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 Experiment Videos

Concomitant gradient terms in phase contrast MR: analysis and correction

M A Bernstein1, X J Zhou, J A Polzin

  • 1GE Medical Systems, Waukesha, Wisconsin 53188, USA.

Magnetic Resonance in Medicine
|February 20, 1998
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Patient experience and acceptance of a lightweight, compact 3 Tesla MRI system.

Radiography (London, England : 1995)·2026
Same author

Anatomical and fMRI-network comparison of multiple DLPFC targeting strategies for repetitive transcranial magnetic stimulation treatment of depression.

Brain stimulation·2021
Same author

Average SAR prediction, validation, and evaluation for a compact MR scanner head-sized RF coil.

Magnetic resonance imaging·2021
Same author

Targeting location relates to treatment response in active but not sham rTMS stimulation.

Brain stimulation·2021
Same author

A novel surgery: robotic transanal rectal mucosal harvest.

Techniques in coloproctology·2019
Same author

Gradient nonlinearity calibration and correction for a compact, asymmetric magnetic resonance imaging gradient system.

Physics in medicine and biology·2016
Same journal

Feasibility and SNR Performance of Hyperpolarized <sup>129</sup>Xe Gas Exchange Imaging Using a Balanced SSFP Sequence.

Magnetic resonance in medicine·2026
Same journal

Multi-Contrast Human Brain CEST MRI at 11.7 T: First In Vivo Demonstration.

Magnetic resonance in medicine·2026
Same journal

Suppression of Oscillation and Ghosting in RF-Spoiled Gradient-Echo-Based Dynamic Imaging.

Magnetic resonance in medicine·2026
Same journal

A Simple, Dynamic Geometric Phantom for MRI and CT Reconstruction Pipelines: Beyond Shepp-Logan.

Magnetic resonance in medicine·2026
Same journal

7T 3D-EPI PCASL With High SNR Efficiency and Robustness to Through-Plane B<sub>0</sub> Field Gradients.

Magnetic resonance in medicine·2026
Same journal

A Comparison of Tissue Property Values Estimated Using Conventional Cardiac MRF and MT-Cardiac MRF.

Magnetic resonance in medicine·2026
See all related articles

Researchers discovered new cross-terms in concomitant magnetic fields during MRI scans. These terms, arising from simultaneous gradient use, impact phase contrast imaging and require new error reduction methods.

Area of Science:

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

Background:

  • Concomitant magnetic fields arise from linear gradients in MRI due to Maxwell's equations.
  • These fields have non-linear spatial dependence and are crucial for image formation.
  • Existing literature describes these fields, but lowest-order cross-terms were previously unidentified.

Purpose of the Study:

  • To theoretically and experimentally identify and characterize new lowest-order terms in concomitant magnetic fields, termed cross-terms.
  • To investigate the impact of concomitant gradient terms on phase contrast imaging.
  • To develop and demonstrate methods for mitigating phase errors caused by these fields.

Main Methods:

  • Theoretical derivation of concomitant field terms based on Maxwell's equations.

Related Experiment Videos

  • Experimental validation of the existence of cross-terms.
  • Analysis of phase contrast imaging under the influence of concomitant fields.
  • Development and testing of error reduction techniques, including a joint pulse sequence-reconstruction method.

    • Main Results:

    • Identified two additional lowest-order terms in the concomitant field, the cross-terms.
    • Demonstrated that cross-terms occur when longitudinal (Gz) and transverse (Gx or Gy) gradients are simultaneously active.
    • Showed that these concomitant gradient terms significantly affect phase contrast imaging.
    • Validated a novel joint pulse sequence-reconstruction method that effectively reduces phase errors without increasing minimum echo time (TE).

    Conclusions:

    • The newly identified concomitant gradient cross-terms are a significant factor in MRI, particularly in phase contrast imaging.
    • Effective methods exist for reducing or eliminating phase errors caused by concomitant fields.
    • The developed joint pulse sequence-reconstruction method offers a practical solution for mitigating these errors.
    • The importance of understanding and managing concomitant fields will grow with advancements in stronger gradients and weaker main magnetic fields in MRI systems.