Proton-decoupled, Overhauser-enhanced, spatially localized carbon-13 spectroscopy in humans
Abstract
Spatially localized, natural abundance, carbon (13C) NMR spectroscopy has been combined with proton (1H) decoupling and nuclear Overhauser enhancement to improve 13C sensitivity up to five-fold in the human leg, liver, and heart. Broadhand-decoupled 13C spectra were acquired in 1 s to 17 min with a conventional 1.5-T imaging/spectroscopy system, an auxiliary 1H decoupler, an air-cooled dual-coil coplanar surface probe, and both depth-resolved surface coil spectroscopy (DRESS) and one-dimensional phase-encoding gradient NMR pulse sequences. The surface coil probe comprised circular and figure-eight-shaped coils to eliminate problems with mutual coupling of coils at high decoupling power levels applied during 13C reception. Peak decoupler RF power deposition in tissue was computed numerically from electromagnetic theory assuming a semi-infinite plane of uniform biological conductor. Peak values at the surface were calculated at 4 to 6 W/kg in any gram of tissue for each watt of decoupler power input excluding all coil and cable losses, warning of potential local RF heating problems in these and related experiments. The average power deposition was about 9 mW/kg per watt input, which should present no systemic hazard. At 3 W input, human 13C spectra were decoupled to a depth of about 5 cm while some Overhauser enhancementmore »
- Authors:
-
- GE Corporate Research and Development Center, Schenectady, NY (USA)
- Publication Date:
- OSTI Identifier:
- 7137761
- Resource Type:
- Journal Article
- Journal Name:
- Magnetic Resonance in Medicine; (USA)
- Additional Journal Information:
- Journal Volume: 12:3; Journal ID: ISSN 0740-3194
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 62 RADIOLOGY AND NUCLEAR MEDICINE; HEART; NMR IMAGING; LEGS; LIVER; CARBON 13; CITRIC ACID; GLYCOGEN; MAN; METABOLITES; NUCLEAR MAGNETIC RESONANCE; OVERHAUSER EFFECT; PROTONS; ANIMALS; BARYONS; BODY; BODY AREAS; CARBOHYDRATES; CARBON ISOTOPES; CARBOXYLIC ACIDS; CARDIOVASCULAR SYSTEM; DIAGNOSTIC TECHNIQUES; DIGESTIVE SYSTEM; ELEMENTARY PARTICLES; EVEN-ODD NUCLEI; FERMIONS; GLANDS; HADRONS; HYDROXY ACIDS; ISOTOPES; LIGHT NUCLEI; LIMBS; MAGNETIC RESONANCE; MAMMALS; NUCLEI; NUCLEONS; ORGANIC ACIDS; ORGANIC COMPOUNDS; ORGANS; POLYSACCHARIDES; PRIMATES; RESONANCE; SACCHARIDES; STABLE ISOTOPES; VERTEBRATES; 550600* - Medicine
Citation Formats
Bottomley, P A, Hardy, C J, Roemer, P B, and Mueller, O M. Proton-decoupled, Overhauser-enhanced, spatially localized carbon-13 spectroscopy in humans. United States: N. p., 1989.
Web. doi:10.1002/mrm.1910120307.
Bottomley, P A, Hardy, C J, Roemer, P B, & Mueller, O M. Proton-decoupled, Overhauser-enhanced, spatially localized carbon-13 spectroscopy in humans. United States. https://doi.org/10.1002/mrm.1910120307
Bottomley, P A, Hardy, C J, Roemer, P B, and Mueller, O M. 1989.
"Proton-decoupled, Overhauser-enhanced, spatially localized carbon-13 spectroscopy in humans". United States. https://doi.org/10.1002/mrm.1910120307.
@article{osti_7137761,
title = {Proton-decoupled, Overhauser-enhanced, spatially localized carbon-13 spectroscopy in humans},
author = {Bottomley, P A and Hardy, C J and Roemer, P B and Mueller, O M},
abstractNote = {Spatially localized, natural abundance, carbon (13C) NMR spectroscopy has been combined with proton (1H) decoupling and nuclear Overhauser enhancement to improve 13C sensitivity up to five-fold in the human leg, liver, and heart. Broadhand-decoupled 13C spectra were acquired in 1 s to 17 min with a conventional 1.5-T imaging/spectroscopy system, an auxiliary 1H decoupler, an air-cooled dual-coil coplanar surface probe, and both depth-resolved surface coil spectroscopy (DRESS) and one-dimensional phase-encoding gradient NMR pulse sequences. The surface coil probe comprised circular and figure-eight-shaped coils to eliminate problems with mutual coupling of coils at high decoupling power levels applied during 13C reception. Peak decoupler RF power deposition in tissue was computed numerically from electromagnetic theory assuming a semi-infinite plane of uniform biological conductor. Peak values at the surface were calculated at 4 to 6 W/kg in any gram of tissue for each watt of decoupler power input excluding all coil and cable losses, warning of potential local RF heating problems in these and related experiments. The average power deposition was about 9 mW/kg per watt input, which should present no systemic hazard. At 3 W input, human 13C spectra were decoupled to a depth of about 5 cm while some Overhauser enhancement was sustained up to about 3 cm depth, without ill effect. The observation of glycogen in localized natural abundance 13C spectra of heart and muscle suggests that metabolites in the citric acid cycle should be observable noninvasively using 13C-labeled substrates.},
doi = {10.1002/mrm.1910120307},
url = {https://www.osti.gov/biblio/7137761},
journal = {Magnetic Resonance in Medicine; (USA)},
issn = {0740-3194},
number = ,
volume = 12:3,
place = {United States},
year = {Fri Dec 01 00:00:00 EST 1989},
month = {Fri Dec 01 00:00:00 EST 1989}
}