Dear SPMers,
I encountered a problem during preprocessing of my fMRI data using SPM5.
One of the subjects showed large movements (up to 4cm) during the last
quarter of the experiment. Due to that, the late scans did not cover the
whole
brain anymore (temporal lobe missing; see attached picture: the top panels
show an early scan on the left, a late scan on the right.)
After realignment, the lower portion of the brain was missing in all
volumes,
whether acquired late or early during the experiments (see bottom panels
in the attached picture. left: early scan; right: late scan).
I tried both options "Register to first" and "Register to mean", but the
results
were the same.
Due to the large movements, I may not be able to use the data of this
late experimental phase anyway. However, I would like to understand,
why the lower brain portion is missing in all volumes after realignment.
I would have expected that this is only the case in the late volumes, where
it was missing from the beginning on.
Any advice would be aprreciated.
Thanks
Julia
Julia Weiler
Ruhr-University Bochum
Inst. of Cognitive Neuroscience
Department of Neuropsychology
GAFO 05/606
Phone: +49-234-3223574
Fax: +49-234-3214622
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