Variable Density K-space Trajectories for Reducing Aliasing Artifacts in MRI Reconstruction

As is well known, the energy of an image is mostly concentrated in the low frequency components of k-space. In this paper, variable density Cartesian trajectory and variable density square spiral trajectory are proposed, oversampling the low frequency area while undersampling the high frequency area in k-space, in order to respectively reduce the aliasing artifact and shorten the scan time. Experimental results illustrated that aliasing artifact is almost imperceptible due to low frequency components oversampling and scan time is shortened due to high frequency area undersampling