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Quantitative analysis of short echo time 1 H‐MRSI of cerebral gray and white matter
Author(s) -
McLean Mary A.,
Woermann Friedrich G.,
Barker Gareth J.,
Duncan John S.
Publication year - 2000
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/1522-2594(200009)44:3<401::aid-mrm10>3.0.co;2-w
Subject(s) - white matter , metabolite , chemistry , magnetic resonance spectroscopic imaging , nuclear magnetic resonance , creatine , nuclear medicine , glutamine , magnetic resonance imaging , medicine , physics , radiology , biochemistry , amino acid
Quantitative analysis of 1 H‐magnetic resonance spectroscopic imaging (MRSI) data was developed using the user‐independent spectral analysis routine LCModel. Tissue segmentation was performed using statistical parametric mapping software (SPM 96), and the results were used to correct for cerebrospinal fluid contamination. A correction was developed for the imperfections in the spectroscopic excitation profile in order to improve the uniformity of metabolite images. After validation in phantoms, these techniques were applied to study differences in metabolite concentrations between gray and white matter in normal volunteers (n = 13). A positive correlation was found between concentration and gray matter content for most metabolites studied. The estimated ratios of metabolite concentration in gray vs. white matter were: N‐acetyl aspartate + N‐acetyl aspartyl glutamate (NAc) = 1.16 ± 0.11; creatine = 1.7 ± 0.3; glutamate + glutamine = 2.4 ± 0.5; myo‐inositol = 1.6 ± 0.3; choline = 0.9 ± 0.2. The ratio of NAc/Cr was negatively correlated with gray matter content: gray/white = 0.69 ± 0.08. These methods will be useful in the evaluation of metabolite concentrations in MRSI voxels with mixed tissue composition in patient groups. Magn Reson Med 44:401–411, 2000. © 2000 Wiley‐Liss, Inc.