Journal ArticleDOI
In vivo proton spectroscopy in presence of eddy currents
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TLDR
A correction method is proposed for proton spectroscopy, which uses the signal of prominent water protons as a reference for the water‐suppressed signal, and has a good resolution as shown by phantom measurements and brain and muscle spectra of volunteers.Abstract:
Spatially localized methods in spectroscopy often operate with magnetic field gradients for volume selection. The eddy currents induced by these gradients produce time-dependent shifts of the resonance frequency in the selected volume, which results in a distortion of the spectrum after Fourier transformation. In whole-body systems the complete compensation of eddy currents is a difficult procedure. To avoid this, a correction method is proposed for proton spectroscopy, which uses the signal of prominent water protons as a reference for the water-suppressed signal. The correction is performed in the time domain, dividing the water-suppressed signal by the phase factor of the water signal for each data point. The corrected spectra have a good resolution as shown by phantom measurements and brain and muscle spectra of volunteers.read more
Citations
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Journal ArticleDOI
Estimation of metabolite concentrations from localized in vivo proton NMR spectra
TL;DR: The LCModel method analyzes an in vivo spectrum as a Linear Combination of Model spectra of metabolite solutions in vitro by using complete model spectra, rather than just individual resonances, to ensure maximum information and uniqueness are incorporated into the analysis.
Patent
Magnetic resonance imaging device
TL;DR: By using a multiple receiving coil composed of receiving coils, an imaging portion of a subject is subjected to a first pulse sequence to create n sensitivity images (701 to 703) fewer than the examination images as discussed by the authors.
Journal ArticleDOI
Metabolic profiles of human brain tumors using quantitative in vivo 1H magnetic resonance spectroscopy.
Franklyn A. Howe,S. J. Barton,Simon Cudlip,Marion Stubbs,Dawn E. Saunders,Mary Murphy,Peter R. Wilkins,Kirstie S. Opstad,V. L. Doyle,Mary A. McLean,B. A. Bell,John R. Griffiths +11 more
TL;DR: Proton spectroscopy can noninvasively provide useful information on brain tumor type and grade, and quantified lipid, macromolecule, and lactate levels increased with grade of tumor, consistent with progression from hypoxia to necrosis.
Journal ArticleDOI
Regional metabolite concentrations in human brain as determined by quantitative localized proton MRS.
Petra J. W. Pouwels,Jens Frahm +1 more
TL;DR: The present findings neither support a metabolic gender difference (except for a 1.3‐fold higher myo‐inositol level in parietal white matter of female subjects) nor a metabolic hemispheric asymmetry.
Journal ArticleDOI
1H MR Spectroscopy of the Brain: Absolute Quantification of Metabolites
TL;DR: Important methodological aspects in an absolute quantification strategy are addressed, including radiofrequency coil properties, calibration procedures, spectral fitting methods, cerebrospinal fluid content correction, macromolecule suppression, and spectral editing.
References
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Journal ArticleDOI
Localized high-resolution proton NMR spectroscopy using stimulated echoes: initial applications to human brain in vivo.
Jens Frahm,Harald Bruhn,Michael L. Gyngell,Klaus-Dietmar Merboldt,Wolfgang Hänicke,R. Sauter +5 more
TL;DR: Water‐suppressed localized proton NMR spectroscopy using stimulated echoes has been successfully applied to detect metabolites in the human brain in vivo and Cerebral lactate was found to be at a maximum concentration of 0.5 mM.
Journal ArticleDOI
The correction of transient b0 field shifts following the application of pulsed gradients by phase correction in the time domain
Roger J. Ordidge,I.D Cresshull +1 more
TL;DR: La methode est utilisee dans la restauration de spectres haute resolution obtenus a partir de volumes localises par l'utilisation de gradients de champs magnetiques et d'impulsions radiofrequences selectives.
Journal ArticleDOI
Human breast cancer in vivo: H-1 and P-31 MR spectroscopy at 1.5 T.
TL;DR: To assess the potential of in vivo magnetic resonance (MR) spectroscopy for breast cancer, hydrogen-1 and phosphorus-31 MR spectra of five malignant human breast tumors were compared with those of unaffected breast tissue and an intense phosphocreatine signal was observed.
Journal ArticleDOI
Compensation of instrumental imperfections by deconvolution using an internal reference signal
Journal ArticleDOI
Whole-body MR imaging and spectroscopy with a 4-T system.
TL;DR: In sodium imaging, the high flux density appears to be useful in reducing imaging time, which should increase the usefulness of sodium imaging in evaluating brain tumors and strokes, and in spectroscopy, the increase in flux density improves the quality of the spectra.