Spectral editing with adiabatic pulses.
Amplitude- and frequency-modulated pulses, known as adiabatic pulses, can induce uniform flip angles in the presence of extreme B1 inhomogeneity, which makes them advantageous for in vivo surface-coil studies. This paper describes the conversion of conventional (square pulse-based) spectral-editing sequences into their adiabatic counterparts. Eight adiabatic homo- and heteronuclear sequences are experimentally evaluated for lactate editing. For homonuclear lactate editing, gradient-enhanced multiple-quantum-coherence filtering provides the best overall performance (100% signal recovery with excellent water and lipid suppression in a single acquisition). For heteronuclear [3-(13)C]lactate editing, gradient-enhanced heteronuclear multiple-quantum-coherence filtering provides the best suppression of unwanted signals in a single acquisition, whereas J-modulated spin-echo sequences yield maximum sensitivity.
de Graaf
R A
RA
Center for Magnetic Resonance Research, University of Minnesota Medical School, Minneapolis 55455, USA.
Luo
Y
Y
Terpstra
M
M
Garwood
M
M
D000818:Animals; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000032:analysis; D001932:Brain Neoplasms / Q000378:metabolism; D002247:Carbon Isotopes; D002794:Choline / Q000032:analysis; D003401:Creatine / Q000032:analysis; D005240:Feasibility Studies; D005910:Glioma / Q000378:metabolism; D007773:Lactates / Q000032:analysis / Q000378:metabolism; D008055:Lipids; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008961:Models, Structural; D051381:Rats; D012815:Signal Processing, Computer-Assisted; D014867:Water
D002247:Carbon Isotopes; D007773:Lactates; D008055:Lipids; D014867:Water; D001224:Aspartic Acid; C000179:N-acetylaspartate; D003401:Creatine; D002794:Choline