MOTION ARTIFACT COMPENSATION

A technique for correcting translational and rotational motion of an object, such as an object in a magnetic field, utilizes the k-space representation of the object. An initial region in the k-space representation is used as a motion-free reference region, indicative of the motion-free object. Motion-free data adjacent to the initial region are then estimated by extrapolating from the initial region, and the extrapolated data are subsequently used to estimate motion by correlating it with actual data. Segments adjacent to the initial region are then motion corrected and incorporated into an expanding base region. The expanded base region is used in subsequent correction steps. This process is continued until the entire k-space is motion-corrected. Two different extrapolation methods were used for the purpose of motion estimation: edge enhancement and finite-support solution. One technique is utilized near the k-space center and the other is utilized in the outer k-space regions.