Constructive interference in [[steady-state]]

FIESTA-C is a modification of the basic [[FIESTA]]/TrueFISP sequence. The equivalent Siemens product is called CISS (Constructive Interference Steady State). FIESTA-C/CISS is composed of a pair of TrueFISP acquisitions run back-to-back preceded by an automatic shimming procedure. The first uses phase alternation of the RF-pulses (+α, −α, +α, −α, ...) while the second does not (+α, +α, +α, etc). 

see [[3D FIESTA magnetic resonance imaging]]