Quality assurance of PASADENA hyperpolarization for 13C biomolecules.
OBJECTIVE
Define MR quality assurance procedures for maximal PASADENA hyperpolarization of a biological (13)C molecular imaging reagent.


METHODS
An automated PASADENA polarizer and a parahydrogen generator were installed. (13)C enriched hydroxyethyl acrylate, 1-(13)C, 2,3,3-d(3) (HEA), was converted to hyperpolarized hydroxyethyl propionate, 1-(13)C, 2,3,3-d(3) (HEP) and fumaric acid, 1-(13)C, 2,3-d(2) (FUM) to hyperpolarized succinic acid, 1-(13)C, 2,3-d(2) (SUC), by reaction with parahydrogen and norbornadiene rhodium catalyst. Incremental optimization of successive steps in PASADENA was implemented. MR spectra and in vivo images of hyperpolarized (13)C imaging agents were acquired at 1.5 and 4.7 T.


RESULTS
Application of quality assurance (QA) criteria resulted in incremental optimization of the individual steps in PASADENA implementation. Optimal hyperpolarization of HEP of P = 20% was achieved by calibration of the NMR unit of the polarizer (B (0) field strength +/- 0.002 mT). Mean hyperpolarization of SUC, P = [15.3 +/- 1.9]% (N = 16) in D (2)O, and P = [12.8 +/- 3.1]% (N = 12) in H (2)O, was achieved every 5-8 min (range 13-20%). An in vivo (13)C succinate image of a rat was produced.


CONCLUSIONS
PASADENA spin hyperpolarization of SUC to 15.3% in average was demonstrated (37,400 fold signal enhancement at 4.7 T). The biological fate of (13)C succinate, a normally occurring cellular intermediate, might be monitored with enhanced sensitivity.
Hövener
Jan-Bernd
JB
Enhanced Magnetic Resonance Laboratory, Huntington Medical Research Institutes, Pasadena, CA 91105, USA.
Chekmenev
Eduard Y
EY
Harris
Kent C
KC
Perman
William H
WH
Tran
Thao T
TT
Ross
Brian D
BD
Bhattacharya
Pratip
P
D001704:Biopolymers / Q000032:analysis*; D002247:Carbon Isotopes / Q000032:analysis*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000592:standards*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000592:standards*; D011785:Quality Assurance, Health Care; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014481:United States
D001704:Biopolymers; D002247:Carbon Isotopes