TY - JOUR
T1 - On neglecting chemical exchange when correcting in vivo 31 P MRS data for partial saturation
T2 - Commentary on: "Pitfalls in the measurement of metabolite concentrations using the one-pulse experiment in in vivo NMR"
AU - Ouwerkerk, Ronald
AU - Bottomley, Paul A.
N1 - Funding Information:
1Supported by NIH Grants R01 HL56882-01, R01-HL61912-01, and R21 HL62332-01.
PY - 2001
Y1 - 2001
N2 - This article replies to Spencer et al. (J. Magn. Reson. 149, 251-257, 2001) concerning the degree to which chemical exchange affects partial saturation corrections using saturation factors. Considering the important case of in vivo 31 P NMR, we employ differential analysis to demonstrate a broad range of experimental conditions over which chemical exchange minimally affects saturation factors, and near-optimum signal-to-noise ratio is preserved. The analysis contradicts Spencer et al.'s broad claim that chemical exchange results in a strong dependence of saturation factors upon M 0 's and T 1 and exchange parameters. For Spencer et al.'s example of a dynamic 31 P NMR experiment in which phosphocreatine varies 20-fold, we show that our strategy of measuring saturation factors at the start and end of the study reduces errors in saturation corrections to 2% for the high-energy phosphates.
AB - This article replies to Spencer et al. (J. Magn. Reson. 149, 251-257, 2001) concerning the degree to which chemical exchange affects partial saturation corrections using saturation factors. Considering the important case of in vivo 31 P NMR, we employ differential analysis to demonstrate a broad range of experimental conditions over which chemical exchange minimally affects saturation factors, and near-optimum signal-to-noise ratio is preserved. The analysis contradicts Spencer et al.'s broad claim that chemical exchange results in a strong dependence of saturation factors upon M 0 's and T 1 and exchange parameters. For Spencer et al.'s example of a dynamic 31 P NMR experiment in which phosphocreatine varies 20-fold, we show that our strategy of measuring saturation factors at the start and end of the study reduces errors in saturation corrections to 2% for the high-energy phosphates.
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U2 - 10.1006/jmre.2001.2286
DO - 10.1006/jmre.2001.2286
M3 - Editorial
C2 - 11318631
AN - SCOPUS:0035742164
VL - 149
SP - 282
EP - 286
JO - Journal of Magnetic Resonance
JF - Journal of Magnetic Resonance
SN - 1090-7807
IS - 2
ER -