title: Noise analysis in magnetic resonance electrical impedance tomography at 3 and 11 T field strengths.
abstract: In magnetic resonance electrical impedance tomography (MREIT), we measure the induced magnetic flux density inside an object subject to an externally injected current. This magnetic flux density is contaminated with noise, which ultimately limits the quality of reconstructed conductivity and current density images. By analysing and experimentally verifying the amount of noise in images gathered from two MREIT systems, we found that a carefully designed MREIT study will be able to reduce noise levels below 0.25 and 0.05 nT at main magnetic field strengths of 3 and 11 T, respectively, at a voxel size of 3 x 3 x 3 mm(3). Further noise level reductions can be achieved by optimizing MREIT pulse sequences and using signal averaging. We suggest two different methods to estimate magnetic flux noise levels, and the results are compared to validate the experimental setup of an MREIT system.
authors.affiliation: Department of Biomedical Engineering, University of Florida, Gainesville, USA.
authors.forename: Rosalind
authors.initials: R
authors.lastname: Sadleir
authors.forename: Samuel
authors.initials: S
authors.lastname: Grant
authors.forename: Sung Uk
authors.initials: SU
authors.lastname: Zhang
authors.forename: Byung Il
authors.initials: BI
authors.lastname: Lee
authors.forename: Hyun Chan
authors.initials: HC
authors.lastname: Pyo
authors.forename: Suk Hoon
authors.initials: SH
authors.lastname: Oh
authors.forename: Chunjae
authors.initials: C
authors.lastname: Park
authors.forename: Eung Je
authors.initials: EJ
authors.lastname: Woo
authors.forename: Soo Yeol
authors.initials: SY
authors.lastname: Lee
authors.forename: Ohin
authors.initials: O
authors.lastname: Kwon
authors.forename: Jin Keun
authors.initials: JK
authors.lastname: Seo
mesh_terms: D017097:Electric Impedance; D006801:Humans; D008279:Magnetic Resonance Imaging; D009622:Noise; D014054:Tomography