14,413 Hits in 6.1 sec

Finding neuroelectric activity under magnetic-field oscillations (NAMO) with magnetic resonance imaging in vivo

T.-K. Truong, A. W. Song
2006 Proceedings of the National Academy of Sciences of the United States of America  
Electrical stimulation of the median nerve was achieved by applying a series of 1 ms-long current pulses, triggered at the onset of the negative lobes of the oscillating gradients.  ...  We therefore extended this technique by incorporating a series of oscillating magnetic field gradients applied in synchrony with the stimulation to drastically increase its sensitivity, and we recently  ...  Tozer for their assistance with the MRI scanning; R. Segal and C. Lin for performing the electromyography measurements; A. Perkins and T.  ... 
doi:10.1073/pnas.0605486103 pmid:16894177 pmcid:PMC1567924 fatcat:lwcdmnbjyrerpnbgtedgo64aci

Lorentz effect imaging of ionic currents in solution

Trong-Kha Truong, Alexandru Avram, Allen W. Song
2008 Journal of magnetic resonance (San Diego, Calif. 1997 : Print)  
oscillating gradients.  ...  References Fig. 1 : 1 (A) Axial images of the phantom acquired with different current amplitudes and polarities. (B) Difference images with the reference image acquired without current.  ... 
doi:10.1016/j.jmr.2007.12.005 pmid:18180187 fatcat:tfjsb7l5jrc5fnerixbr2s3eum

Synchronized detection of minute electrical currents with MRI using Lorentz effect imaging

Trong-Kha Truong, Jennifer L. Wilbur, Allen W. Song
2006 Journal of magnetic resonance (San Diego, Calif. 1997 : Print)  
its feasibility for imaging randomly oriented electrical currents on the order of microamperes with a temporal resolution on the order of milliseconds in gel phantoms.  ...  The blood oxygenation level-dependent (BOLD) effect is the most commonly used contrast mechanism in functional magnetic resonance imaging (fMRI), due to its relatively high spatial resolution and sensitivity  ...  Axial images were acquired with oscillating gradients applied in the direction orthogonal to both the wire and the main magnetic field, since the Lorentz force-induced displacement occurs in that direction  ... 
doi:10.1016/j.jmr.2005.11.012 pmid:16343959 pmcid:PMC1540538 fatcat:jdnkrec3yzen5ei5ixcoz77fdi

The role of magnetic forces in biology and medicine

Bradley J Roth
2011 Experimental biology and medicine  
of conductivity, 4) magneto-acoustic tomography with magnetic induction, and 5) Lorentz force imaging of action currents using magnetic resonance imaging.  ...  The Lorentz force (the force acting on currents in a magnetic field) plays an increasingly larger role in techniques to image current and conductivity.  ...  I focus on magnetic forces that act on electric current, with an emphasis on how these forces can be used to image current or conductivity.  ... 
doi:10.1258/ebm.2010.010236 pmid:21321309 pmcid:PMC3079438 fatcat:tal4xkrixzaijmfoiwaaxsglsi

Reduction of flow- and eddy-currents-induced image artifacts in coronary magnetic resonance angiography using a linear centric-encoding SSFP sequence

Xiaoming Bi, Jaeseok Park, Vibhas Deshpande, Orlando Simonetti, Gerhard Laub, Debiao Li
2007 Magnetic Resonance Imaging  
Flow and gradient switching induced eddy currents are important sources of such phase errors, especially under off-resonant condition.  ...  In conclusion, flow and eddy currents induced imaging artifacts in coronary MRA using SSFP sequence can be markedly reduced with LCE acquisition of PE lines.  ...  Eddy current is induced by the electric fields resulting from changing magnetic flux (6) .  ... 
doi:10.1016/j.mri.2007.01.004 pmid:17905246 pmcid:PMC2084053 fatcat:74rxukb7qfhajau4jqtwb4wk2a

High resolution in-operando microimaging of solar cells with pulsed electrically-detected magnetic resonance

Itai Katz, Matthias Fehr, Alexander Schnegg, Klaus Lips, Aharon Blank
2015 Journal of magnetic resonance (San Diego, Calif. 1997 : Print)  
electric current of the device while inducing electron spin-flip transitions.  ...  the electrical current of the sample.  ...  (a) Drawing of the cryogenic pEDMRI probe with electrical and optical supply lines, the gradient coil array, and the resonator insertion module with mounted solar cell.  ... 
doi:10.1016/j.jmr.2014.11.008 pmid:25557860 fatcat:35tnsttvkvaxxes3ktf7bqpsve

Electromagnetohydrodynamic modeling of Lorentz Effect Imaging

Navid Pourtaheri, Trong-Kha Truong, Craig S. Henriquez
2013 Journal of magnetic resonance (San Diego, Calif. 1997 : Print)  
Three computational models of an electrolyte-filled phantom subject to an applied current dipole, synchronized to oscillating magnetic field gradients of an LEI protocol, were developed to determine the  ...  The simulated images were compared to images from previous LEI phantom experiments with identical properties for different stimulus current amplitudes and polarities.  ...  The motion-induced phase accumulation of each particle spin, p, is therefore enhanced by the application of oscillating gradients over the total oscillating gradient period.  ... 
doi:10.1016/j.jmr.2013.08.011 pmid:24056273 pmcid:PMC3818387 fatcat:fqucfzxm35evjn5jsyqc2mg7a4

Ultrasensitive mechanical detection of magnetic moment using a commercial disk drive write head

Y. Tao, A. Eichler, T. Holzherr, C. L. Degen
2016 Nature Communications  
In addition, we demonstrate quantitative imaging of the pole field with about 10 nm spatial resolution.  ...  Sensitive detection of weak magnetic moments is an essential capability in many areas of nanoscale science and technology, including nanomagnetism, quantum readout of spins, and nanoscale magnetic resonance  ...  The oscillating field in turn induces an oscillating sample magnetization M ¼ wB/m 0 .  ... 
doi:10.1038/ncomms12714 pmid:27647039 pmcid:PMC5034305 fatcat:57cnisqqvbgovnut33frw7tjye

Selective addressing of solid-state spins at the nanoscale via magnetic resonance frequency encoding

H. Zhang, K. Arai, C. Belthangady, J.-C. Jaskula, R. L. Walsworth
2017 npj Quantum Information  
Tailored application of gradient fields and resonant microwaves allow site-selective nitrogen vacancy spin manipulation and sensing applications, including Rabi oscillations, imaging, and nuclear magnetic  ...  Microcoils fabricated on the diamond chip provide electrically tuneable magnetic field gradients~0.1 G/nm.  ...  We gratefully acknowledge the provision of diamond samples by Element 6 and helpful technical and theoretical discussions with Liang Jiang and Nathalie de Leon.  ... 
doi:10.1038/s41534-017-0033-3 fatcat:g5rc4iaolbhofox2dpuiguyec4

Magnetic resonance imaging of time-varying magnetic fields from therapeutic devices

Luis Hernandez-Garcia, Vivek Bhatia, Krishan Prem-Kumar, Magnus Ulfarsson
2013 NMR in Biomedicine  
While magnetic resonance imaging of static magnetic fields generated by external probes has been previously demonstrated, there is an unmet need to image time-varying magnetic fields, such as those generated  ...  The method is able to reconstruct the three-dimensional components of the oscillating magnetic field vector.  ...  of the electrical properties (permittivity, conductivity, …, etc.) of the tissue is known.  ... 
doi:10.1002/nbm.2919 pmid:23355446 pmcid:PMC3645268 fatcat:dkbezf2pjvadhh6qmet2y2nbly

Magnetic-Resonance-Based Electrical Properties Tomography: A Review

Xiaotong Zhang, Jiaen Liu, Bin He
2014 IEEE Reviews in Biomedical Engineering  
in quantifying radiofrequency (RF) coil induced Specific Absorption Rate (SAR) which is a major safety concern in high-and ultrahigh-field Magnetic Resonance Imaging (MRI) applications.  ...  Recently introduced Electrical Properties Tomography (EPT) approaches utilize the measurable RF magnetic field induced by the RF coil in an MRI system to quantitatively reconstruct the EP distribution  ...  from Magnetic Resonance Current Density Imaging (MRCDI) [30] , [31] , measures the local magnetic field induced by surface current injection, and reconstructs static cross-sectional conductivity images  ... 
doi:10.1109/rbme.2013.2297206 pmid:24803104 pmcid:PMC4113345 fatcat:g74halcdmzgfjge4m3qv7mezpe

Selective addressing of solid-state spins at the nanoscale via magnetic resonance frequency encoding [article]

Huiliang Zhang, Keigo Arai, Chinmay Belthangady, Jean-Christophe Jaskula, Ronald L. Walsworth
2016 arXiv   pre-print
Tailored application of gradient fields and resonant microwaves allow site-selective NV spin manipulation and sensing applications, including Rabi oscillations, imaging, and nuclear magnetic resonance  ...  Microcoils fabricated on the diamond chip provide electrically tuneable magnetic-field gradients ~0.1 G/nm.  ...  We gratefully acknowledge the provision of diamond samples by Element 6 and helpful technical and theoretical discussions with Liang Jiang and Nathalie de Leon. Author Contributions  ... 
arXiv:1610.06630v1 fatcat:4ppheyeqlvh27mek3ayni7wpku

Magnetic Resonance Imaging System Based on Earth's Magnetic Field

Aleš Mohorič, Gorazd Planinšič, Miha Kos, Andrej Duh, Janez Stepišnik
2004 Instrumentation Science & Technology  
This article describes both the setup and the use of a system for magnetic resonance imaging (MRI) in the Earth's magnetic field.  ...  A reference signal of a fixed-frequency oscillator cannot be used since the Larmor frequency changes with time, following temporal fluctuations of Earth's magnetic field.  ...  As the current in the coils decays after a few oscillations, the magnetization remains in the plane perpendicular to B 0 and free induction signal is induced.  ... 
doi:10.1081/ci-200037034 fatcat:k4nqkis7vrdcrkppkudgsy4emu

Artifacts in Magnetic Resonance Imaging [chapter]

Michael Hoff, Jalal Andre, Brent Stewart
2016 Image Principles, Neck, and the Brain  
With the expected proliferation of these neural probes and potential clinical adoption, the magnetic resonance imaging (MRI) compatibility of GC microstructures needs to be established to help validate  ...  We also showed that because of their low magnetic susceptibility and lower conductivity, the GC microelectrodes caused almost no susceptibility shift artifacts and no eddy-current-induced artifacts compared  ...  circuit mode. d Measurement of the induced current using a shunt resistor of 1 Ω Comparison of magnetic resonance imaging artifact of GC and Pt microelectrode from T1 -weighted and T2-weighted images captured  ... 
doi:10.1201/b19609-10 fatcat:qsyhl4zxbngtjp3vttbfz2ir4m

Spin readout of trapped electron qubits

Pai Peng, Clemens Matthiesen, Hartmut Häffner
2017 Physical Review A  
We propose a scheme to read out the spin of a single electron quantum bit in a surface Paul trap using oscillating magnetic field gradients.  ...  An analysis of the the four procedures shows short measurement times (25 μs) and high fidelities (99.7%) are achievable with realistic experimental parameters.  ...  Leibfried for pointing out the problem with the electric field produced by current-carrying wires.  ... 
doi:10.1103/physreva.95.012312 fatcat:b45pts5bgvhw5p4tigm2lwnvuq
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