SPATIAL LOCALIZATION IN STOCHASTIC NMR IMAGING WITH OSCILLATING GRADIENTS

A technique for spectroscopic imaging employing oscillating gradients for spatial encoding in conjunction with a stochastic RF excitation is proposed and analyzed. Localization functions are derived for a linearized model and compared with Bloch equation simulations. An implementation of the technique is described, and experimental point spread functions and a spectroscopic image (one spatial dimension and one chemical shift) are presented. Advantages of the technique are a large reduction in the peak RF power required relative to conventional pulse excitation and the elimination of switching transients through the use of oscillating gradients. Spectroscopic resolution and T2 contrast maybe varied by postprocessing a single experimental data set. © 1990.