Anisotropic conductivity imaging with MREIT using equipotential projection algorithm

Phys Med Biol. 2007 Dec 21;52(24):7229-42. doi: 10.1088/0031-9155/52/24/003. Epub 2007 Nov 23.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Anisotropy*
  • Artifacts
  • Computer Simulation
  • Electric Conductivity*
  • Electric Impedance*
  • Image Enhancement / methods
  • Image Interpretation, Computer-Assisted / methods
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*
  • Models, Biological
  • Radiometry / methods
  • Sensitivity and Specificity