CONtrast Conformed Electrical Properties Tomography (CONCEPT) Based on Multi-Channel Transmission and Alternating Direction Method of Multipliers

Research output: Contribution to journalArticle

Abstract

In magnetic resonance-based electrical properties tomography (EPT), circularly polarized magnetic field B 1 from a transmit radiofrequency (RF) coil is measured and utilized to infer the electrical conductivity and permittivity of biological tissues. Compared with a quadrature RF coil, a multi-channel transmit coil provides a plurality of unique transmit B 1 patterns that help to alleviate the under-determinedness of EPT reconstruction problem, and it also allows to circumvent the 'transceive phase assumption' that fails at ultra-high-field MRI. Here, a new approach, contrast conformed electrical properties tomography or CONCEPT, is proposed based on the multi-channel transmission that retrieves electrical properties (EPs) by solving a linear partial differential equation with discriminated L 1 and L 2 norm regularization informed by intermediate EP gradient. The theory of CONCEPT and a fast reconstruction algorithm based on the alternating direction method of multipliers are described and evaluated using numerical simulations, phantom experiment, and analysis of in vivo human brain data at 7 T MRI. Compared with the multi-channel gradient-based EPT (gEPT) method, this new technology does not require receive-B 1 sensitivity profiles and does not rely on symmetry assumption regarding RF coil design and imaged target. Moreover, it is not dependent on external prior information, such as integration seed point or anatomical MRI, which can be sources of bias in reconstructed EP values. By deriving EPs from transmit B 1 profiles only, CONCEPT can be used with RF coils that include receive-only arrays with large channel count which can, in turn, offer substantial gains in signal-to-noise ratio. It also holds potentials to image unsymmetrical body organs and diseased brain. CONCEPT provides solutions for the practical problems during the implementation of gEPT, thus representing a more generalized framework in the context of multi-channel RF transmission.

Original languageEnglish (US)
Article number8434234
Pages (from-to)349-359
Number of pages11
JournalIEEE Transactions on Medical Imaging
Volume38
Issue number2
DOIs
StatePublished - Feb 1 2019

Fingerprint

Tomography
Electric properties
Magnetic resonance imaging
Electric Conductivity
Direction compound
Body Image
Brain
Brain Diseases
Signal-To-Noise Ratio
Magnetic Fields
Seeds
Magnetic Resonance Spectroscopy
Magnetic resonance
Technology
Partial differential equations
Seed
Signal to noise ratio
Permittivity
Tissue
Magnetic fields

Keywords

  • B mapping
  • Electrical properties tomography (EPT)
  • alternating direction method of multipliers (ADMM)
  • magnetic resonance imaging (MRI)
  • multichannel transmission

PubMed: MeSH publication types

  • Journal Article
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

Cite this

@article{d7a1e89da856423b8305723373e4d22f,
title = "CONtrast Conformed Electrical Properties Tomography (CONCEPT) Based on Multi-Channel Transmission and Alternating Direction Method of Multipliers",
abstract = "In magnetic resonance-based electrical properties tomography (EPT), circularly polarized magnetic field B 1 from a transmit radiofrequency (RF) coil is measured and utilized to infer the electrical conductivity and permittivity of biological tissues. Compared with a quadrature RF coil, a multi-channel transmit coil provides a plurality of unique transmit B 1 patterns that help to alleviate the under-determinedness of EPT reconstruction problem, and it also allows to circumvent the 'transceive phase assumption' that fails at ultra-high-field MRI. Here, a new approach, contrast conformed electrical properties tomography or CONCEPT, is proposed based on the multi-channel transmission that retrieves electrical properties (EPs) by solving a linear partial differential equation with discriminated L 1 and L 2 norm regularization informed by intermediate EP gradient. The theory of CONCEPT and a fast reconstruction algorithm based on the alternating direction method of multipliers are described and evaluated using numerical simulations, phantom experiment, and analysis of in vivo human brain data at 7 T MRI. Compared with the multi-channel gradient-based EPT (gEPT) method, this new technology does not require receive-B 1 sensitivity profiles and does not rely on symmetry assumption regarding RF coil design and imaged target. Moreover, it is not dependent on external prior information, such as integration seed point or anatomical MRI, which can be sources of bias in reconstructed EP values. By deriving EPs from transmit B 1 profiles only, CONCEPT can be used with RF coils that include receive-only arrays with large channel count which can, in turn, offer substantial gains in signal-to-noise ratio. It also holds potentials to image unsymmetrical body organs and diseased brain. CONCEPT provides solutions for the practical problems during the implementation of gEPT, thus representing a more generalized framework in the context of multi-channel RF transmission.",
keywords = "B mapping, Electrical properties tomography (EPT), alternating direction method of multipliers (ADMM), magnetic resonance imaging (MRI), multichannel transmission",
author = "Yicun Wang and {Van de Moortele}, Pierre-Francois and Bin He",
year = "2019",
month = "2",
day = "1",
doi = "10.1109/TMI.2018.2865121",
language = "English (US)",
volume = "38",
pages = "349--359",
journal = "IEEE Transactions on Medical Imaging",
issn = "0278-0062",
publisher = "Institute of Electrical and Electronics Engineers Inc.",
number = "2",

}

TY - JOUR

T1 - CONtrast Conformed Electrical Properties Tomography (CONCEPT) Based on Multi-Channel Transmission and Alternating Direction Method of Multipliers

AU - Wang, Yicun

AU - Van de Moortele, Pierre-Francois

AU - He, Bin

PY - 2019/2/1

Y1 - 2019/2/1

N2 - In magnetic resonance-based electrical properties tomography (EPT), circularly polarized magnetic field B 1 from a transmit radiofrequency (RF) coil is measured and utilized to infer the electrical conductivity and permittivity of biological tissues. Compared with a quadrature RF coil, a multi-channel transmit coil provides a plurality of unique transmit B 1 patterns that help to alleviate the under-determinedness of EPT reconstruction problem, and it also allows to circumvent the 'transceive phase assumption' that fails at ultra-high-field MRI. Here, a new approach, contrast conformed electrical properties tomography or CONCEPT, is proposed based on the multi-channel transmission that retrieves electrical properties (EPs) by solving a linear partial differential equation with discriminated L 1 and L 2 norm regularization informed by intermediate EP gradient. The theory of CONCEPT and a fast reconstruction algorithm based on the alternating direction method of multipliers are described and evaluated using numerical simulations, phantom experiment, and analysis of in vivo human brain data at 7 T MRI. Compared with the multi-channel gradient-based EPT (gEPT) method, this new technology does not require receive-B 1 sensitivity profiles and does not rely on symmetry assumption regarding RF coil design and imaged target. Moreover, it is not dependent on external prior information, such as integration seed point or anatomical MRI, which can be sources of bias in reconstructed EP values. By deriving EPs from transmit B 1 profiles only, CONCEPT can be used with RF coils that include receive-only arrays with large channel count which can, in turn, offer substantial gains in signal-to-noise ratio. It also holds potentials to image unsymmetrical body organs and diseased brain. CONCEPT provides solutions for the practical problems during the implementation of gEPT, thus representing a more generalized framework in the context of multi-channel RF transmission.

AB - In magnetic resonance-based electrical properties tomography (EPT), circularly polarized magnetic field B 1 from a transmit radiofrequency (RF) coil is measured and utilized to infer the electrical conductivity and permittivity of biological tissues. Compared with a quadrature RF coil, a multi-channel transmit coil provides a plurality of unique transmit B 1 patterns that help to alleviate the under-determinedness of EPT reconstruction problem, and it also allows to circumvent the 'transceive phase assumption' that fails at ultra-high-field MRI. Here, a new approach, contrast conformed electrical properties tomography or CONCEPT, is proposed based on the multi-channel transmission that retrieves electrical properties (EPs) by solving a linear partial differential equation with discriminated L 1 and L 2 norm regularization informed by intermediate EP gradient. The theory of CONCEPT and a fast reconstruction algorithm based on the alternating direction method of multipliers are described and evaluated using numerical simulations, phantom experiment, and analysis of in vivo human brain data at 7 T MRI. Compared with the multi-channel gradient-based EPT (gEPT) method, this new technology does not require receive-B 1 sensitivity profiles and does not rely on symmetry assumption regarding RF coil design and imaged target. Moreover, it is not dependent on external prior information, such as integration seed point or anatomical MRI, which can be sources of bias in reconstructed EP values. By deriving EPs from transmit B 1 profiles only, CONCEPT can be used with RF coils that include receive-only arrays with large channel count which can, in turn, offer substantial gains in signal-to-noise ratio. It also holds potentials to image unsymmetrical body organs and diseased brain. CONCEPT provides solutions for the practical problems during the implementation of gEPT, thus representing a more generalized framework in the context of multi-channel RF transmission.

KW - B mapping

KW - Electrical properties tomography (EPT)

KW - alternating direction method of multipliers (ADMM)

KW - magnetic resonance imaging (MRI)

KW - multichannel transmission

UR - http://www.scopus.com/inward/record.url?scp=85051644931&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85051644931&partnerID=8YFLogxK

U2 - 10.1109/TMI.2018.2865121

DO - 10.1109/TMI.2018.2865121

M3 - Article

VL - 38

SP - 349

EP - 359

JO - IEEE Transactions on Medical Imaging

JF - IEEE Transactions on Medical Imaging

SN - 0278-0062

IS - 2

M1 - 8434234

ER -