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Exchange‐linked dissolution agents in dissolution‐DNP 13 C metabolic imaging
Author(s) -
Hurd Ralph E.,
Spielman Daniel,
Josan Sonal,
Yen YiFen,
Pfefferbaum Adolf,
Mayer Dirk
Publication year - 2013
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.24544
Subject(s) - dissolution , chemistry , sodium , sodium lactate , bolus (digestion) , medicine , organic chemistry
Purpose The use of unlabeled exchange‐linked dissolution agents in hyperpolarized metabolic imaging was studied to examine pool size limits and saturation relative to the availability of NADH. Methods Three‐dimensional dynamic metabolic images were obtained, and compared following injection of a bolus of hyperpolarized [1‐ 13 C]pyruvate, prepared with and without unlabeled sodium lactate in the dissolution buffer. Comparisons were made on the basis of apparent rate constants and [1‐ 13 C]lactate signal‐to‐noise ratio. Range finding data were obtained for different bolus compositions. Isotope exchange was also probed in the reverse direction, following injection of a bolus of hyperpolarized [1‐ 13 C]lactate, with and without unlabeled sodium pyruvate in the dissolution buffer. Results Liver, kidney, and vascular regions of interest all showed an increase in [1‐ 13 C]lactate signal with addition of unlabeled sodium lactate in the dissolution buffer. Injection of hyperpolarized [1‐ 13 C]lactate with unlabeled sodium pyruvate in the dissolution buffer, provided exchange rate constants K lp for kidney and vascular regions of interest. Conclusions These results are consistent with a high level of 13 C‐exchange, and with labeling rates that are limited by steady‐state pool sizes in vivo. Magn Reson Med, 70:936–942, 2013. © 2012 Wiley Periodicals, Inc.