sigpy.mri.rf.trajgrad.rosette

sigpy.mri.rf.trajgrad.rosette(kmax, w1, w2, dt, dur, gamp=None, gslew=None)

Basic rosette trajectory designer.

Parameters:

• kmax (float) – 1/m.
• w1 (float) – rotational frequency (Hz).
• w2 (float) – center sampling frequency (Hz).
• dt (float) – sample time (s).
• dur (float) – total duration (s).
• gamp (float) – max gradient amplitude (mT/m).
• gslew (float) – max slew rate (mT/m/ms).

Returns:

(g, k, t, s) tuple containing

• g - (array): gradient waveform [mT/m]
• k - (array): exact k-space corresponding to gradient g.
• time - (array): sampled time
• s - (array): slew rate [mT/m/ms]

Return type:

tuple

References

D. C. Noll, ‘Multi-shot rosette trajectories for spectrally selective MR imaging.’ IEEE Trans. Med Imaging 16, 372-377 (1997).