Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

NMR Spectrometers: Resolution and Error Correction01:14

NMR Spectrometers: Resolution and Error Correction

993
When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction decay. Fourier transform of an exponential decay yields a Lorentzian peak in the frequency domain. Lorentzian peaks in an NMR spectrum are defined by their amplitude, full width at half maximum, and position, where the peak width is governed by the spin-spin relaxation time alone. In real experiments, however, the applied magnetic field is rendered...
993
Plane Electromagnetic Waves II01:29

Plane Electromagnetic Waves II

3.1K
Consider a plane wavefront traveling in position x-direction with a constant speed. This wavefront can be utilized to obtain the relationship between electric and magnetic fields with the help of Faraday's law.
3.1K
NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences01:17

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

1.8K
A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a radio frequency pulse along the x-axis, the nuclei absorb energy corresponding to their Larmor frequencies and achieve resonance. This shifts the net magnetization vector from the z-axis toward the transverse plane. This angle of rotation of the magnetization vector, or the flip angle, is proportional to the duration and intensity of the pulse.
1.8K
Atomic Nuclei: Larmor Precession Frequency01:11

Atomic Nuclei: Larmor Precession Frequency

3.5K
The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) that causes the mass to 'wobble' around the gravitational field axis in a phenomenon called precession. Similarly, the magnetic moment (μ) of a spinning nucleus precesses due to an external magnetic field directed along the z-axis. The precession of the magnetic moment vector about the magnetic field is called Larmor precession,...
3.5K
Reconstruction of Signal using Interpolation01:10

Reconstruction of Signal using Interpolation

920
Signal processing techniques are essential for accurately converting continuous signals to digital formats and vice versa. When a continuous signal is sampled with a period T, the resulting sampled signal exhibits replicas of the original spectrum in the frequency domain, spaced at intervals equal to the sampling frequency. To handle this sampled signal, a zero-order hold method can be applied, which creates a piecewise constant signal by retaining each sample's value until the next...
920
Magnetic Field Of A Current Loop01:16

Magnetic Field Of A Current Loop

6.1K
Consider a circular loop with a radius a, that carries a current I. The magnetic field due to the current at an arbitrary point P along the axis of the loop can be calculated using the Biot-Savart law.
6.1K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Spin-echo measurements for capillary rheometry at low field.

Magnetic resonance letters·2026
Same author

Characterization of shale using T<sub>2</sub>-T<sub>2</sub><sup>∗</sup> relaxation correlation measurements.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same author

Velocity measurement in porous media using steady-state free precession-Analytical solution to the Bloch-Torrey equation with flow.

The Journal of chemical physics·2025
Same author

T<sub>2</sub>-T<sub>2</sub><sup>∗</sup> relaxation correlation measurement.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2025
Same author

State of Charge in a Vanadium Redox Flow Battery Measured via <sup>1</sup>H MR Relaxation with Low Field Portable Magnets.

Analytical chemistry·2025
Same author

Multinuclear MR and MRI study of lithium-ion cells using a variable field magnet and a fixed frequency RF probe.

Magnetic resonance letters·2025
Same journal

Localization-driven exchange contrast in diffusion exchange spectroscopy.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

4.5 Tesla superconducting miniature magnet in liquid nitrogen.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Folding and unfolding dynamics of a DNA aptamer studied by heteronuclear <sup>1</sup>H-<sup>13</sup>C correlation zz-exchange spectroscopy.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Multi-spin control from one-spin pulses.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Altering MRI rotating frame relaxations by changing the truncation level of Hyperbolic Secant pulse.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
Same journal

Effects of proton exchange on the lifetimes of long-lived states in aliphatic chains.

Journal of magnetic resonance (San Diego, Calif. : 1997)·2026
See all related articles

Related Experiment Video

Updated: May 5, 2026

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques
09:01

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques

Published on: April 4, 2017

7.8K

Arbitrary magnetic field gradient waveform correction using an impulse response based pre-equalization technique.

Frédéric G Goora1, Bruce G Colpitts2, Bruce J Balcom3

  • 1Department of Electrical and Computer Engineering, University of New Brunswick, 15 Dineen Drive, Fredericton, NB E3B 5A3, Canada; MRI Centre, Department of Physics, University of New Brunswick, 8 Bailey Drive, Fredericton, NB E3B 5A3, Canada.

Journal of Magnetic Resonance (San Diego, Calif. : 1997)
|December 10, 2013
PubMed
Summary
This summary is machine-generated.

This study introduces a method to measure magnetic field gradient impulse response, enabling the creation of pre-equalized waveforms. This improves magnetic resonance imaging (MRI) by reducing eddy current-induced image quality degradation.

Keywords:
Eddy currentsImpulse responseMagnetic field gradient waveform correctionOptimal gradient waveformsPre-equalization

More Related Videos

High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition
05:11

High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition

Published on: June 27, 2025

873
Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation
09:36

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Published on: May 12, 2014

13.2K

Related Experiment Videos

Last Updated: May 5, 2026

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques
09:01

Gain-compensation Methodology for a Sinusoidal Scan of a Galvanometer Mirror in Proportional-Integral-Differential Control Using Pre-emphasis Techniques

Published on: April 4, 2017

7.8K
High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition
05:11

High-precision Electromagnetic Flowmeter with Empty Pipe Detection via Complex Programmable Logic Device-based Waveform Recognition

Published on: June 27, 2025

873
Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation
09:36

Extracting Visual Evoked Potentials from EEG Data Recorded During fMRI-guided Transcranial Magnetic Stimulation

Published on: May 12, 2014

13.2K

Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Electromagnetism
  • Signal Processing

Background:

  • Time-varying magnetic fields in MRI induce eddy currents on conductive structures.
  • These eddy currents degrade MRI image quality, necessitating mitigation strategies.
  • Existing methods aim to characterize and minimize eddy current impacts.

Purpose of the Study:

  • To present a method for directly measuring magnetic field gradient temporal evolution.
  • To extract the system impulse response for gradient waveform analysis.
  • To develop a pre-equalization technique for optimizing gradient waveforms in MRI.

Main Methods:

  • Utilizing the magnetic field gradient waveform monitor method with step-like input functions.
  • Applying system theory analysis assuming linearity and time invariance of the gradient system.
  • Developing an algorithm to calculate physically realizable pre-equalized waveforms accounting for system limitations.

Main Results:

  • Successful measurement of gradient system impulse response.
  • Determination of pre-equalized waveforms for improved gradient response fidelity.
  • Demonstrated significant improvements in magnetic field gradient waveform fidelity post-pre-equalization.

Conclusions:

  • The developed method effectively measures gradient system impulse response.
  • Pre-equalization significantly enhances magnetic field gradient waveform fidelity.
  • This approach offers a viable solution to mitigate eddy current-induced image degradations in MRI.