IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
artículos
Título:
Magnetic resonance imaging of 1 H long lived states derived from parahydrogen induced polarization in a clinical system
Autor/es:
DIRK GRAAFEN; FRANZONI, M.B.; LAURA M. SCHREIBER; HANS W. SPIESS; KERSTIN MÜNNEMANN
Revista:
JOURNAL OF MAGNETIC RESONANCE
Editorial:
ACADEMIC PRESS INC ELSEVIER SCIENCE
Referencias:
Lugar: Amsterdam; Año: 2015 vol. 262
ISSN:
1090-7807
Resumen:
Hyperpolarization is a powerful tool to overcome the low sensitivity of nuclear magnetic resonance (NMR). However, applications are limited due to the short lifetime of this non equilibrium spin state caused  by  relaxation  processes.  This  issue  can  be  addressed  by  storing  hyperpolarization  in  slowly decaying  singlet  spin  states  which  was  so  far  mostly  demonstrated  for  non-proton  spin  pairs,  e.g. 13 C? 13 C. Protons hyperpolarized by parahydrogen induced polarization (PHIP) in symmetrical molecules, are  very  well  suited  for  this  strategy  because  they  naturally  exhibit  a  long-lived  singlet  state.  The conversion of the NMR silent singlet spin state to observable magnetization can be achieved by making use of singlet?triplet level anticrossings. In this study, a low-power radiofrequency pulse sequence is used  for  this  purpose,  which  allows  multiple  successive  singlet?triplet  conversions.  The  generated magnetization is used to record proton images in a clinical magnetic resonance imaging (MRI) system, after 3 min waiting time. Our results may open unprecedented opportunities to use the standard MRInucleus 1 H for e.g. metabolic imaging in the future.