In vivo phosphorus polarization transfer and decoupling from protons in three-dimensional localized nuclear magnetic resonance spectroscopy of human brain.
Refocused insensitive nucleus enhancement by polarization transfer (RINEPT) from protons (1H) to a J-coupled phosphorus (31P) has been incorporated into three-dimensional (3D) chemical-shift-imaging (CSI) sequence on a clinical imager. The technique is demonstrated on a phantom and in in vivo human brain. The polarization-transfer efficiency (approximately 1.2) is lower than the theoretical maximum of gamma1H/gamma31P approximately 2.4 resulting from 1H-1H homonuclear J couplings of similar magnitude competing with the 1H --> 31P transfer. Nevertheless, compared with direct 31P Ernst-angle excitation, signal gains of up to x1.8 were obtained mainly as a result of T1 differences between 31P and the 1H. Spectral interpretation is simplified by editing out all non-proton-coupled 31P signals. The duration, approximately 50 min, and power deposition, approximately 1 W x kg(-1), make the application suitable for human studies.
Gonen
O
O
Department of Nuclear Magnetic Resonance and Medical Spectroscopy, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
Mohebbi
A
A
Stoyanova
R
R
Brown
T R
TR
D001921:Brain / Q000378:metabolism*; D004735:Energy Transfer; D004983:Ethanolamines / Q000032:analysis; D005260:Female; D006801:Humans; D006859:Hydrogen; D007089:Image Enhancement / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D019047:Phantoms, Imaging; D010725:Phosphocreatine / Q000032:analysis; D010758:Phosphorus; D010767:Phosphorylcholine / Q000032:analysis; D011522:Protons
D004983:Ethanolamines; D011522:Protons; D010725:Phosphocreatine; D010767:Phosphorylcholine; D010758:Phosphorus; C005448:phosphorylethanolamine; D006859:Hydrogen