Kinetics of heteronuclear cross-relaxation in dipolar coupled-spin systems: Applications to in vivo measurements

摘要

abstract_textpSignal intensity changes observed in double-resonance experiments on dipolar coupled-spin systems in liquid phase are known as the nuclear Overhauser effect (NOE). This article describes the theory of dynamic nuclear polarization of coupled spin-1/2 nuclei along with the experimental techniques that permit us to observe the kinetics of heteronuclear NOE and that help us to determine the cross-relaxation rate constant. Kinetic effects can be detected in coupled I-S spin ensembles when the period of driving of S spins is varied and the nuclear magnetic resonance signal enhancement of I spins is recorded. Truncated driven and transient NOE experiments on P-31-H-1 and C-13-H-1 spin systems are discussed with particular reference to in vivo applications. (C) 1997 John Wiley Sons, Inc./p/abstract_text