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: Radiofrequency Pulses and Pulse Sequences01:17

NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

790
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.
790
Aliasing01:18

Aliasing

128
Accurate signal sampling and reconstruction are crucial in various signal-processing applications. A time-domain signal's spectrum can be revealed using its Fourier transform. When this signal is sampled at a specific frequency, it results in multiple scaled replicas of the original spectrum in the frequency domain. The spacing of these replicas is determined by the sampling frequency.
If the sampling frequency is below the Nyquist rate, these replicas overlap, preventing the original...
128
Upsampling01:22

Upsampling

225
Managing signal sampling rates is essential in digital signal processing to maintain signal integrity. A decimated signal, characterized by a reduced frequency range due to its lower sampling rate, can be upsampled by inserting zeros between each sample. This upsampling process expands the original spectrum and introduces repeated spectral replicas at intervals dictated by the new Nyquist frequency. To refine this zero-inserted sequence, it is passed through a lowpass filter with a cutoff...
225
Downsampling01:20

Downsampling

149
When considering a sampled sequence with zero values between sampling instants, one can replace it by taking every N-th value of the sequence. At these integer multiples of N, the original and sampled sequences coincide. This process, known as decimation, involves extracting every N-th sample from a sequence, thereby creating a more efficient sequence.
The Fourier transform of the decimated sequence reveals a combination of scaled and shifted versions of the original spectrum. This...
149
Double Resonance Techniques: Overview01:12

Double Resonance Techniques: Overview

197
Double resonance techniques in Nuclear Magnetic Resonance (NMR) spectroscopy involve the simultaneous application of two different frequencies or radiofrequency pulses to manipulate and observe two distinct nuclear spins. One important application of double resonance is spin decoupling, which selectively suppresses coupling with one type of nucleus while observing the NMR signal from another nucleus, simplifying the spectrum and enhancing resolution.
Spin decoupling is usually achieved by...
197
Reconstruction of Signal using Interpolation01:10

Reconstruction of Signal using Interpolation

191
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...
191

You might also read

Related Articles

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

Sort by
Same author

Comparative Assessment of Graglia-Wilton-Peterson and Rao-Wilton-Glisson Basis Functions for Radiofrequency Coil Modeling in Magnetic Resonance Imaging.

IEEE journal on multiscale and multiphysics computational techniques·2026
Same author

Exercise-Induced Alterations in Lung Water Density in Heart Failure Using Single-Breath-Hold 3D Ultrashort Echo Time MRI.

Journal of magnetic resonance imaging : JMRI·2026
Same author

Respiratory Motion Management in Abdominal MRI: Revisiting the Gap Between Technical Advances and Clinical Translation.

Magnetic resonance in medicine·2026
Same author

Hybrid learning: a combination of self-supervised and supervised learning for joint MRI reconstruction and denoising in low-field MRI.

Physics in medicine and biology·2026
Same author

Software-defined Radar for MRI Motion Correction: A versatile, vendor-independent Platform.

medRxiv : the preprint server for health sciences·2026
Same author

Single-Shot 2D Radial Echo Planar Imaging for Functional MRI.

Magnetic resonance in medicine·2026

Related Experiment Video

Updated: Jun 23, 2025

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
09:30

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Published on: December 18, 2016

19.5K

Fat suppression using frequency-sweep RF saturation and iterative reconstruction.

Ruoxun Zi1, Thomas Benkert1, Hersh Chandarana1

  • 1The Bernard and Irene Schwartz Center for Biomedical Imaging, Department of Radiology, New York University Grossman School of Medicine, New York, New York, USA.

Magnetic Resonance in Medicine
|June 18, 2024
PubMed
Summary
This summary is machine-generated.

This study presents a novel fat suppression technique effective in low-field MRI and adaptable to high-field imaging with B0 inhomogeneities. The method ensures reliable fat suppression and offers potential for quantitative fat/water analysis.

Keywords:
fat suppressioniterative reconstructionlow field

More Related Videos

Fat-Water Phantoms for Magnetic Resonance Imaging Validation: A Flexible and Scalable Protocol
07:59

Fat-Water Phantoms for Magnetic Resonance Imaging Validation: A Flexible and Scalable Protocol

Published on: September 7, 2018

11.3K
Author Spotlight: Using Hyperpolarized Xenon-129 MRI to Study Lung Diseases
09:55

Author Spotlight: Using Hyperpolarized Xenon-129 MRI to Study Lung Diseases

Published on: January 5, 2024

1.2K

Related Experiment Videos

Last Updated: Jun 23, 2025

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease
09:30

Quantitative Magnetic Resonance Imaging of Skeletal Muscle Disease

Published on: December 18, 2016

19.5K
Fat-Water Phantoms for Magnetic Resonance Imaging Validation: A Flexible and Scalable Protocol
07:59

Fat-Water Phantoms for Magnetic Resonance Imaging Validation: A Flexible and Scalable Protocol

Published on: September 7, 2018

11.3K
Author Spotlight: Using Hyperpolarized Xenon-129 MRI to Study Lung Diseases
09:55

Author Spotlight: Using Hyperpolarized Xenon-129 MRI to Study Lung Diseases

Published on: January 5, 2024

1.2K

Area of Science:

  • Magnetic Resonance Imaging (MRI)
  • Medical Physics
  • Radiology

Background:

  • Conventional fat suppression methods in MRI are often ineffective at low magnetic fields due to narrow spectral separation.
  • Strong B0 inhomogeneities in high-field MRI can also compromise the performance of standard fat suppression techniques.

Purpose of the Study:

  • To introduce an alternative fat suppression technique suitable for both low-field MRI and high-field applications with B0 inhomogeneities.
  • To address the limitations of current fat suppression methods in challenging imaging scenarios.

Main Methods:

  • Fat and water separation is achieved by sweeping radiofrequency (RF) saturation pulse frequencies during continuous radial acquisition.
  • Frequency-resolved images are reconstructed using regularized iterative methods, enabling voxel-wise signal-response curve extraction for fat/water classification.
  • Water-only composite images are generated, and the principle is demonstrated using 3D balanced SSFP and gradient-recalled echo sequences at 0.55T and 3T.

Main Results:

  • Experiments with a proton density fat fraction (PDFF) phantom validated the reliability of fat/water separation.
  • The approach demonstrated uniform fat suppression without water signal loss and improved CSF-to-fat signal ratio in 0.55T abdominal imaging.
  • Consistent fat suppression was achieved in 3T neck exams, even where conventional methods failed due to B0 inhomogeneities. Simultaneous fat/water quantification feasibility was shown.

Conclusions:

  • The proposed principle offers reliable fat suppression for low-field MRI and adapts to high-field MRI with B0 inhomogeneity.
  • This technique provides a foundation for developing alternative methods for quantitative fat/water (PDFF) measurement.