sigpy.mri.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.

  • 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.

2-element tuple containing

  • pulses (array): RF waveform out.
  • g (array): corresponding gradient, in g/cm.


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.