Hello, I am wondering whether there is any way to compensate for motion in anatomical images (for the purposes of salvaging data for cortical thickness analysis)? If not, is there a general rule of thumb or some way to tell how much motion is too much for this type of analysis? Or is it more of a matter of reconstructing the images and seeing whether the surfaces look good?
Thanks!
Cindy Krafft
Hi Cynthia
motion in 3D anatomical scans doesn't work the same way as in 2D functional scans since the data is being acquired in spatial frequency ("k-space"), not in space. There are sequences around that compensate for motion, including one recently developed at MGH by M Dylan Tisdall and Andre van der Kouwe, but you probably are not using a motion-compensated sequence so there's not much to do to correct it. You could look at the noise in the background to try to compute amount of motion, but typically we just visualize them
cheers Bruce
On Thu, 17 Nov 2011, Cynthia Elisabeth Krafft wrote:
Hello, I am wondering whether there is any way to compensate for motion in anatomical images (for the purposes of salvaging data for cortical thickness analysis)? If not, is there a general rule of thumb or some way to tell how much motion is too much for this type of analysis? Or is it more of a matter of reconstructing the images and seeing whether the surfaces look good?
Thanks!
Cindy Krafft
freesurfer@nmr.mgh.harvard.edu