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Sensitivity analysis of magnetic field measurements for magnetic resonance electrical impedance tomography (MREIT)

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@article{5244c5619a7d4857933eb6c5c7d53784,
title = "Sensitivity analysis of magnetic field measurements for magnetic resonance electrical impedance tomography (MREIT)",
abstract = "PURPOSE: Clinical use of magnetic resonance electrical impedance tomography (MREIT) still requires significant sensitivity improvements. Here, the measurement of the current-induced magnetic field (ΔBz,c ) is improved using systematic efficiency analyses and optimization of multi-echo spin echo (MESE) and steady-state free precession free induction decay (SSFP-FID) sequences.THEORY AND METHODS: Considering T1 , T2 , and T2* relaxation in the signal-to-noise ratios (SNRs) of the MR magnitude images, the efficiency of MESE and SSFP-FID MREIT experiments, and its dependence on the sequence parameters, are analytically analyzed and simulated. The theoretical results are experimentally validated in a saline-filled homogenous spherical phantom with relaxation parameters similar to brain tissue. Measurement of ΔBz,c is also performed in a cylindrical phantom with saline and chicken meat.RESULTS: The efficiency simulations and experimental results are in good agreement. When using optimal parameters, ΔBz,c can be reliably measured in the phantom even at injected current strengths of 1 mA or lower for both sequence types. The importance of using proper crusher gradient selection on the phase evolution in a MESE experiment is also demonstrated.CONCLUSION: The efficiencies observed with the optimized sequence parameters will likely render in-vivo human brain MREIT feasible. Magn Reson Med, 2017. {\circledC} 2017 International Society for Magnetic Resonance in Medicine.",
keywords = "Journal Article",
author = "Cihan G{\"o}ksu and Klaus Scheffler and Philipp Ehses and Hanson, {Lars G} and Axel Thielscher",
note = "{\circledC} 2017 International Society for Magnetic Resonance in Medicine.",
year = "2018",
month = "2",
doi = "10.1002/mrm.26727",
language = "English",
volume = "79",
pages = "748--760",
journal = "Magnetic Resonance in Medicine",
issn = "0740-3194",
publisher = "John/Wiley & Sons, Inc. John/Wiley & Sons Ltd",

}

RIS

TY - JOUR

T1 - Sensitivity analysis of magnetic field measurements for magnetic resonance electrical impedance tomography (MREIT)

AU - Göksu, Cihan

AU - Scheffler, Klaus

AU - Ehses, Philipp

AU - Hanson, Lars G

AU - Thielscher, Axel

N1 - © 2017 International Society for Magnetic Resonance in Medicine.

PY - 2018/2

Y1 - 2018/2

N2 - PURPOSE: Clinical use of magnetic resonance electrical impedance tomography (MREIT) still requires significant sensitivity improvements. Here, the measurement of the current-induced magnetic field (ΔBz,c ) is improved using systematic efficiency analyses and optimization of multi-echo spin echo (MESE) and steady-state free precession free induction decay (SSFP-FID) sequences.THEORY AND METHODS: Considering T1 , T2 , and T2* relaxation in the signal-to-noise ratios (SNRs) of the MR magnitude images, the efficiency of MESE and SSFP-FID MREIT experiments, and its dependence on the sequence parameters, are analytically analyzed and simulated. The theoretical results are experimentally validated in a saline-filled homogenous spherical phantom with relaxation parameters similar to brain tissue. Measurement of ΔBz,c is also performed in a cylindrical phantom with saline and chicken meat.RESULTS: The efficiency simulations and experimental results are in good agreement. When using optimal parameters, ΔBz,c can be reliably measured in the phantom even at injected current strengths of 1 mA or lower for both sequence types. The importance of using proper crusher gradient selection on the phase evolution in a MESE experiment is also demonstrated.CONCLUSION: The efficiencies observed with the optimized sequence parameters will likely render in-vivo human brain MREIT feasible. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

AB - PURPOSE: Clinical use of magnetic resonance electrical impedance tomography (MREIT) still requires significant sensitivity improvements. Here, the measurement of the current-induced magnetic field (ΔBz,c ) is improved using systematic efficiency analyses and optimization of multi-echo spin echo (MESE) and steady-state free precession free induction decay (SSFP-FID) sequences.THEORY AND METHODS: Considering T1 , T2 , and T2* relaxation in the signal-to-noise ratios (SNRs) of the MR magnitude images, the efficiency of MESE and SSFP-FID MREIT experiments, and its dependence on the sequence parameters, are analytically analyzed and simulated. The theoretical results are experimentally validated in a saline-filled homogenous spherical phantom with relaxation parameters similar to brain tissue. Measurement of ΔBz,c is also performed in a cylindrical phantom with saline and chicken meat.RESULTS: The efficiency simulations and experimental results are in good agreement. When using optimal parameters, ΔBz,c can be reliably measured in the phantom even at injected current strengths of 1 mA or lower for both sequence types. The importance of using proper crusher gradient selection on the phase evolution in a MESE experiment is also demonstrated.CONCLUSION: The efficiencies observed with the optimized sequence parameters will likely render in-vivo human brain MREIT feasible. Magn Reson Med, 2017. © 2017 International Society for Magnetic Resonance in Medicine.

KW - Journal Article

U2 - 10.1002/mrm.26727

DO - 10.1002/mrm.26727

M3 - Journal article

VL - 79

SP - 748

EP - 760

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

SN - 0740-3194

ER -

ID: 50574142