initialize_3D_park_radial#

mrinufft.trajectories.inits.radial.initialize_3D_park_radial(Nc: int, Ns: int, nb_interleaves: int = 1, in_out: bool = False) → ndarray[tuple[int, ...], dtype[_ScalarType_co]][source]#

Initialize 3D radial trajectories with a spiral structure.

The radial shots are oriented according to an archimedean spiral over a sphere surface, shared uniformly between all interleaves.

This function reproduces the proposition from [Par+16], itself based on the work from [WR94], with in addition the option to switch between center-out and in-out radial shots.

Parameters:

  • Nc (int) – Number of shots

  • Ns (int) – Number of samples per shot

  • nb_interleaves (int, optional) – Number of implicit interleaves defining the shots order for a more structured k-space distribution over time, by default 1

  • in_out (bool, optional) – Whether the curves are going in-and-out or start from the center, by default False

Returns:

3D Park radial trajectory

Return type:

NDArray

References

[Par+16]

Park, Jinil, Taehoon Shin, Soon Ho Yoon, Jin Mo Goo, and Jang-Yeon Park. “A radial sampling strategy for uniform k-space coverage with retrospective respiratory gating in 3D ultrashort-echo-time lung imaging.” NMR in Biomedicine 29, no. 5 (2016): 576-587.