Anisotropic conductivity imaging with MREIT using equipotential projection algorithm

Değirmenci, Evren; Eyüboğlu, B. Murat

doi:10.1088/0031-9155/52/24/003

Cited by 24 publications

(13 citation statements)

References 26 publications

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“…The current density depends on the actual pathways of current flow inside the brain, and shows their values when current flows are parallel to fiber direction. [23][24][25][26] CSF showed highest values due to its inherent high conductivity of 2.0 S/m. The current density of gray matter was lowest, because it consists of numerous cell bodies and relatively few myelinated axons.…”

Section: Discussionmentioning

confidence: 99%

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

Sajib

Kim

et al. 2017

AIP Advances

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New methods for in vivo mapping of brain responses during deep brain stimulation (DBS) are indispensable to secure clinical applications. Assessment of current density distribution, induced by internally injected currents, may provide an alternative method for understanding the therapeutic effects of electrical stimulation. The current flow and pathway are affected by internal conductivity, and can be imaged using magnetic resonance-based conductivity imaging methods. Magnetic resonance electrical impedance tomography (MREIT) is an imaging method that can enable highly resolved mapping of electromagnetic tissue properties such as current density and conductivity of living tissues. In the current study, we experimentally imaged current density distribution of in vivo canine brains by applying MREIT to electrical stimulation. The current density maps of three canine brains were calculated from the measured magnetic flux density data. The absolute current density values of brain tissues, including gray matter, white matter, and cerebrospinal fluid were compared to assess the active regions during DBS. The resulting current density in different tissue types may provide useful information about current pathways and volume activation for adjusting surgical planning and understanding the therapeutic effects of DBS.

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Section: Discussionmentioning

confidence: 99%

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

Sajib

Kim

et al. 2017

AIP Advances

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“…It is well known that brain white matter has strong anisotropic characteristics, because it consists of numerous nerve bundles with inherent directional information. 4,5 The electrical tissue conductivity relies on the actual pathways of current flow inside the brain, [24][25][26][27] and shows more enhanced conductivity than its actual value. This clear contrast originates because the current density of the anisotropic model represents a more realistic distribution, combining the assigned conductivity and actual current flows from the DTI information.…”

Section: Quantitative Analysismentioning

confidence: 99%

Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

Jeong

Sajib

et al. 2015

AIP Advances

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Electromagnetic fields provide fundamental data for the imaging of electrical tissue properties, such as conductivity and permittivity, in recent magnetic resonance (MR)-based tissue property mapping. The induced voltage, current density, and magnetic flux density caused by externally injected current are critical factors for determining the image quality of electrical tissue conductivity. As a useful tool to identify bio-electromagnetic phenomena, precise approaches are required to understand the exact responses inside the human body subject to an injected currents. In this study, we provide the numerical simulation results of electromagnetic field mapping of brain tissues using a MR-based conductivity imaging method. First, we implemented a realistic three-dimensional human anisotropic head model using high-resolution anatomical and diffusion tensor MR images. The voltage, current density, and magnetic flux density of brain tissues were imaged by injecting 1 mA of current through pairs of electrodes on the surface of our head model. The current density map of anisotropic brain tissues was calculated from the measured magnetic flux density based on the linear relationship between the water diffusion tensor and the electrical conductivity tensor. Comparing the current density to the previous isotropic model, the anisotropic model clearly showed the differences between the brain tissues. This originates from the enhanced signals by the inherent conductivity contrast as well as the actual tissue condition resulting from the injected currents.

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“…This leads to choosing the regularization parameter which minimizes the function (9) The second step of the MDEIT image reconstruction is reconstructing the conductivity distribution from the current density image produced by the last step. Many image reconstruction algorithms using internal current density distribution have been proposed for MREIT, for example, integration along equipotential lines [21], [22], the equipotential-projection algorithm [23], [24], the current constrained voltage scaled reconstruction (CCVSR) algorithm [25] and the -substitution algorithm [26]- [31].…”

Section: B Inverse Problem In Mdeitmentioning

confidence: 99%

A New Electrode Mode for Magnetic Detection Electrical Impedance Tomography: Computer Simulation Study

Hao

Chen

2012

IEEE Trans. Magn.

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The authors propose a new electrode mode for magnetic detection electrical impedance tomography (MDEIT). MDEIT is a new EIT imaging technique that aims to reconstruct the conductivity distribution using the external magnetic flux density. Based on the forward solver and image reconstruction algorithms, the feasibility of a new electrode mode, called annular electrode mode, is tested. The simulation experiments' results show that this electrode mode can produce a similar effect with the longitudinal current, making the direction current density image on the plane consistent with the corresponding conductivity image. With the electrode mode, we can infer the conductivity distribution from the current density image. Consequently, MDEIT can be simplified to magnetic detection current density imaging (MDCDI) shortening the data measurement time and image reconstruction time and making a step towards developing MDEIT as a rapid imaging technique.Index Terms-Annular electrode mode, current density imaging, inverse problem, magnetic detection electrical impedance tomography.

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Anisotropic conductivity imaging with MREIT using equipotential projection algorithm

Cited by 24 publications

References 26 publications

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

In vivo mapping of current density distribution in brain tissues during deep brain stimulation (DBS)

Evaluation of three-dimensional anisotropic head model for mapping realistic electromagnetic fields of brain tissues

A New Electrode Mode for Magnetic Detection Electrical Impedance Tomography: Computer Simulation Study

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