Block regional interpolation scheme for k-space (BRISK): a rapid cardiac imaging technique.

We introduce an acquisition method, "block regional interpolation scheme for k-space" (BRISK), to reduce the acquisition time for cardiac imaging. The method exploits the high degree of correlation that exists between time-resolved cardiac images. For representative k-space data sets, Fourier analysis was applied along the cardiac phase dimension to reveal that different regions of k-space can be effectively sampled at different rates. A reduced sampling strategy was implemented, and unsampled points were generated by Fourier interpolation. Time savings of up to 75% are quite feasible and 25% BRISK scans compare well with 100% scans. Simulations and acquisitions using a normal volunteer and patients are presented.