Development of event-based motion correction techniquie for PET study using list-mode acquisition and optical motion tracking system

Since recent Positron Emission Tomography (PET) scanner has a high spatial resolution, head motion during brain PET study could cause motion artifact on the image, which might make serious problem in terms of image quality as well as image quantity. Several techniques have been proposed to correct head movement in PET images, for example SPM and AIR software packages. However these techniques are only applicable for correcting the motion between two scans and assume no head movement during scanning. The aim of this study is to develop a technique to correction head motion in event-by-event base during a PET scan using a list-mode data acquisition and optical motion tracking system (POLARIS). This system uses a rebinning procedure whereby the lines of response (LOR) are geometrically transformed according to six-dimensional motion data detected by the POLARIS. A motion-corrected Michelogram was directly composed using the reoriented LOR. In the motion corrected image, the blurring artifact due to the motion was reduced by the present technique. Since the list-mode acquisition stores data as event-by-event base, the present technique makes it possible to correct head movement during PET scanning and has a potential for real-time motion correction of head movement.