Journal ArticleDOI
Automated spectral analysis III: application to in vivo proton MR spectroscopy and spectroscopic imaging
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TLDR
The automated fitting procedure was applied to four different examples of MRS data obtained at 1.5 T and 4.1 T and was shown to perform reliably even in the presence of large baseline signals and relatively poor signal‐to‐noise ratios typical of in vivo proton MRSI.Abstract:
An automated method for analysis of in vivo proton magnetic resonance (MR) spectra and reconstruction of metabolite distributions from MR spectroscopic imaging (MRSI) data is described. A parametric spectral model using acquisition specific, a priori information is combined with a wavelet-based, nonparametric characterization of baseline signals. For image reconstruction, the initial fit estimates were additionally modified according to a priori spatial constraints. The automated fitting procedure was applied to four different examples of MRS data obtained at 1.5 T and 4.1 T. For analysis of major metabolites at medium TE values, the method was shown to perform reliably even in the presence of large baseline signals and relatively poor signal-to-noise ratios typical of in vivo proton MRSI. Identification of additional metabolites was also demonstrated for short TE data. Automated formation of metabolite images will greatly facilitate and expand the clinical applications of MR spectroscopic imaging.read more
Citations
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Journal ArticleDOI
Proton NMR chemical shifts and coupling constants for brain metabolites.
TL;DR: Proton NMR chemical shift and J‐coupling values are presented for 35 metabolites that can be detected by in vivo or in vitro NMR studies of mammalian brain, with an accuracy suitable for computer simulation of metabolite spectra to be used as basis functions of a parametric spectral analysis procedure.
Journal ArticleDOI
Toward an in Vivo Neurochemical Profile: Quantification of 18 Metabolites in Short-Echo-Time 1H NMR Spectra of the Rat Brain
TL;DR: Frequency domain analysis with LCModel showed that the in vivo spectra can be explained by 18 metabolite model solution spectra and a highly structured background, which was attributed to resonances with fivefold shorter in vivo T(1) than metabolites.
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.
Journal ArticleDOI
Issues of spectral quality in clinical 1H-magnetic resonance spectroscopy and a gallery of artifacts
TL;DR: This article aims to increase interest in issues of spectral quality and quality assessment, to start a larger debate on generally accepted criteria that spectra must fulfil to be clinically and scientifically acceptable, and to provide a sample gallery of artifacts, which can be used to raise awareness for potential pitfalls in MRS.
Journal ArticleDOI
Time-domain semi-parametric estimation based on a metabolite basis set.
Hélène Ratiney,Michaël Sdika,Y. Coenradie,Y. Coenradie,Sophie Cavassila,D. van Ormondt,Danielle Graveron-Demilly +6 more
TL;DR: Three novel semi‐parametric approaches to handle 1H short echo‐time signals in terms of bias‐variance trade‐off are proposed and tested and valuable insight about quantitation precision is obtained from the correlation matrices.
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