Freddy Odille1, Philip G. Batchelor2, Claudia Prieto2, Tobias Schaeffter2, David Atkinson1
1Centre for Medical Image Computing, University College London, London, United Kingdom; 2Division of Imaging Sciences, King's College London, London, United Kingdom
Generalized reconstruction algorithms have been proposed in order to correct for artifacts induced by nonrigid motion. However they are very time-consuming because large scale inverse problems have to be solved. Here we propose a technique for splitting the reconstruction into several smaller problems, based on the properties of the point-spread function associated with motion artifacts, which uses the local nature of artifacts (blurring) in the frequency-encoding direction. The method was implemented on a cluster of workstations, and applied to the correction of real motion-corrupted data. Efficient motion correction was achieved, with reconstruction times reduced by an order of magnitude.