 |
 |
When I see the observed artifact, it also appears in the Statistic Image and the ResMS image. The likely culprit for this is subject movement and its particular evident when you have interleaved slices. Thus, I would look at a movie and also look at the motion plots. In the movie, you'll probably see a few volumes that have the striping effect and then the brain will become homogenous again. Best Regards, Donald McLaren, PhD On Wed, Aug 5, 2015 at 9:28 AM, H. Nebl <[log in to unmask]> wrote: > Dear Irina, > > A distorted beta image is rather difficult to explain as in principle, a > single volume with a certain artefact might be sufficient to affect the > beta estimate if it coincedes with the predicted time course of that > regressor. > > I'd suggest to look at the raw data. Some scanner / coil artefacts might > show up in particular slices only, if you realign & normalise data this > might not be obvious any more. E.g. sometimes, the first few volumes will > show stripes with some slices having a higher intensity than others. > ArtRepair > http://cibsr.stanford.edu/tools/human-brain-project/artrepair-software.html > might be a good try, as it has a movie function displaying all the slices > of a volume at the same time, plus there are options to increase and > color-code the contrast. > > Best > > Helmut >