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, optional) – Factor used to reduce the automatic spiral length, 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