Medical Biometrics.

Abstract

The problem of motion in PET/CT studies results from the fact that the PET images are formed over an elongated period of time whereas the CT acquisition takes only a few seconds. Additionally, the CT images are also used for attenuation correction of the PET data. The spatial discrepancy between the two sets of images, however, may lead to wrong attenuation and thus to wrong quantification of the radioactive uptake. We present a solution to this problem by respiratory-gating the PET data and correcting the PET images for motion with a multiresolution optical flow algorithm. Our algorithm is based on the combined local and global optical flow algorithm with modifications to allow for discontinuity preservation across organ boundaries and for application to 3D volume sets. © Springer-Verlag Berlin Heidelberg 2007.