Molar quantitation of in vivo proton metabolites in human brain with 3D magnetic resonance spectroscopic imaging.
A method for molar quantitation of in vivo proton metabolites in human brain with three-dimensional (3D) proton magnetic resonance spectroscopic imaging (MRSI) is described. The method relies on comparison of brain and calibration phantom measurements, with corrections for coil loading, and spin-lattice and spin-spin relaxation times. A 3D proton MRSI pulse sequence was developed which acquires two echoes and enables acquisition of both the TMS coil loading reference phantom and proton metabolite signals from a single experiment. With the aqueous fraction (tissue water) taken into account, the calculated molar concentrations from 24 centrum semiovale white matter voxels from 4 control subjects were (mmol/l +/- SD): N-acetyl aspartate = 14.6 +/- 2.8, total creatine+phosphocreatine = 6.0 +/- 1.2, total choline = 1.9 +/- 0.4. These values are equivalent to previously reported results obtained from single volume localized proton magnetic resonance spectroscopy.
Husted
C A
CA
Magnetic Resonance Unit, Department of Veterans Affairs Medical Center, San Francisco, CA 94121.
Duijn
J H
JH
Matson
G B
GB
Maudsley
A A
AA
Weiner
M W
MW
D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001923:Brain Chemistry; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007773:Lactates / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D010725:Phosphocreatine / Q000032:analysis
D007773:Lactates; D010725:Phosphocreatine; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline