mrpro.data.traj_calculators.KTrajectoryRpe

class mrpro.data.traj_calculators.KTrajectoryRpe[source]

Bases: KTrajectoryCalculator

Radial phase encoding trajectory.

Frequency encoding along kx is carried out in a standard Cartesian way. The phase encoding points along ky and kz are positioned along radial lines [BOU2009] [KOL2014].

References

[BOU2009]

Boubertakh R, Schaeffter T (2009) Whole-heart imaging using undersampled radial phase encoding (RPE) and iterative sensitivity encoding (SENSE) reconstruction. MRM 62(5) https://doi.org/10.1002/mrm.22102

[KOL2014]

Kolbitsch C, Schaeffter T (2014) A 3D MR-acquisition scheme for nonrigid bulk motion correction in simultaneous PET-MR. Medical Physics 41(8) https://doi.org/10.1118/1.4890095

__init__(angle: float, shift_between_rpe_lines: tuple | Tensor = (0, 0.5, 0.25, 0.75)) → None[source]

Initialize KTrajectoryRpe.

Parameters:

  • angle (float) – angle in rad between two radial phase encoding lines

  • shift_between_rpe_lines (tuple | Tensor, default: (0, 0.5, 0.25, 0.75)) – shift between radial phase encoding lines along the radial direction. See _apply_shifts_between_rpe_lines() for more details

__call__(*, n_k0: int, k0_center: int | Tensor, k1_idx: Tensor, k1_center: int | Tensor, k2_idx: Tensor, reversed_readout_mask: Tensor | None = None, **_) → KTrajectory[source]

Calculate radial phase encoding trajectory for given header information.

Parameters:

  • n_k0 (int) – number of samples in k0

  • k0_center (int | Tensor) – position of k-space center in k0

  • k1_idx (Tensor) – indices of k1

  • k1_center (int | Tensor) – position of k-space center in k1

  • k2_idx (Tensor) – indices of k2

  • reversed_readout_mask (Tensor | None, default: None) – boolean tensor indicating reversed readout

Returns:

radial phase encoding trajectory for given header information

__eq__(value, /)

Return self==value.

__new__(**kwargs)