Impact of frequency drift on gamma-aminobutyric acid-edited MR spectroscopy.
Title | Impact of frequency drift on gamma-aminobutyric acid-edited MR spectroscopy. |
Publication Type | Journal Article |
Year of Publication | 2014 |
Authors | Harris AD, Glaubitz B, Near J, C Evans J, Puts NAJ, Schmidt-Wilcke T, Tegenthoff M, Barker PB, Edden RAE |
Journal | Magn Reson Med |
Volume | 72 |
Issue | 4 |
Pagination | 941-8 |
Date Published | 2014 Oct |
ISSN | 1522-2594 |
Keywords | Adult, 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. |
DOI | 10.1002/mrm.25009 |
Alternate Journal | Magn Reson Med |
PubMed ID | 24407931 |
PubMed Central ID | PMC4017007 |
Grant List | P41 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 |