title: Comparison of single voxel brain MRS AT 3T and 7T using 32-channel head coils.
abstract: OBJECTIVE
  The purpose of this study was to compare magnetic resonance spectroscopy (MRS) of three different regions of the human brain between 3 and 7 Tesla, using the same subjects and closely matched methodology at both field strengths.
  
  
  METHODS
  A semi-LASER (sLASER) pulse sequence with TE 32ms was used to acquire metabolite spectrum along with the water reference at 3T and 7T using similar experimental parameters and hardware at both field strengths (n=4 per region and field). Spectra were analyzed in LCModel using a simulated basis set.
  
  
  RESULTS
  Signal-to-noise ratio (SNR) at 7T was higher compared to 3T, and linewidths (in ppm) at both field strengths were comparable in ppm scale. Of the 13 metabolites reported in the paper, most metabolites were measured with higher precision at 7T in all three regions.
  
  
  CONCLUSIONS
  The study confirms gains in SNR and measurement precision at 7T in all three representative brain regions using the sLASER pulse sequence coupled with a 32-channel phased-array head coil.
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA. Electronic address: subechhya@jhmi.edu.
authors.forename: Subechhya
authors.initials: S
authors.lastname: Pradhan
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Susanne
authors.initials: S
authors.lastname: Bonekamp
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Centre, Kennedy Krieger Institute, Baltimore, MD, USA.
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Gillen
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: Laura M
authors.initials: LM
authors.lastname: Rowland
authors.affiliation: Maryland Psychiatric Research Center, Department of Psychiatry, University of Maryland School of Medicine, Baltimore, MD, USA.
authors.forename: S Andrea
authors.initials: SA
authors.lastname: Wijtenburg
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Richard A E
authors.initials: RA
authors.lastname: Edden
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, MD, USA; F.M. Kirby Research Centre, Kennedy Krieger Institute, Baltimore, MD, USA.
authors.forename: Peter B
authors.initials: PB
authors.lastname: Barker
mesh_terms: D000328:Adult; D001921:Brain / Q000033:anatomy & histology* / Q000378:metabolism*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation*; D008297:Male; D011829:Radiation Dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution; D014159:Transducers
keywords: 3 Tesla; 7 Tesla; Brain; Magnetic resonance spectroscopy; Semi-LASER