(DANTE) A technique used to place a saturation band over e.g. the myocardium. This technique includes spatial modulation of magnetization complementary and delays alternating with nutations for tailored excitation, followed by the application of a cine or real-time imaging. Because the saturated magnetization pattern moves with the atoms of the tissue, the cardiac motion shows up as deformations in the grid pattern in the resulting imaging sequence.

(FAIR) In this sequence 2 inversion recovery images are acquired, one with a nonselective and the other with a slice selective inversion pulse. The z-magnetization in the first sequence is independent of flow. Inflowing spins give z-magnetization from second pulse. A major signal loss in FAIR is the T1 relaxation of tagged blood in transit to the imaging slice. Sharper edges of the inversion pulse give narrow spacing between the inversion edge and the 1st slice because reduced transit time gives lower T1 relaxation induced signal loss. The difference of the images in a consequence contains information proportional to flow (blood partition coefficient). Standard adiabatic inversion RF pulse does not have good slice-profile, because of power/SAR limitation. A c-shaped frequency offset corrected inversion (FOCI) RF pulse can help to increase the signal.
Perfusion imaging, e.g. myocardial, using tissue water as endogenous contrast is suggested.

(FID) A free induction decay curve is generated as excited nuclei relax. The amplitude of the FID signal becomes smaller over time as net magnetization returns to equilibrium. If transverse magnetization of the spins is produced, e.g. by a 90° pulse, a transient MR signal will result that will decay toward zero with a characteristic time constant T2 (or T2*); this decaying signal is the free induction decay.
The signal peaks of the echoes fall onto this T2 decay curve, while at each echo the signals arise and decay with T2*. The typical T2 relaxation times being of the order of 5-200 ms in the human body. The first part of the FID is not observable (named the 'receiver dead time') caused by residual effects of the powerful exciting radio frequency pulse on the electronics of the receiver.

(GMR) The application of strategic gradient pulses can compensate the objectionable spin phase effects of flow motion. That means the reducing of flow effects, e.g. gradient moment nulling of the first order of flow. The simplest velocity-compensated pulse sequence is the symmetrical second echo of a spin echo pulse sequence.
Gradient field changes can be configured in such a way that during an echo the magnetization signal vectors for all pixels have zero phase angle independent of velocities, accelerations etc. of the measured tissue. E.g. the adjustment to zero at the time TE of the net moments of the amplitude of the waveform of the magnetic field gradients with time. The zeroth moment is the area under the curve, the first moment is the 'center of gravity' etc. The aim is to minimize the phase shifts acquired by the transverse magnetization of excited nuclei moving along the gradients (including the effect of refocusing RF pulses), particularly for the reduction of image artifacts due to motion.
Also called Flow Compensation (FC), Motion Artifact Suppression Technique (MAST), Flow motion compression (STILL), Gradient Rephasing (GR), Shimadzu Motion Artifact Reduction Technique (SMART).

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.