Research
Print page Print page
Switch language
The Capital Region of Denmark - a part of Copenhagen University Hospital
Published

Prospective frequency correction for macromolecule-suppressed GABA editing at 3T

Research output: Contribution to journalJournal articleResearchpeer-review

DOI

  1. Tractography reproducibility challenge with empirical data (TraCED): The 2017 ISMRM diffusion study group challenge

    Research output: Contribution to journalJournal articleResearchpeer-review

  2. Comparison of four MRI protocols for detection of extrahepatic colorectal cancer metastases

    Research output: Contribution to journalJournal articleResearchpeer-review

  3. Brain capillary transit time heterogeneity in healthy volunteers measured by dynamic contrast-enhanced T1 -weighted perfusion MRI

    Research output: Contribution to journalJournal articleResearchpeer-review

  4. Comparison of global cerebral blood flow measured by phase-contrast mapping MRI with (15) O-H2 O positron emission tomography

    Research output: Contribution to journalJournal articleResearchpeer-review

  1. Prospective motion correction in single voxel spectroscopy at 7T using fat navigators and higher order shimming

    Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

  2. Pre-Acquisition Adjustments (B0 Shimming, B1 Shimming & Water Suppression)

    Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

  3. Ultra-high field MR angiography in human migraine models: a 3.0 T/7.0 T comparison study

    Research output: Contribution to journalJournal articleResearchpeer-review

  • Richard A E Edden
  • Georg Oeltzschner
  • Ashley D Harris
  • Nicolaas A J Puts
  • Kimberly L Chan
  • Vincent Boer
  • Michael Schär
  • Peter B Barker
View graph of relations

PURPOSE: To investigate the effects of B0 field offsets and drift on macromolecule (MM)-suppressed GABA-editing experiments, and to implement and test a prospective correction scheme. "Symmetric" editing schemes are proposed to suppress unwanted coedited MM signals in GABA editing.

MATERIALS AND METHODS: Full density-matrix simulations of both conventional (nonsymmetric) and symmetric MM-suppressed editing schemes were performed for the GABA spin system to evaluate their offset-dependence. Phantom and in vivo (15 subjects at 3T) GABA-edited experiments with symmetrical suppression of MM signals were performed to quantify the effects of field offsets on the total GABA+MM signal (designated GABA+). A prospective frequency correction method based on interleaved water referencing (IWR) acquisitions was implemented and its experimental performance evaluated during positive and negative drift.

RESULTS: Simulations show that the signal from MM-suppressed symmetrical editing schemes is an order of magnitude more susceptible to field offsets than the signal from nonsymmetric editing schemes. The MM-suppressed GABA signal changes by 8.6% per Hz for small field offsets. IWR significantly reduces variance in the field offset and measured GABA levels (both P < 0.001 by F-tests), maintaining symmetric suppression of MM signal.

CONCLUSION: Symmetrical editing schemes substantially increase the dependence of measurements on B0 field offsets, which can arise due to patient movement and/or scanner instability. It is recommended that symmetrical editing should be used in combination with effective B0 stabilization, such as that provided by IWR. J. Magn. Reson. Imaging 2016.

Original languageEnglish
JournalJournal of magnetic resonance imaging : JMRI
Volume44
Issue number6
Pages (from-to)1474-1482
Number of pages9
ISSN1053-1807
DOIs
Publication statusPublished - Nov 2016

ID: 46474195