to CT scans for detailed head modeling.