Impact of frequency drift on gamma-aminobutyric acid-edited MR spectroscopy.

TitleImpact of frequency drift on gamma-aminobutyric acid-edited MR spectroscopy.
Publication TypeJournal Article
Year of Publication2014
AuthorsHarris AD, Glaubitz B, Near J, C Evans J, Puts NAJ, Schmidt-Wilcke T, Tegenthoff M, Barker PB, Edden RAE
JournalMagn Reson Med
Volume72
Issue4
Pagination941-8
Date Published2014 Oct
ISSN1522-2594
KeywordsAdult, Algorithms, Artifacts, Brain, Female, gamma-Aminobutyric Acid, Humans, Macromolecular Substances, Magnetic Resonance Spectroscopy, Male, Neurotransmitter Agents, Reproducibility of Results, Sensitivity and Specificity
Abstract

PURPOSE: To investigate the quantitative impact of frequency drift on Gamma-Aminobutyric acid (GABA+)-edited MRS of the human brain at 3 Tesla (T).METHODS: Three sequential GABA+-edited MEGA-PRESS acquisitions were acquired in fifteen sessions; in ten of these, MRS was preceded by functional MRI (fMRI) to induce frequency drift, which was estimated from the creatine resonance at 3.0 ppm. Simulations were performed to examine the effects of frequency drift on the editing efficiency of GABA and co-edited macromolecules (MM) and of subtraction artifacts on GABA+ quantification. The efficacy of postprocessing frequency correction was also investigated.RESULTS: Gradient-induced frequency drifts affect GABA+ quantification for at least 30 min after imaging. Average frequency drift was low in control sessions and as high as -2 Hz/min after fMRI. Uncorrected frequency drift has an approximately linear effect on GABA+ measurements with a -10 Hz drift resulting in a 16% decrease in GABA+, primarily due to subtraction artifacts.CONCLUSION: Imaging acquisitions with high gradient duty cycles can impact subsequent GABA+ measurements. Postprocessing can address subtraction artifacts, but not changes in editing efficiency or GABA:MM signal ratios; therefore, protocol design should avoid intensive gradient sequences before edited MRS Magn Reson Med 72:941-948, 2014. © 2013 Wiley Periodicals, Inc.

DOI10.1002/mrm.25009
Alternate JournalMagn Reson Med
PubMed ID24407931
PubMed Central IDPMC4017007
Grant ListP41 EB015909 / EB / NIBIB NIH HHS / United States
P41 EB015909 / EB / NIBIB NIH HHS / United States
R01 EB016089 / EB / NIBIB NIH HHS / United States
R01 EB016089 / EB / NIBIB NIH HHS / United States
R01 MH096263 / MH / NIMH NIH HHS / United States
R01 MH096263 / MH / NIMH NIH HHS / United States
R21 NS077300 / NS / NINDS NIH HHS / United States
R21 NS077300 / NS / NINDS NIH HHS / United States