Motion correction in PET brain studies

Brain studies recorded with positron emission tomography (PET) may last between a few minutes and some hours. Head motion during long scans lead not only to blurred images, but may also seriously disturb the kinetic analysis of the metabolic information contained in the PET data. With the increase of scanner resolution this problem becomes more and more important. In the last years some methods to correct for motion have been proposed. Here we describe these approaches, especially those examined and established in our PET laboratory. We also report our first experiences regarding the accuracy of motion correction and the consequences related to the linearized calculation of metabolic images.