Elimination of nyquist ghosts in MRI by using fast linogram imaging

Abstract

Timing inaccuracies between the even and odd echoes lead to the formation of Nyquist ghosts in conventional (blipped) echo-planar imaging (EPI). A fast radial scanning method based on the linogram sampling geometry was designed and implemented. No ghosting effects are seen with this scheme, and correction for timing inaccuracies is performed using simple postprocessing steps before reconstruction.

Applying the uniform resampling (URS) algorithm to a lissajous trajectory: Fast image reconstruction with optimal gridding

“…Various kinds of k-space trajectories, such as spirals (1)(2)(3), circles (4), rosettes (5), linogram (6), and stochastic patterns (7), have been studied during the development of nonrectilinear Cartesian data sampling methods. When these trajectories are used, most of the image reconstruction methods require gridding before the 2D-FFT can be performed, since the sampled data are not usually located on a rectilinear Cartesian grid in k-space.…”