The chemical shift artifact of a particular material is always in one direction relative to the field and with the same magnitude.
The purpose of this study was to examine the anticipated chemical shift artifact and shape distortion of common prosthetic materials and their effect on MRI images.
The measured chemical shift artifact from casting materials could jeopardize residual limb boundary detection when constructing the 3-D model; the image of the casting material could superimpose onto the image of underlying soft tissue.
We investigated the repeatability of MRI, the chemical shift artifact, and image distortion of seven different commonly used prosthetic materials in MRI images.
5T to 3T imaging, a doubling of bandwidth is required to fully accommodate the doubled chemical shift artifact and results in a 29% decrease in SNR.
Chemical shift artifacts of the second kind are also known as "India ink" or phase cancellation artifacts and relate to the cancellation of signal in voxels containing both water and fat protons at TEs where fat and water protons are out-of-phase relative to each other.
Chemical shift artifacts, as well as magnetic and RF field inhomogeneities, are also important considerations at 3T.
An increase in chemical shift artifact
at 3T could be a significant limiting factor in routine anatomic imaging.
Jinkins continued, "Mid-field MRI may be the optimal field strength for evaluation of degenerative disease of the spine because: Magnetic susceptibility artifact (directly related to field strength) is much reduced, Chemical shift artifact
(also directly related to field strength) is much reduced, and Motion artifact is routinely much less than that experienced when using high-field units.
The Stand-Up(TM) MRI demonstrated a low claustrophobic potential and yielded relatively high-resolution images with little motion, magnetic susceptibility, or chemical shift artifacts
This is because there are less motion and chemical shift artifacts
on the images acquired at 0.