initialize_3D_floret

initialize_3D_floret#

mrinufft.trajectories.trajectory3D.initialize_3D_floret(Nc, Ns, in_out=False, nb_revolutions=1, spiral='fermat', cone_tilt='golden', max_angle=1.5707963267948966, axes=(2,))[source]#

Initialize 3D trajectories with FLORET.

This implementation is based on the work from [Pip+11]. The acronym FLORET stands for Fermat Looped, Orthogonally Encoded Trajectories. It consists of Fermat spirals folded into 3D cones along one or several axes.

Parameters:

  • Nc (int) – Number of shots

  • Ns (int) – Number of samples per shot

  • in_out (bool, optional) – Whether to start from the center or not, by default False

  • nb_revolutions (float, optional) – Number of revolutions of the spirals, by default 1

  • spiral (str, float, optional) – Spiral type, by default “fermat”

  • cone_tilt (str, float, optional) – Tilt of the cones around the \(k_z\)-axis, by default “golden”

  • max_angle (float, optional) – Maximum polar angle starting from the \(k_x-k_y\) plane, by default pi / 2

  • axes (tuple, optional) – Axes over which cones are created, by default (2,)

Returns:

3D FLORET trajectory

Return type:

array_like

References

[Pip+11]

Pipe, James G., Nicholas R. Zwart, Eric A. Aboussouan, Ryan K. Robison, Ajit Devaraj, and Kenneth O. Johnson. “A new design and rationale for 3D orthogonally oversampled k‐space trajectories.” Magnetic resonance in medicine 66, no. 5 (2011): 1303-1311.