The incoherent gradient echo (gradient spoiled) type of sequence uses a continuous shifting of the RF pulse to spoil the remaining transverse magnetization. The transverse magnetization is destroyed by a magnetic field gradient. This results in a T1 weighted image. Spoiling can be accomplished by RF or a gradient.
Gradient spoiling occurs after each echo by using strong gradients in the slice-select direction after the frequency encoding and before the next RF pulse. Because spins in different locations in the magnet thereby experience a variety of magnetic field strengths, they will precess at differing frequencies; as a consequence they will quickly become dephased. Magnetic field gradients are not very efficient at spoiling the transverse steady state. To be effective, the spins must be forced to precess far enough to become phased randomly with respect to the RF excitation pulse. In clinical MRI machines, the field gradients are set up in such a way that they increase and decrease relative to the center of the magnet; the magnetic field at the magnet 'isocenter' does not change.
The T1 weighting increases with the flip angle and the T2* weighting increases with echo time (TE). Typical repetition time (TR) are 30-500 ms and TE less than 15 ms.

See also Ernst Angle.

(GRASS) This sequence is very similar to FLASH, except that the spoiler pulse is eliminated. As a result, any transverse magnetization still present at the time of the next RF pulse is incorporated into the steady state. GRASS uses a RF pulse that alternates in sign. Because there is still some remaining transverse magnetization at the time of the RF pulse, a RF pulse of a degree flips the spins less than a degree from the longitudinal axis. With small flip angles, very little longitudinal magnetization is lost and the image contrast becomes almost independent of T1. Using a very short TE eliminates T2* effects, so that the images become proton density weighted. As the flip angle is increased, the contrast becomes increasingly dependent on T1 and T2*. It is in the domain of large flip angles and short TR that GRASS exhibits vastly different contrast to FLASH type sequences.

(E-SHORT) A gradient echo sequence in which a non-zero steady state develops for transverse and longitudinal magnetization. The TR is shorter than the T1 and T2 times of the tissue.
See Gradient Echo Sequence and Steady State Free Precession.

(TurboGRASS) This GRASS-based sequence use an inversion pulse followed by a low flip angle and short TR gradient echo train.

See also Ultrafast Gradient Echo Sequence and Gradient Recalled Acquisition in Steady State.

(SARGE) Spoiled GRE sequences use a spoiler gradient on the slice select axis to destroy any remaining transverse magnetization after the readout gradient, with the result of short repetition times. This type of sequences use semi-random changes in the phase of RF pulses to produce a spatially independent phase shift.

See also Gradient Echo Sequence.