title: In vivo 1H magnetic resonance imaging and spectroscopy of the rat spinal cord using an inductively-coupled chronically implanted RF coil.
abstract: An inductively coupled, chronically implanted short-solenoid coil was used to obtain in vivo localized 1H NMR spectra and diffusion-weighted images from a rat spinal cord. A 5 x 8 mm two-turn elliptically shaped solenoid coil was implanted in rats at the site of a T-12 vertebral-level laminectomy. Excitation was achieved solely by a 3 x 3 cm external surface coil, and signal detection was achieved by inductively coupling the external coil to the implanted coil. The image signal-to-noise ratio (SNR) obtained with the inductively-coupled implanted coil was compared with that obtained using a linear or a quadrature external surface coil. The implanted coil provided a gain by over a factor of 3 in SNR. The implanted coil was used to measure localized 1H spectra in vivo at the T13/L1 spinal-cord level within a 1.85 x 1.85 x 4.82 mm (16.5 microL) volume. With 256 averages, a approximately 3-s repetition delay and respiratory gating, a high-quality spectrum was acquired in 13 min. In addition, water translational diffusion was measured in three orthogonal directions using a stimulated-echo imaging sequence, with a short echo time (TE), to produce a quantitative map of diffusion in a rat spinal cord in vivo.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610-0245, USA.
authors.forename: X
authors.initials: X
authors.lastname: Silver
authors.forename: W X
authors.initials: WX
authors.lastname: Ni
authors.forename: E V
authors.initials: EV
authors.lastname: Mercer
authors.forename: B L
authors.initials: BL
authors.lastname: Beck
authors.forename: E L
authors.initials: EL
authors.lastname: Bossart
authors.forename: B
authors.initials: B
authors.lastname: Inglis
authors.forename: T H
authors.initials: TH
authors.lastname: Mareci
mesh_terms: D000818:Animals; D005260:Female; D008279:Magnetic Resonance Imaging / Q000295:instrumentation; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation; D019047:Phantoms, Imaging; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000033:anatomy & histology* / Q000378:metabolism*