Localized 13C-[1H] NMR of rat liver in vivo using surface-spoiling gradients.

An NMR spectroscopy localization method that employs an inhomogeneous surface-spoiling magnetic field gradient has been applied to detect the 13C-[1H] signals from deep-lying liver tissue of rat in vivo. The method requires small gradient driving currents (less than 1 amp) and short gradient periods (approximately 0.5-1.6 ms). Thus, it is not likely to suffer from induced eddy currents and can detect short T2 resonances. We demonstrate that by employing a pulsed surface-spoiling gradient one can eliminate "contaminating" signals from the surface-lying tissues (muscle, fat and skin) while still maintaining the resonance linewidth resolution for the deep-lying tissue of interest (liver). The feasibility of using this localization approach to trace glucose conversion into glycogen is shown.