Localized 2D J-resolved 1H MR spectroscopy: strong coupling effects in vitro and in vivo.
A two-dimensional (2D) J-resolved MR spectroscopy sequence (2D J-PRESS), fully localized in three dimensions, has been implemented on a whole-body MR scanner. A modified PRESS sequence with [90 degrees-180 degrees-t1/2-180 degrees-t1/2-acquisition] was used for voxel localization. An incremental delay (t1/2) was added to the intervals before and after the last slice-selective 180 degree RF pulse to monitor the J-evolution in a localized 2D MR spectrum. Spectra were recorded with phantoms containing common cerebral metabolites--alanine, N-acetyl aspartate, glutamine, glutamate, taurine, myo-inositol, glucose, aspartate, GABA, and choline at 50 mM. In conformity with previously reported results, additional cross-peaks due to strong coupling were monitored in many metabolites. A brain phantom was developed to mimic the gray matter of human brain with the metabolites at physiological concentrations (0.5-12 mM). In vivo 2D J-PRESS spectra (n = 18) of healthy human brain were in conformity with those recorded from the brain phantom.
Ryner
L N
LN
Department of Medical Physics, University of Wisconsin, Madison 53706, USA.
Sorenson
J A
JA
Thomas
M A
MA
D000409:Alanine / Q000378:metabolism; D001921:Brain / Q000378:metabolism*; D002794:Choline / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D005973:Glutamine / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D007294:Inositol / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019047:Phantoms, Imaging; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005971:Glutamates; D005973:Glutamine; D007294:Inositol; D005680:gamma-Aminobutyric Acid; D002794:Choline; D000409:Alanine