(M2DMRA) The M2D technique can be used to image both fast and slow flow, due to good refreshment of flowing blood. Using overlapping slices can reduce staircase artifacts, which might be seen in projection of the slice thickness.

See also Time of Flight Angiography.

Partial averaging is a scan time reduction method that takes advantage of the complex conjugate of the k-space. The number of phase encoding steps of the acquisition matrix are reduced in the phase encoding direction.
Since negative values of phase encoded measurements are identical to corresponding positive values, only a little over half (more than 62.5%) of a scan actually needs to be acquired to replicate an entire scan. This results in a reduction in scan time at the expense of signal to noise ratio. The time reduction can be nearly a factor of two, but full resolution is maintained.
Partial Fourier averaging can be used when scan times are long, the signal to noise ratio is not critical and where full spatial resolution is required. Partial averaging is particularly appropriate for scans with a large field of view and relatively thick slices; and in 3D scans with many slices. In some fast scanning techniques the use of partial averaging enables a shorter TE thus improving contrast.
Partial averaging is also called Fractional NEX, Half Scan, Half Fourier, Phase Conjugate Symmetry, Single Side Encoding.

Quick Overview

The Partial Volume Artifact is caused by imaging voxel containing two different tissues and therefore possessing a signal average of both tissues.

Take thinner slices (smaller voxel), but this may result in poorer signal to noise ratio in the image.

See Partial Volume Effect.

The partial volume effect is the loss of contrast between two adjacent tissues in an image caused by insufficient resolution so that more than one tissue type occupies the same voxel (or pixel). That may induce a partial volume artifact, dependent on the size of the image voxel. If fat and water spins occupy the same voxel, their signals interfere destructively. A small amount of water signal may be eliminated by a larger lipid signal from the same voxel, resulting in a voxel that appears to contain only lipid. The partial volume effect is minimal with thin slice thickness and sufficiently high resolution, so that fat and water or other different structures are unlikely to occupy the same voxel.

Take thinner slices, and higher resolution (smaller voxel), but remain this may result in poorer signal to noise ratio in the image.

(REST - regional saturation technique / SAT - saturation/ Pre-Sat / spatial Pre-Sat) A specialized technique employing repeated RF excitation of structures adjacent to the ROI for the purpose of reducing or eliminating their phase effect artifacts. This presaturation can be performed on both sides parallel or perpendicular to the slice. Vascular ghosting is eliminated by saturation areas parallel (outside) to the slice plane, because flowing blood produces almost no signal. The possibility of moving presaturation (moving REST / traveling SAT) makes sequence planning and scanning comfortable.