title: Reproducibility of macromolecule suppressed GABA measurement using motion and shim navigated MEGA-SPECIAL with LCModel, jMRUI and GANNET.
abstract: OBJECTIVE
  Measuring the pure form of GABA has become increasingly important because of its association with behaviour and certain pathologies. The aim of this study was to assess the reproducibility of GABA measurements using a shim and motion navigated MEGA-SPECIAL sequence with LCModel, jMRUI and GANNET software.
  
  
  METHODS
  Motion and shim navigated MEGA-SPECIAL scans were acquired in 20 healthy subjects. Two acquisitions were performed for each of two regions: the anterior cingulate (ACC) and medial-parietal (PAR) cortices. Absolute GABA concentration ([Formula: see text]) and GABA-to-Creatine ratio (GABA/Cr) were quantified using the three software packages.
  
  
  RESULTS
  Using the within-subject coefficient of variation (CVws) as an index, reproducibility for both GABAH20and GABA/Cr ranged from 13 to 22 % in the ACC and 13 to 18 % in PAR using the three software packages.
  
  
  CONCLUSIONS
  Based on CVws, GABA concentrations in both the ACC and PAR are reproducible using a shim and motion navigated MEGA-SPECIAL sequence with any of the three software packages, thus demonstrating the ability to quantify the pure form of GABA using these software in studies relating GABA to pathology and healthy behaviour.
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, Western Cape, South Africa. mgsaleh7@gmail.com.|Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University, Baltimore, MD, USA. mgsaleh7@gmail.com.
authors.forename: Muhammad G
authors.initials: MG
authors.lastname: Saleh
authors.affiliation: Douglas Mental Health University Institute and Department of Psychiatry, McGill University, Montreal, Canada.
authors.forename: Jamie
authors.initials: J
authors.lastname: Near
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, Western Cape, South Africa.
authors.forename: Alqadafi
authors.initials: A
authors.lastname: Alhamud
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, Western Cape, South Africa.
authors.forename: Frances
authors.initials: F
authors.lastname: Robertson
authors.affiliation: Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
authors.forename: André J W
authors.initials: AJ
authors.lastname: van der Kouwe
authors.affiliation: MRC/UCT Medical Imaging Research Unit, Department of Human Biology, University of Cape Town, Cape Town, Western Cape, South Africa.
authors.forename: Ernesta M
authors.initials: EM
authors.lastname: Meintjes
mesh_terms: D000328:Adult; D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging; D001931:Brain Mapping; D005260:Female; D006179:Gyrus Cinguli / Q000000981:diagnostic imaging*; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009038:Motion; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted; D012984:Software; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000737:chemistry*
chemical_list: D046911:Macromolecular Substances; D005680:gamma-Aminobutyric Acid
keywords: 1H-MRS; Edited GABA analysis; GABA; Magnetic field correction; Motion correction