pulpy.sim.abrm_ptx

pulpy.sim.abrm_ptx(b1, x, g, dt, fmap=None, sens=None)[source]

N-dim RF pulse simulation

Assumes that x has inverse spatial units of g, and g has gamma*dt applied.

Assumes dimensions rf = [Nc, Nt], x = […,Ndim], g = [Ndim,Nt], and sens = [Nc, dim, dim].

Parameters:

  • b1 (array) – rf waveform input samples in radians.

  • x (array) – spatial locations (m).

  • g (array) – gradient array (mT/m with gamma*dt applied).

  • dt (float) – hardware dwell time (s).

  • fmap (array) – off-resonance map (Hz).

  • sens (array or None) – B1+ sensitivity matrix. If None, creates matrix of 1’s. Input size [Nc dim dim]

Returns:

4-element tuple containing

  • a (array): SLR alpha parameter.

  • b (array): SLR beta parameter.

  • m (array): transverse magnetization.

  • mz (array): longitudinal magnetization.

References

Pauly, J., Le Roux, Patrick., Nishimura, D., and Macovski, A.(1991). ‘Parameter Relations for the Shinnar-LeRoux Selective Excitation Pulse Design Algorithm’. IEEE Transactions on Medical Imaging, Vol 10, No 1, 53-65.

Grissom, W., Xu, D., Kerr, A., Fessler, J. and Noll, D. (2009). ‘Fast large-tip-angle multidimensional and parallel RF pulse design in MRI’ IEEE Trans Med Imaging, Vol 28, No 10, 1548-59.