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Automated transfer and injection of hyperpolarized molecules with polarization measurement prior to in vivo NMR

Automated transfer and injection of hyperpolarized molecules with polarization measurement prior to in vivo NMR

Authors :
Patrick Hautle
Mor Mishkovsky
Jessica A. M. Bastiaansen
Paul Tordo
Olivier Ouari
Tian Cheng
Arnaud Comment
Ben van den Brandt
Source :
NMR in Biomedicine. 26:1582-1588
Publication Year :
2013
Publisher :
Wiley, 2013.

Abstract

yperpolarized magnetic resonance via dissolution dynamic nuclear polarization necessitates the transfer of thehyperpolarized molecules from the polarizer to the imager prior to in vivo measurements. This process leads to unavoid-able losses in nuclear polarization, which are difficult to evaluate once the solution has been injected into an animal. Wepropose a method to measure the polarization of the hyperpolarized molecules inside the imager bore, 3 s following dis-solution, at the time of the injection, using a precise quantification of the infusate concentration. This in situ quantifica-tion allows for distinguishing between signal modulations related to variations in the nuclear polarization at the time ofthe injection and signal modulations related to physiological processes such as tissue perfusion. In addition, our methodincludes a radical scavenging process that leads to a minor reduction in sample concentration and takes place within acouple of seconds following the dissolution in order to minimize the losses due to the presence of paramagnetic polar-izing agent in the infusate. We showed that proton exchange between vitamin C, the scavenging molecule and the deu-terated solvent shortens the long carboxyl13C longitudinal relaxation time in [1-13C]acetate. This additional source ofdipolar relaxation can be avoided by using deuterated ascorbate. Overall, the method allows for a substantial gain inpolarization and also leads to an extension of the time window available for in vivo measurements.

Details

ISSN :
09523480
Volume :
26
Database :
OpenAIRE
Journal :
NMR in Biomedicine
Accession number :
edsair.doi...........1692bd67bb4f7196641e65c87dbed74d
Full Text :
https://doi.org/10.1002/nbm.2993