Dear SPM list,
Please excuse this mail, but I would get some advices regarding
questions on the preprocessing steps to follow for an ongoing fMRI
study.
In order to limit susceptibility artifacts on the orbito and temporal
cortices, we acquired our participants using dual Gradient/Spin echo
sequences. To you, are there some important preprocessing steps needed
by this modality ?
For now, following a classical preprocessing approach, I performed the
following steps in my data:
Realignment of the three sessions for each subject (writing the
rImages and the mean EPI of the three sessions);
Coregistration of each subject's anatomical 3D as an object to the
corresponding mean EPI as a target (reslicing the anatomical volumes);
Normalization of each anatomical on the T1 template and use of the
normalization parameters of each anatomical volume to writte
normalized functional volumes.
When looking after head motion correction, the functional and
anatomical volumes of each subject are not in correspondence (the
cross hair does not indicate the same structure when doing a check reg
of functional volumes pertaining to different participants).
After normalization, the correspondence looks perfect.
May I assume that the normalization corrected the correspondence
between subjects or should I plan an inter-subjects coregistration
stows befogging launching the normalization ?
Any advice would be greatly appreciated,
Thank you very much in advance.
Sincerely yours,
Harold Mouras
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