Magnetic Resonance Current Density Imaging of Chemical Processes and Reactions

Beravs, Katarina; Demšar, Alojz; Demšar, Franci

doi:10.1006/jmre.1998.1648

Cited by 13 publications

(9 citation statements)

References 8 publications

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“…Current density and conductivity mapping by MRI enables spatial and temporal changes in the concentrations of ionic species to be monitored during chemical reactions [127] and tablet dissolution [128]. From  c , the magnetic field component B c is determined and the current density calculated using Ampere's law [128].…”

Section: Current Density and Conductivity Imagingmentioning

confidence: 99%

“…Spatially heterogeneous chemical reactions have also been mapped by CDI. The formation of calcium carbonate, by the perfusion of gaseous CO 2 in saturated calcium hydroxide solution [127], was visualized through observation of the current density, which was high in the calcium hydroxide solution, due to the presence of Ca 2+ and OHions, but, was low where CaCO 3 formed. Over time, the region containing CaCO 3 was observed to increase, until all the calcium hydroxide was transformed into calcium carbonate.…”

Section: Current Density and Conductivity Imagingmentioning

confidence: 99%

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MRI of chemical reactions and processes

Britton

2017

Progress in Nuclear Magnetic Resonance Spectroscopy

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As magnetic resonance imaging (MRI) can spatially resolve a wealth of molecular information available from nuclear magnetic resonance (NMR), it is able to non-invasively visualise the composition, properties and reactions of a broad range of spatially-heterogeneous molecular systems. Hence, MRI is increasingly finding applications in the study of chemical reactions and processes in a diverse range of environments and technologies. This article will explain the basic principles of MRI and how it can be used to visualise chemical composition and molecular properties, providing an overview of the variety of information available. Examples are drawn from the disciplines of chemistry, chemical engineering, environmental science, physics, electrochemistry and materials science. The review introduces a range of techniques used to produce image contrast, along with the chemical and molecular insight accessible through them. Methods for mapping the distribution of chemical species, using chemical shift imaging or spatially-resolved spectroscopy, are reviewed, as well as methods for visualising physical state, temperature, current density, flow velocities and molecular diffusion. Strategies for imaging materials with low signal intensity, such as those containing gases or low sensitivity nuclei, using compressed sensing, para-hydrogen or polarisation transfer, are discussed. Systems are presented which encapsulate the diversity of chemical and physical parameters observable by MRI, including one- and two-phase flow in porous media, chemical pattern formation, phase transformations and hydrodynamic (fingering) instabilities. Lastly, the emerging area of electrochemical MRI is discussed, with studies presented on the visualisation of electrochemical deposition and dissolution processes during corrosion and the operation of batteries, supercapacitors and fuel cells.

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Section: Current Density and Conductivity Imagingmentioning

confidence: 99%

Section: Current Density and Conductivity Imagingmentioning

confidence: 99%

MRI of chemical reactions and processes

Britton

2017

Progress in Nuclear Magnetic Resonance Spectroscopy

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“…In this work, higher current density has been observed in T50/80 mammary carcinomas and SA-1 sarcomas than in the normal tissue. Beravs et al (34,35) used MRCDI to monitor conductivity changes that take place during dissolving of sodium chloride and the formation of calcium carbonate. Beravs et al (33) used MRCDI to diagnose osteoporosis and to determine the current pathways around bone fractures.…”

Section: Current State In Literaturementioning

confidence: 99%

“…Gamba and Delpy (36) investigated the effect of the skull on current density in the brain. Beravs et al (34,35) used RF-CDI to quantitatively monitor the depolarizations evoked by excitatory amino acids in a rat brain and observed excitatory changes as high conductivity regions, mainly in the hippocampal area, on current density images. This study revealed that only about 14-16% of the sagittally or bilaterally applied current passed through the skull in rabbits.…”

Section: Rfmentioning

confidence: 99%

Magnetic Resonance Current Density Imaging

Eyüboğlu

2006

Wiley Encyclopedia of Biomedical Engineering

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Magnetic resonance current density imaging (MRCDI) is an emerging modality that is used to image current density distribution created by an externally applied current to a conductor that contains nuclear magnetic resonance (NMR) active nuclei. Distribution of externally applied electrical current inside the body provides important information in many biomedical engineering applications: such as improvement of electrical stimulation devices by optimal electrode designs for electrosurgery, defibrillation, and cardiac pacing; optimization of defibrillation efficacy; determination of electrode geometry and current level in cancer treatment; electroconvulsive therapy; and noninvasive localization of epileptic spikes in the brain and determination of fatal current levels. Knowledge of current density distribution originating from a pair of electrodes can be used to calculate lead‐sensitivity maps of biopotential recording electrodes, and to improve the sensivity matrix used in electrical impedance tomography (EIT) image reconstruction. Finally, accurate measurement of current density distribution leads to high‐resolution conductivity imaging.

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“…The methods have been used to image current distribution in vitro [8][9][10][11], to monitor chemical processes [12,13] and also to image current pathways and tissue conductivity in vivo [14][15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%