title: Hyperpolarized (1)H NMR employing low gamma nucleus for spin polarization storage.
abstract: Here, we demonstrate the utility of low gamma nuclei for spin storage of hyperpolarization followed by proton detection, which theoretically can provide up to approximately (gamma[1H]/gamma[X])(2) gain in sensitivity in hyperpolarized biomedical MR. This is exemplified by hyperpolarized 1-(13)C sites of 2,2,3,3-tetrafluoropropyl 1-(13)C-propionate-d(3) (TFPP), (13)C T(1) = 67 s in D(2)O, and 1-(13)C-succinate-d(2), (13)C T(1) = 105 s in D(2)O, pH 11, using PASADENA. In a representative example, the spin polarization was stored on (13)C for 24 and 70 s, respectively, while the samples were transferred from a low magnetic field polarizer operating at 1.76 mT to a 4.7 T animal MR scanner. Following sample delivery, the refocused INEPT pulse sequence was used to transfer spin polarization from (13)C to protons with an efficiency of 50% for TFPP and 41% for 1-(13)C-succinate-d(2) increasing the overall NMR sensitivity by a factor of 7.9 and 6.5, respectively. The low gamma nuclei exemplified here by (13)C with a T(1) of tens of seconds acts as an efficient spin polarization storage, while J-coupled protons are better for NMR detection.
authors.affiliation: Enhanced Magnetic Resonance Laboratory, Huntington Medical Research Institutes, Pasadena, California 91105, USA.
authors.forename: Eduard Y
authors.initials: EY
authors.lastname: Chekmenev
authors.forename: Valerie A
authors.initials: VA
authors.lastname: Norton
authors.forename: Daniel P
authors.initials: DP
authors.lastname: Weitekamp
authors.forename: Pratip
authors.initials: P
authors.lastname: Bhattacharya
mesh_terms: D000179:Acrylates / Q000737:chemistry; D002247:Carbon Isotopes; D005650:Fumarates / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000592:standards; D011422:Propionates / Q000138:chemical synthesis / Q000737:chemistry; D011522:Protons; D012015:Reference Standards; D019802:Succinic Acid / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D000179:Acrylates; D002247:Carbon Isotopes; D005650:Fumarates; D011422:Propionates; D011522:Protons; D006859:Hydrogen; D019802:Succinic Acid