Comparison of the repeatability of GABA-edited magnetic resonance spectroscopy with and without macromolecule suppression

TitleComparison of the repeatability of GABA-edited magnetic resonance spectroscopy with and without macromolecule suppression
Publication TypeJournal Article
Year of Publication2016
AuthorsMikkelsen M, Singh KD, Sumner P, C Evans J
JournalMagn Reson Med
Volume75
Issue3
Pagination946-53
Date Published2016 Mar
ISSN1522-2594
KeywordsAdult, Brain, Brain Chemistry, Female, gamma-Aminobutyric Acid, Humans, Image Processing, Computer-Assisted, Magnetic Resonance Imaging, Male, Phantoms, Imaging, Reproducibility of Results, Signal Processing, Computer-Assisted, Young Adult
Abstract

PURPOSE: The inhibitory neurotransmitter γ-aminobutyric acid (GABA) can be measured in vivo using edited magnetic resonance spectroscopy (MRS), but quantification suffers from contamination by macromolecules (MM). It is possible to suppress this contamination using symmetric editing, but this procedure potentially compromises reliability of the GABA measurement. The aim of this study was to compare the repeatability of GABA-edited MRS with and without MM suppression.

METHODS: GABA' (non-MM contaminated) and GABA'+MM (MM-contaminated) concentration was measured in the occipital lobe (OCC) and anterior cingulate (AC) using symmetric and standard editing (n = 15). Each method was performed twice in each region.

RESULTS: Within-participant coefficients of variation for each technique were 4.0% (GABA'+MM) and 8.6% (GABA') in the OCC and 14.8% (GABA'+MM) and 12.6% (GABA') in the AC. Intraclass correlation coefficients were better for the suppression method than standard editing in both the OCC (0.72 versus 0.67) and AC (0.41 versus 0.16). These findings were replicated in the OCC of a second cohort (n = 15).

CONCLUSION: Symmetric suppression is shown to be comparable in repeatability to standard GABA-editing. Measuring a purer quantification of GABA becomes increasingly important as more research is conducted on links between GABA concentration, pathology and healthy behavior.

DOI10.1002/mrm.25699
Alternate JournalMagn Reson Med
PubMed ID25920455