Figure 5.

Demonstration of improved temporal resolution using sparse sampling and constrained reconstruction: A speech task of repeated counting of numbers “one-two-three-four-five” at a normal pace followed by a rapid pace (∼4 times faster) was performed. The top and bottom rows show the comparisons against Nyquist spiral sampling and gridding reconstruction with the 2.4 mm² and 1.76 mm² sequences respectively, where the time profiles corresponds to the cut marked by the white arrow in the spatial frames (first column). Note the marked improvement in the temporal fidelity (in terms of crispness along time profiles) of the accelerated reconstructions in comparison with the fully sampled reconstructions. As demonstrated in the last column, the gains in time resolution ensure the capture of fast articulatory movements.