Anisotropic conductivity imaging with MREIT using equipotential projection algorithm

Eyüboğlu, Behçet Murat
Magnetic resonance electrical impedance tomography (MREIT) combines magnetic flux or current density measurements obtained by magnetic resonance imaging (MRI) and surface potential measurements to reconstruct images of true conductivity with high spatial resolution. Most of the biological tissues have anisotropic conductivity; therefore, anisotropy should be taken into account in conductivity image reconstruction. Almost all of the MREIT reconstruction algorithms proposed to date assume isotropic conductivity distribution. In this study, a novel MREIT image reconstruction algorithm is proposed to image anisotropic conductivity. Relative anisotropic conductivity values are reconstructed iteratively, using only current density measurements without any potential measurement. In order to obtain true conductivity values, only either one potential or conductivity measurement is sufficient to determine a scaling factor. The proposed technique is evaluated on simulated data for isotropic and anisotropic conductivity distributions, with and without measurement noise. Simulation results show that the images of both anisotropic and isotropic conductivity distributions can be reconstructed successfully.


Experimental results for 2D magnetic resonance electrical impedance tomography (MR-EIT) using magnetic flux density in one direction
Birgul, O; Eyüboğlu, Behçet Murat; Ider, YZ (IOP Publishing, 2003-11-07)
Magnetic resonance electrical impedance tomography (MR-EIT) is an emerging imaging technique that reconstructs conductivity images using magnetic flux density measurements acquired employing MRI together with conventional EIT measurements. In this study, experimental MR-EIT images from phantoms with conducting and insulator objects are presented. The technique is implemented using the 0.15 T Middle East Technical University MRI system. The dc current method used in magnetic resonance current density imaging...
Current constrained voltage scaled reconstruction (CCVSR) algorithm for MR-EIT and its performance with different probing current patterns
Birgul, O; Eyüboğlu, Behçet Murat; Ider, YZ (IOP Publishing, 2003-03-07)
Conventional injected-current electrical impedance tomography (EIT) and magnetic resonance imaging (MRI) techniques can be combined to reconstruct high resolution true conductivity images. The magnetic flux density distribution generated by the internal current density distribution is extracted from MR phase images. This information is used to form a fine detailed conductivity image using an Ohm's law based update equation. The reconstructed conductivity image is assumed to differ from the true image by a s...
Distinguishability for magnetic resonance-electrical impedance tomography (MR-EIT)
Altunel, Haluk; Eyüboğlu, Behçet Murat; Koksal, Adnan (IOP Publishing, 2007-01-21)
A distinguishability measure is defined for magnetic resonance-electrical impedance tomography (MR-EIT) based on magnetic flux density measurements. This general definition is valid for 2D and 3D structures of any shape. As a specific case, a 2D cylindrical body with concentric inhomogeneity is considered and a bound of the distinguishability is analytically formulated. Distinguishabilities obtained with potential and magnetic flux density measurements are compared.
Two-dimensional multi-frequency imaging of a tumor inclusion in a homogeneous breast phantom using the harmonic motion Doppler imaging method
TAFRESHI, Azadeh Kamali; TOP, Can Baris; Gençer, Nevzat Güneri (IOP Publishing, 2017-06-21)
Harmonic motion microwave Doppler imaging (HMMDI) is a novel imaging modality for imaging the coupled electrical and mechanical properties of body tissues. In this paper, we used two experimental systems with different receiver configurations to obtain HMMDI images from tissue-mimicking phantoms at multiple vibration frequencies between 15 Hz and 35 Hz. In the first system, we used a spectrum analyzer to obtain the Doppler data in the frequency domain, while in the second one, we used a homodyne receiver th...
Anisotropic conductivity imaging with MREIT using equipotential projection algorithm
DEĞİRMENCİ, EVREN; Eyüboğlu, Behçet Murat (2007-09-02)
Magnetic resonance electrical impedance tomography (MREIT) is a new medical imaging technique which combines boundary potential measurements of electrical impedance tomography (EIT) and internal current density distribution obtained from magnetic resonance imaging (MRI) to produce conductivity images having high spatial resolution and accuracy. In this study, a novel method of reconstructing images of anisotropic conductivity tensor distribution inside an electrically conducting subject is proposed for MREI...
Citation Formats
E. DEĞİRMENCİ and B. M. Eyüboğlu, “Anisotropic conductivity imaging with MREIT using equipotential projection algorithm,” PHYSICS IN MEDICINE AND BIOLOGY, pp. 7229–7242, 2007, Accessed: 00, 2020. [Online]. Available: