pulpy.rf.ptx.stspk

pulpy.rf.ptx.stspk(mask, sens, n_spokes, fov, dx_max, gts, sl_thick, tbw, dgdtmax, gmax, alpha=1, iter_dif=0.01)[source]

Small tip spokes parallel transmit pulse designer.

Parameters:

  • mask (ndarray) – region in which to optimize flip angle uniformity in slice. [dim dim]

  • sens (ndarray) – sensitivity maps. [nc dim dim]

  • n_spokes (int) – number of spokes to be created in the design.

  • fov (float) – excitation FOV (cm).

  • dx_max (float) – max. resolution of the trajectory (cm).

  • gts (float) – hardware sampling dwell time (s).

  • sl_thick (float) – slice thickness (mm).

  • tbw (int) – time-bandwidth product.

  • dgdtmax (float) – max gradient slew (g/cm/s).

  • gmax (float) – max gradient amplitude (g/cm).

  • alpha (float) – regularization parameter.

  • iter_dif (float) – for each spoke, the difference in cost btwn. successive iterations at which to terminate MLS iterations.

Returns:

2-element tuple containing

  • pulses (array): RF waveform out.

  • g (array): corresponding gradient, in g/cm.

References

Grissom, W., Khalighi, M., Sacolick, L., Rutt, B. & Vogel, M (2012). Small-tip-angle spokes pulse design using interleaved greedy and local optimization methods. Magnetic Resonance in Medicine, 68(5), 1553-62.