Simultaneous determination of metabolite concentrations, T1and T2relaxation times.
OBJECTIVE
To simultaneously measure concentration and T1and T2values of metabolites in the human brain in a single scan session.


METHODS
A new pulse sequence with multiple variable acquisition parameters was proposed to encode metabolite T1and T2information into the acquired data. A linear combination-fitting algorithm was developed in-house to simultaneously determine metabolite concentrations and relaxation times.


RESULTS
Concentration, T1, and T2values of N-acetyl-aspartate, total creatine, total choline, and glutamate were reliably measured in the frontal gray matter and white matter regions of nine healthy volunteers at 7 tesla in less than 10 minutes of scan time per voxel. T1and T2values of glutamine, as well as T1of glutathione, were also measured in the frontal gray matter region with reasonable precision.


CONCLUSIONS
The proposed technique allows multiparametric characterization of brain metabolites in a single scan session, making it possible to measure both levels and intracellular microenvironments of brain chemicals in clinical MR spectroscopy studies. Magn Reson Med 78:2072-2081, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA.
Li
L
An
National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA.
Shizhe
S
Li
National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland, USA.
Jun
J
Shen
D000328:Adult; D000465:Algorithms; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001921:Brain / Q000000981:diagnostic imaging*; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging; D018698:Glutamic Acid / Q000032:analysis; D066128:Gray Matter / Q000000981:diagnostic imaging; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009010:Monte Carlo Method; D019047:Phantoms, Imaging; D066127:White Matter / Q000000981:diagnostic imaging; D055815:Young Adult
D001224:Aspartic Acid; D018698:Glutamic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline
Metabolite; T1; T2; high field; relaxation