TY - JOUR
T1 - Proton echo-planar spectroscopic imaging of J-coupled resonances in human brain at 3 and 4 Tesla
AU - Posse, Stefan
AU - Otazo, Ricardo
AU - Caprihan, Arvind
AU - Bustillo, Juan
AU - Chen, Hongji
AU - Henry, Pierre Gilles
AU - Marjanska, Malgorzata
AU - Gasparovic, Charles
AU - Zuo, Chun
AU - Magnotta, Vincent
AU - Mueller, Bryon
AU - Mullins, Paul
AU - Renshaw, Perry
AU - Ugurbil, Kamil
AU - Lim, Kelvin O.
AU - Alger, Jeffry R.
PY - 2007/8
Y1 - 2007/8
N2 - In this multicenter study, 2D spatial mapping of J-coupled resonances at 3T and 4T was performed using short-TE (15 ms) proton echo-planar spectroscopic imaging (PEPSI). Water-suppressed (WS) data were acquired in 8.5 min with 1-cm3 spatial resolution from a supraventricular axial slice. Optimized outer volume suppression (OVS) enabled mapping in close proximity to peripheral scalp regions. Constrained spectral fitting in reference to a non-WS (NWS) scan was performed with LCModel using correction for relaxation attenuation and partial-volume effects. The concentrations of total choline (tCho), creatine + phosphocreatine (Cr+PCr), glutamate (Glu), glutamate + glutamine (Glu+Gln), myo-inositol (Ins), NAA, NAA+NAAG, and two macromolecular resonances at 0.9 and 2.0 ppm were mapped with mean Cramer-Rao lower bounds (CRLBs) between 6% and 18% and ∼150-cm3 sensitive volumes. Aspartate, GABA, glutamine (Gln), glutathione (GSH), phosphoethanolamine (PE), and macromolecules (MMs) at 1.2 ppm were also mapped, although with larger mean CRLBs between 30% and 44%. The CRLBs at 4T were 19% lower on average as compared to 3T, consistent with a higher signal-to-noise ratio (SNR) and increased spectral resolution. Metabolite concentrations were in the ranges reported in previous studies. Glu concentration was significantly higher in gray matter (GM) compared to white matter (WM), as anticipated. The short acquisition time makes this methodology suitable for clinical studies.
AB - In this multicenter study, 2D spatial mapping of J-coupled resonances at 3T and 4T was performed using short-TE (15 ms) proton echo-planar spectroscopic imaging (PEPSI). Water-suppressed (WS) data were acquired in 8.5 min with 1-cm3 spatial resolution from a supraventricular axial slice. Optimized outer volume suppression (OVS) enabled mapping in close proximity to peripheral scalp regions. Constrained spectral fitting in reference to a non-WS (NWS) scan was performed with LCModel using correction for relaxation attenuation and partial-volume effects. The concentrations of total choline (tCho), creatine + phosphocreatine (Cr+PCr), glutamate (Glu), glutamate + glutamine (Glu+Gln), myo-inositol (Ins), NAA, NAA+NAAG, and two macromolecular resonances at 0.9 and 2.0 ppm were mapped with mean Cramer-Rao lower bounds (CRLBs) between 6% and 18% and ∼150-cm3 sensitive volumes. Aspartate, GABA, glutamine (Gln), glutathione (GSH), phosphoethanolamine (PE), and macromolecules (MMs) at 1.2 ppm were also mapped, although with larger mean CRLBs between 30% and 44%. The CRLBs at 4T were 19% lower on average as compared to 3T, consistent with a higher signal-to-noise ratio (SNR) and increased spectral resolution. Metabolite concentrations were in the ranges reported in previous studies. Glu concentration was significantly higher in gray matter (GM) compared to white matter (WM), as anticipated. The short acquisition time makes this methodology suitable for clinical studies.
KW - Glutamate
KW - Human brain
KW - Magnetic resonance spectroscopic imaging
KW - Proton echo planar spectroscopic imaging
KW - Spectral quantification
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U2 - 10.1002/mrm.21287
DO - 10.1002/mrm.21287
M3 - Article
C2 - 17610279
AN - SCOPUS:34547935607
SN - 0740-3194
VL - 58
SP - 236
EP - 244
JO - Magnetic resonance in medicine
JF - Magnetic resonance in medicine
IS - 2
ER -