title: Current density imaging using directly measured harmonic Bz data in MREIT.
abstract: Magnetic resonance electrical impedance tomography (MREIT) measures magnetic flux density signals through the use of a magnetic resonance imaging (MRI) in order to visualize the internal conductivity and/or current density. Understanding the reconstruction procedure for the internal current density, we directly measure the second derivative of Bz data from the measured k-space data, from which we can avoid a tedious phase unwrapping to obtain the phase signal of Bz . We determine optimal weighting factors to combine the derivatives of magnetic flux density data, [Symbol: see text](2) Bz , measured using the multi-echo train. The proposed method reconstructs the internal current density using the relationships between the induced internal current and the measured [Symbol: see text](2) Bz data. Results from a phantom experiment demonstrate that the proposed method reduces the scanning time and provides the internal current density, while suppressing the background field inhomogeneity. To implement the real experiment, we use a phantom with a saline solution including a balloon, which excludes other artifacts by any concentration gradient in the phantom.
authors.affiliation: Department of Mathematics, Konkuk University, Seoul 143-701, Republic of Korea.
authors.forename: Chunjae
authors.initials: C
authors.lastname: Park
authors.forename: Oh In
authors.initials: OI
authors.lastname: Kwon
mesh_terms: D000465:Algorithms; D019295:Computational Biology / Q000379:methods; D004553:Electric Conductivity; D017097:Electric Impedance; D004566:Electrodes; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008280:Magnetics; D015233:Models, Statistical; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012984:Software; D014054:Tomography / Q000379:methods*