Indirect imaging of ethanol via magnetization transfer at high and low magnetic fields.
Ethanol (EtOH) is believed to exert its neurochemical effects through interactions with brain cellular components, which causes a fraction of brain EtOH to have a lower molecular mobility. This facilitates magnetization transfer to other molecules similarly associated with macromolecules, such as water. It was hypothesized that this effect can be used in vivo to image EtOH indirectly via the much stronger brain tissue water resonance. EtOH-containing bovine serum albumin samples were used to demonstrate magnetic coupling between EtOH and water at 7 T and 1.5 T. Spectroscopy and imaging experiments demonstrated that EtOH signal saturation yielded greater water signal reduction than inversion and that this reduction scaled with EtOH concentration in the BSA samples. In human brain at physiologically relevant brain EtOH concentrations, water signal reductions were measurable when saturating the EtOH resonance. Strengths and limitations of indirectly imaging brain EtOH are discussed.
Estilaei
Mohammad R
MR
MR Unit DVA Medical Center, Department of Radiology, University of California-San Francisco, 4150 Clement Street 114M, San Francisco, CA 94121, USA.
Matson
Gerald B
GB
Meyerhoff
Dieter J
DJ
D001921:Brain / Q000378:metabolism*; D000431:Ethanol / Q000493:pharmacokinetics*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D014867:Water / Q000378:metabolism
D014867:Water; D000431:Ethanol