Correction of periodic motion artifacts along the slice selection axis in MRI.

The effect of periodic motion of a single magnetic resonance imaging (MRI) slice in the direction of the slice selection axis is modeled as amplitude modulation of the raw data with a motion kernel along the phase encoding direction in the Fourier domain. It is shown that this motion can be detected in 1-D projections of the raw data along the frequency encoding direction which in combination with appropriate filtering leads to the recovery of the motion kernel. It is demonstrated by means of simulation examples that significant reduction in the amplitude of ghost artifacts is obtained when the image is filtered by the inverse of the motion kernel. Some issues to be investigated before the technique can be used in a clinical environment are mentioned.