Skip to main content
Journal cover image

T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T.

Publication ,  Journal Article
Murali-Manohar, S; Borbath, T; Wright, AM; Soher, B; Mekle, R; Henning, A
Published in: Magn Reson Med
August 2020

PURPOSE: Relaxation times can contribute to spectral assignment. In this study, effective T2 relaxation times ( T2eff ) of macromolecules are reported for gray and white matter-rich voxels in the human brain at 9.4 T. The T2eff of macromolecules are helpful to understand their behavior and the effect they have on metabolite quantification. Additionally, for absolute quantification of metabolites with magnetic resonance spectroscopy, appropriate T2 values of metabolites must be considered. The T2 relaxation times of metabolites are calculated after accounting for TE/sequence-specific macromolecular baselines. METHODS: Macromolecular and metabolite spectra for a series of TEs were acquired at 9.4 T using double inversion-recovery metabolite-cycled semi-LASER and metabolite-cycled semi-LASER, respectively. The T2 relaxation times were calculated by fitting the LCModel relative amplitudes of macromolecular peaks and metabolites to a mono-exponential decay across the TE series. Furthermore, absolute concentrations of metabolites were calculated using the estimated relaxation times and internal water as reference. RESULTS: The T2eff of macromolecules are reported, which range from 13 ms to 40 ms, whereas, for metabolites, they range from 40 ms to 110 ms. Both macromolecular and metabolite T2 relaxation times are observed to follow the decreasing trend, with increasing B0 . The linewidths of metabolite singlets can be fully attributed to T2 and B0 components. However, in addition to these components, macromolecule linewidths have contributions from J-coupling and overlapping resonances. CONCLUSION: The T2 relaxation times of all macromolecular and metabolite peaks at 9.4 T in vivo are reported for the first time. Metabolite relaxation times were used to calculate the absolute metabolite concentrations.

Duke Scholars

Published In

Magn Reson Med

DOI

EISSN

1522-2594

Publication Date

August 2020

Volume

84

Issue

2

Start / End Page

542 / 558

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • Magnetic Resonance Spectroscopy
  • Magnetic Resonance Imaging
  • Macromolecular Substances
  • Humans
  • Brain Chemistry
  • Brain
  • 4003 Biomedical engineering
  • 0903 Biomedical Engineering
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Murali-Manohar, S., Borbath, T., Wright, A. M., Soher, B., Mekle, R., & Henning, A. (2020). T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T. Magn Reson Med, 84(2), 542–558. https://doi.org/10.1002/mrm.28174
Murali-Manohar, Saipavitra, Tamas Borbath, Andrew Martin Wright, Brian Soher, Ralf Mekle, and Anke Henning. “T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T.Magn Reson Med 84, no. 2 (August 2020): 542–58. https://doi.org/10.1002/mrm.28174.
Murali-Manohar S, Borbath T, Wright AM, Soher B, Mekle R, Henning A. T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T. Magn Reson Med. 2020 Aug;84(2):542–58.
Murali-Manohar, Saipavitra, et al. “T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T.Magn Reson Med, vol. 84, no. 2, Aug. 2020, pp. 542–58. Pubmed, doi:10.1002/mrm.28174.
Murali-Manohar S, Borbath T, Wright AM, Soher B, Mekle R, Henning A. T2 relaxation times of macromolecules and metabolites in the human brain at 9.4 T. Magn Reson Med. 2020 Aug;84(2):542–558.
Journal cover image

Published In

Magn Reson Med

DOI

EISSN

1522-2594

Publication Date

August 2020

Volume

84

Issue

2

Start / End Page

542 / 558

Location

United States

Related Subject Headings

  • Nuclear Medicine & Medical Imaging
  • Magnetic Resonance Spectroscopy
  • Magnetic Resonance Imaging
  • Macromolecular Substances
  • Humans
  • Brain Chemistry
  • Brain
  • 4003 Biomedical engineering
  • 0903 Biomedical Engineering