spiral.m

2D imaging sequence with spiral k-space sampling; it must be called from the imaging.m context, which provides H,R,K,G, and F, and before Fourier transformation the spiral trajectory is resampled onto a square k-space grid.

Syntax

    mri=spiral_pulse_sequence(spin_system,parameters,H,R,K,G,F)

Parameters

     parameters.t_echo     - echo time, seconds

     parameters.spiral_frq - angular frequency of the spiral, rad/s 

     parameters.spiral_dur - duration of the spiral, seconds

     parameters.grad_amp   - gradient amplitude at the end 
                             of the spiral, T/m

Outputs

    mri - MRI image with square sinebell apodisation

Examples

See spiral_2d.m file in examples/imaging directory.

Notes

Prior to being Fourier transformed, the spiral is resampled onto a suitable square k-space grid - change the sequence to output spiral_kx, spiral_ky and spiral_z variables if you plan to process the data in a different way.

See also

phase_enc_2d.m, epi_2d.m, fse.m, imaging.m, basic_1d_hard.m, cpmg_dec.m, epi_3d.m, grad_echo.m, phase_enc_3d.m, press_1d.m, press_2d.m, press_voxel_1d.m, press_voxel_2d.m, press_voxel_3d.m, slice_select_1d.m, spin_echo.m, udd_dec.m, uhrig_times.m, Built-in_experiments, Imaging_module, Mri_sequence_list

Version 2.1, authors: Ilya Kuprov, Ahmed Allami