sigpy.mri.rf.adiabatic.bloch_siegert_fm

sigpy.mri.rf.adiabatic.bloch_siegert_fm(n=512, dur=0.002, b1p=20.0, k=42.0, gamma=267.53803037970675)[source]

U-shaped FM waveform for adiabatic Bloch-Siegert \(B_1^{+}\) mapping and spatial encoding.

Parameters:
  • n (int) – number of time points
  • dur (float) – duration in seconds
  • b1p (float) – nominal amplitude of constant AM waveform
  • k (float) – design parameter that affects max in-band perturbation
  • gamma (float) – gyromagnetic ratio
Returns:

FM waveform (radians/s).
Return type:

om (array)

References

M. M. Khalighi, B. K. Rutt, and A. B. Kerr. Adiabatic RF pulse design for Bloch-Siegert B1+ mapping. Magn Reson Med, 70(3):829–835, 2013.

M. Jankiewicz, J. C. Gore, and W. A. Grissom. Improved encoding pulses for Bloch-Siegert B1+ mapping. J Magn Reson, 226:79–87, 2013.