pulpy.rf.adiabatic.bir4

pulpy.rf.adiabatic.bir4(n, beta, kappa, theta, dw0)

Design a BIR-4 adiabatic pulse.

BIR-4 is equivalent to two BIR-1 pulses back-to-back.

Parameters:

• n (int) – number of samples (should be a multiple of 4).

• beta (float) – AM waveform parameter.

• kappa (float) – FM waveform parameter.

• theta (float) – flip angle in radians.

• dw0 – FM waveform scaling (radians/s).

Returns:

2-element tuple containing

• a (array): AM waveform.

• om (array): FM waveform (radians/s).

References

Staewen, R.S. et al. (1990). ‘3-D FLASH Imaging using a single surface coil and a new adiabatic pulse, BIR-4’. Invest. Radiology, 25:559-567.