Relaxation Enhancement by Longitudinal Multispin Orders

Loyola D'Silva¹, S. Sendhil Velan¹

There is a great interest in increasing the longitudinal relaxation of nuclear spins for hyperpolarized imaging experiments. Longitudinal multispin orders (LOMO) correspond to the non-equilibrium population distribution and can be created in spin systems that exhibit J couplings, dipolar couplings or quadrupolar couplings. It can also be created via cross-correlated relaxation between different relaxation pathways present for the given spin system. A two fold increase in longitudinal magnetization is achieved using the frequency cycling approach.