Abstract #2345

Waites A, Mannfolk P, Nilsson A, Olsrud J

In BOLD fMRI activation/blood flow is detected through small induced changes of the local magnetic field. Other factors that influence the magnetic field, such as motion, can easily affect the results. In this study we investigate the influence on GRE-EPI signal when an external object (hand) is extended into the tunnel. It is shown that temporally well correlated signal changes are iduced with a magnitude quite comparable to those normally found in activated areas during an fMRI study