sigpy.mri.rf.ptx.stspk¶
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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.
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.