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Quantifying 1 H decoupled in vivo 31 P brain spectra
Author(s) -
Potwarka John J.,
Drost Dick J.,
Williamson Peter C.
Publication year - 1999
Publication title -
nmr in biomedicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.278
H-Index - 114
eISSN - 1099-1492
pISSN - 0952-3480
DOI - 10.1002/(sici)1099-1492(199902)12:1<8::aid-nbm540>3.0.co;2-#
Subject(s) - spectral line , in vivo , standard deviation , metabolite , nuclear magnetic resonance , physics , chemistry , mathematics , analytical chemistry (journal) , statistics , chromatography , biology , biochemistry , microbiology and biotechnology , astronomy
Our objective was to develop a precise method for quantification of in vivo proton decoupled 31 P spectra from the human brain. This objective required that an appropriate spectral model be created and that the quantification was performed using a non‐subjective fitting technique. The precision of the quantification was assessed using Cramér–Rao standard deviations and compared using two different spectral models: one containing a pair of peaks representing 2,3‐diphosphoglycerate, the other excluding this metabolite. The data was quantified using a Marquardt–Levenberg (ML) algorithm incorporating prior knowledge with a Hankel singular value decomposition (HSVD) performed initially to provide parameter estimates for the ML algorithm. Quantification was performed on two different in vivo 2‐D CSI 31 P data sets: the first examined 11 normal controls, the second examined a single individual six times. Spectra from a region in the parieto‐occipital cortex were analyzed. The Cramér–Rao standard deviations were significantly lower for some metabolites with 2,3‐diphosphoglycerate in the model: in the repeat study mobile phospholipids ( p = 0.045) and phosphocholine ( p = 0.034), and in the 11 controls mobile phospholipids ( p = 0.003) and P i ( p = 0.002). Copyright © 1999 John Wiley & Sons, Ltd.