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initialize_3D_helical_shells

initialize_3D_helical_shells#

mrinufft.trajectories.trajectory3D.initialize_3D_helical_shells(Nc, Ns, nb_shells, spiral_reduction=1, shell_tilt='intergaps', shot_tilt='uniform')[source]#

Initialize 3D trajectories with helical shells.

The implementation follows the proposition from [YRB06] but the idea can be traced back much further [IN95].

Parameters:

  • Nc (int) – Number of shots

  • Ns (int) – Number of samples per shot

  • nb_shells (int) – Number of concentric shells/spheres

  • spiral_reduction (float) – Factor used to reduce the automatic spiral curvature, by default 1

  • shell_tilt (str, float, optional) – Angle between consecutive shells along z-axis, by default “intergaps”

  • shot_tilt (str, float, optional) – Angle between shots over a shell surface along z-axis, by default “uniform”

Returns:

3D helical shell trajectory

Return type:

array_like

References

[YRB06]

Shu, Yunhong, Stephen J. Riederer, and Matt A. Bernstein. “Three‐dimensional MRI with an undersampled spherical shells trajectory.” Magnetic Resonance in Medicine 56, no. 3 (2006): 553-562.

[IN95]

Irarrazabal, Pablo, and Dwight G. Nishimura. “Fast three dimensional magnetic resonance imaging.” Magnetic Resonance in Medicine 33, no. 5 (1995): 656-662

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