Xenon-129 MR imaging and spectroscopy of rat brain using arterial delivery of hyperpolarized xenon in a lipid emulsion.
Hyperpolarized (129)Xe dissolved in a lipid emulsion constitutes an NMR tracer that can be injected into the blood stream, enabling blood-flow measurement and perfusion imaging. A small volume (0.15 ml) of this tracer was injected in 1.5 s in rat carotid and (129)Xe MR spectra and images were acquired at 2.35 T to evaluate the potential of this approach for cerebral studies. Xenon spectra consistently showed two resonances, at 194.5 ppm and 199.0 ppm relative to the gas peak. The signal-to-noise ratio (SNR) obtained for the two peaks was sufficient (ranging from 12 to 90) to follow their time courses. 2D transverse-projection xenon images were obtained with an in-plane resolution of 900 microm per pixel (SNR range 8-15). Histological analysis revealed no brain damage except in two rats that had received three injections.
Duhamel
G
G
Laboratoire mixte INSERM U438 / Université Joseph Fourier "RMN Bioclinique," Laboratoire de Recherche Correspondant du CEA, Grenoble, France.
Choquet
P
P
Grillon
E
E
Lamalle
L
L
Leviel
J L
JL
Ziegler
A
A
Constantinesco
A
A
D000818:Animals; D001921:Brain / Q000098:blood supply*; D004655:Emulsions; D007275:Injections, Intravenous; D008055:Lipids / Q000008:administration & dosage / Q000493:pharmacokinetics; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D051381:Rats; D012815:Signal Processing, Computer-Assisted; D014979:Xenon Isotopes / Q000008:administration & dosage / Q000493:pharmacokinetics*
D004655:Emulsions; D008055:Lipids; D014979:Xenon Isotopes