Current-induced alternating reversed dual-echo-steady-state for joint estimation of tissue relaxation and electrical properties

Hyunyeol Lee, Chul Ho Sohn, Jaeseok Park

Research output: Contribution to journalArticle

Abstract

Purpose: To develop a current-induced, alternating reversed dual-echo-steady-state-based magnetic resonance electrical impedance tomography for joint estimation of tissue relaxation and electrical properties. Methods: The proposed method reverses the readout gradient configuration of conventional, in which steady-state-free-precession (SSFP)-ECHO is produced earlier than SSFP-free-induction-decay (FID) while alternating current pulses are applied in between the two SSFPs to secure high sensitivity of SSFP-FID to injection current. Additionally, alternating reversed dual-echo-steady-state signals are modulated by employing variable flip angles over two orthogonal injections of current pulses. Ratiometric signal models are analytically constructed, from which T1, T2, and current-induced Bz are jointly estimated by solving a nonlinear inverse problem for conductivity reconstruction. Numerical simulations and experimental studies are performed to investigate the feasibility of the proposed method in estimating relaxation parameters and conductivity. Results: The proposed method, if compared with conventional magnetic resonance electrical impedance tomography, enables rapid data acquisition and simultaneous estimation of T1, T2, and current-induced Bz, yielding a comparable level of signal-to-noise ratio in the parameter estimates while retaining a relative conductivity contrast. Conclusion: We successfully demonstrated the feasibility of the proposed method in jointly estimating tissue relaxation parameters as well as conductivity distributions. It can be a promising, rapid imaging strategy for quantitative conductivity estimation.

Original languageEnglish
JournalMagnetic Resonance in Medicine
DOIs
Publication statusAccepted/In press - 2016

Fingerprint

Joints
Electric Impedance
Magnetic Resonance Spectroscopy
Tomography
Injections
Signal-To-Noise Ratio

Keywords

  • Alternating steady-state-free-precession
  • Conductivity
  • Dual-echo-steady-state
  • Magnetic resonance imaging
  • Relaxation

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

Cite this

@article{2abb7259ac0141ef9382092182a69cde,
title = "Current-induced alternating reversed dual-echo-steady-state for joint estimation of tissue relaxation and electrical properties",
abstract = "Purpose: To develop a current-induced, alternating reversed dual-echo-steady-state-based magnetic resonance electrical impedance tomography for joint estimation of tissue relaxation and electrical properties. Methods: The proposed method reverses the readout gradient configuration of conventional, in which steady-state-free-precession (SSFP)-ECHO is produced earlier than SSFP-free-induction-decay (FID) while alternating current pulses are applied in between the two SSFPs to secure high sensitivity of SSFP-FID to injection current. Additionally, alternating reversed dual-echo-steady-state signals are modulated by employing variable flip angles over two orthogonal injections of current pulses. Ratiometric signal models are analytically constructed, from which T1, T2, and current-induced Bz are jointly estimated by solving a nonlinear inverse problem for conductivity reconstruction. Numerical simulations and experimental studies are performed to investigate the feasibility of the proposed method in estimating relaxation parameters and conductivity. Results: The proposed method, if compared with conventional magnetic resonance electrical impedance tomography, enables rapid data acquisition and simultaneous estimation of T1, T2, and current-induced Bz, yielding a comparable level of signal-to-noise ratio in the parameter estimates while retaining a relative conductivity contrast. Conclusion: We successfully demonstrated the feasibility of the proposed method in jointly estimating tissue relaxation parameters as well as conductivity distributions. It can be a promising, rapid imaging strategy for quantitative conductivity estimation.",
keywords = "Alternating steady-state-free-precession, Conductivity, Dual-echo-steady-state, Magnetic resonance imaging, Relaxation",
author = "Hyunyeol Lee and Sohn, {Chul Ho} and Jaeseok Park",
year = "2016",
doi = "10.1002/mrm.26350",
language = "English",
journal = "Magnetic Resonance in Medicine",
issn = "0740-3194",
publisher = "John Wiley and Sons Inc.",

}

TY - JOUR

T1 - Current-induced alternating reversed dual-echo-steady-state for joint estimation of tissue relaxation and electrical properties

AU - Lee, Hyunyeol

AU - Sohn, Chul Ho

AU - Park, Jaeseok

PY - 2016

Y1 - 2016

N2 - Purpose: To develop a current-induced, alternating reversed dual-echo-steady-state-based magnetic resonance electrical impedance tomography for joint estimation of tissue relaxation and electrical properties. Methods: The proposed method reverses the readout gradient configuration of conventional, in which steady-state-free-precession (SSFP)-ECHO is produced earlier than SSFP-free-induction-decay (FID) while alternating current pulses are applied in between the two SSFPs to secure high sensitivity of SSFP-FID to injection current. Additionally, alternating reversed dual-echo-steady-state signals are modulated by employing variable flip angles over two orthogonal injections of current pulses. Ratiometric signal models are analytically constructed, from which T1, T2, and current-induced Bz are jointly estimated by solving a nonlinear inverse problem for conductivity reconstruction. Numerical simulations and experimental studies are performed to investigate the feasibility of the proposed method in estimating relaxation parameters and conductivity. Results: The proposed method, if compared with conventional magnetic resonance electrical impedance tomography, enables rapid data acquisition and simultaneous estimation of T1, T2, and current-induced Bz, yielding a comparable level of signal-to-noise ratio in the parameter estimates while retaining a relative conductivity contrast. Conclusion: We successfully demonstrated the feasibility of the proposed method in jointly estimating tissue relaxation parameters as well as conductivity distributions. It can be a promising, rapid imaging strategy for quantitative conductivity estimation.

AB - Purpose: To develop a current-induced, alternating reversed dual-echo-steady-state-based magnetic resonance electrical impedance tomography for joint estimation of tissue relaxation and electrical properties. Methods: The proposed method reverses the readout gradient configuration of conventional, in which steady-state-free-precession (SSFP)-ECHO is produced earlier than SSFP-free-induction-decay (FID) while alternating current pulses are applied in between the two SSFPs to secure high sensitivity of SSFP-FID to injection current. Additionally, alternating reversed dual-echo-steady-state signals are modulated by employing variable flip angles over two orthogonal injections of current pulses. Ratiometric signal models are analytically constructed, from which T1, T2, and current-induced Bz are jointly estimated by solving a nonlinear inverse problem for conductivity reconstruction. Numerical simulations and experimental studies are performed to investigate the feasibility of the proposed method in estimating relaxation parameters and conductivity. Results: The proposed method, if compared with conventional magnetic resonance electrical impedance tomography, enables rapid data acquisition and simultaneous estimation of T1, T2, and current-induced Bz, yielding a comparable level of signal-to-noise ratio in the parameter estimates while retaining a relative conductivity contrast. Conclusion: We successfully demonstrated the feasibility of the proposed method in jointly estimating tissue relaxation parameters as well as conductivity distributions. It can be a promising, rapid imaging strategy for quantitative conductivity estimation.

KW - Alternating steady-state-free-precession

KW - Conductivity

KW - Dual-echo-steady-state

KW - Magnetic resonance imaging

KW - Relaxation

UR - http://www.scopus.com/inward/record.url?scp=84982946441&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84982946441&partnerID=8YFLogxK

U2 - 10.1002/mrm.26350

DO - 10.1002/mrm.26350

M3 - Article

C2 - 27489196

AN - SCOPUS:84982946441

JO - Magnetic Resonance in Medicine

JF - Magnetic Resonance in Medicine

SN - 0740-3194

ER -