Fast acquisition and sampling in MRI: Introduction to time-sequential sampling of spatio-temporal signals

Dynamic MRI is formulated as the reconstruction of a spatiotemporal signal from samples of its spatial Fourier transform in (k,t)-space. The sampling strategy, which defines the acquisition procedure, is subject to an inherent time-sequential sampling (TSS) constraint: only one sample in k-space can be acquired at any one time. We use our recently introduced TSS theory to develop adaptive minimum redundancy data acquisition and reconstruction procedures optimized for the dynamic object being imaged. The approach can produce a high temporal and spatial resolution movie of the dynamic object, with multifold reduction in acquisition rate compared to conventional methods.