Measurement of transverse relaxation times of J‐coupled metabolites in the human visual cortex at 4 T
Open Access
- 11 July 2011
- journal article
- research article
- Published by Wiley in Magnetic Resonance in Medicine
- Vol. 67 (4), 891-897
- https://doi.org/10.1002/mrm.23080
Abstract
Accurate quantification of 1H NMR spectra often requires knowledge of the relaxation times to correct for signal losses due to relaxation and saturation. In human brain, T2 values for singlets such as N‐acetylaspartate, creatine, and choline have been reported, but few T2 values are available for J‐coupled spin systems. The purpose of this study was to measure the T2 relaxation times of J‐coupled metabolites in the human occipital lobe using the LASER sequence. Spectra were acquired at multiple echo times and were analyzed with an LCModel using basis sets simulated at each echo time. Separate basis spectra were used for resonances of protons belonging to the same molecule but having very different T2 values (e.g., two separate basis spectra were used for the singlet and multiplet signal in N‐acetylaspartate). The T2 values for the N‐acetylaspartate multiplet (149 ± 12 ms), glutamate (125 ± 10 ms), myo‐inositol (139 ± 20 ms), and taurine (196 ± 28 ms) were successfully measured in the human visual cortex at 4 T. These measured T2 relaxation times have enabled the accurate and absolute quantification of cerebral metabolites at longer echo times. Magn Reson Med, 2011.Keywords
Funding Information
- NIH (BTRC P41 RR008079, NCC P30 NS057091)
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