Motion correction is an important preprocessing step in fMRI research1. Motion artefacts not only affect image quality but can lead to erroneous results which are normally corrected using a volume registration algorithm (VRA). Here we demonstrate that when global intensity changes are present in the data (e.g., caused by a CO2 challenge during measurement of cerebrovascular reactivity (CVR) or by ASL tagging), the VRA misinterprets such intensity changes as motion. We compare the motion derived from the VRA with motion parameters derived from an external optical tracking system to determine the extent of the problem.
This abstract and the presentation materials are available to members only; a login is required.