In-room imaging and MR planning

Motion Artifacts

While noise has a stochastic nature, artifacts arises for specific reasons, and sometimes can be corrected or reduced.

All artifacts are due to some inconsistencies in the projections. For example motion artifacts are generated when an object moves during the acquisition. Since the object is moving, only some projections are passing through it, while other that should have intersected the object do not intersect it anymore, and the other way around.

Some of the possible ways to solve this issue are: - Improving scan speed - Instructing the patient - Acquiring data with less than 180° of rotation. This would generate other types of artifacts (namely truncation artifacts) since the data are incomplete, but these new artifacts might be easier to correct for. - Reduce entropy in selected regions of the image