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Least‐squares chemical shift separation for 13 C metabolic imaging
Author(s) -
Reeder Scott B.,
Brittain Jean H.,
Grist Thomas M.,
Yen YiFen
Publication year - 2007
Publication title -
journal of magnetic resonance imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.563
H-Index - 160
eISSN - 1522-2586
pISSN - 1053-1807
DOI - 10.1002/jmri.21089
Subject(s) - metabolite , imaging phantom , signal (programming language) , nuclear magnetic resonance , chemical species , signal to noise ratio (imaging) , alanine , separation (statistics) , chemistry , analytical chemistry (journal) , biological system , computer science , physics , chromatography , optics , biology , biochemistry , organic chemistry , amino acid , machine learning , programming language
Purpose To describe a new least‐squares chemical shift (LSCSI) method for separation of chemical species with widely spaced peaks in a sparse spectrum. The ability to account for species with multiple peaks is addressed. Materials and Methods This method is applied to imaging of 13 C‐labeled pyruvate and its metabolites alanine, pyruvate, and lactate. The method relies on a priori knowledge of the resonant frequencies of the different chemical species, as well as the relative signal from the two pyruvate peaks, one of which lies near the alanine peak. With this information a least‐squares method was utilized for separation of signal from the three metabolites, facilitating tremendous reductions in the amount of data required to decompose the different chemical species. Optimization of echo spacing for maximum noise performance of the signal separation is also described. Results Imaging an enriched 13 C phantom at 3.0T, the LSCSI method demonstrates excellent metabolite separation, very similar to echo planar spectroscopic imaging (EPSI), while only using 1/16th as much data. Conclusion This approach may be advantageous for in vivo hyperpolarized 13 C metabolic applications for reduced scan time compared with EPSI. J. Magn. Reson. Imaging 2007;26:1145–1152. © 2007 Wiley‐Liss, Inc.