Motion artifacts in fast spin-echo imaging.

The purpose of this work is to obtain a better understanding of motion artifacts in fast spin-echo imaging, in order to eventually identify efficient ways of suppressing them. To do so, the point spread function of a moving point was calculated for fast spin-echo imaging, and experimental data were acquired by imaging a moving liquid sphere with a diameter of 1.5 mm. The agreement of the experimental results with the calculated point spread function is shown to be excellent. It was found that motion artifacts in fast spin-echo imaging arise from the convolution of two distinct band patterns. One of these patterns may dominate the convolution, giving its own spacing to the resulting image. For other acquisition parameters, the convolution results in an intricate pattern that may appear to lack overall structure.