sigpy.mri.spiral

sigpy.mri.spiral(fov, N, f_sampling, R, ninterleaves, alpha, gm, sm, gamma=267800000.0)[source]

Generate variable density spiral trajectory.

Parameters:
  • fov (float) – field of view in meters.
  • N (int) – effective matrix shape.
  • f_sampling (float) – undersampling factor in freq encoding direction.
  • R (float) – undersampling factor.
  • ninterleaves (int) – number of spiral interleaves
  • alpha (float) – variable density factor
  • gm (float) – maximum gradient amplitude (T/m)
  • sm (float) – maximum slew rate (T/m/s)
  • gamma (float) – gyromagnetic ratio in rad/T/s
Returns:

spiral coordinates.
Return type:

array

References

Dong-hyun Kim, Elfar Adalsteinsson, and Daniel M. Spielman. ‘Simple Analytic Variable Density Spiral Design.’ MRM 2003.