Four-shot non-cartesian trajectories for k-space sampling in MRI

This paper considers the problem of designing trajectories for scanning k-space in MRI. Various cartesian and non-cartesian trajectories such as rectangular, spiral, radial, etc. have been proposed in the literature. Non-cartesian trajectories are observed to perform optimally in terms of scan time and reduced artifacts in the constructed image. Novel k-space sampling trajectories that use sinusoidal smooth functions and four RF excitations (four-shots) have been proposed here. Simulations on Shepp–Logan phantom image show that the proposed trajectory provides slightly better peak signal-to-noise ratio compared to the commonly used spiral trajectory .