dear John,
thanks for your suggestions. i've done what you suggested about the gray
matter segmentation mask for functionals.
now i'd like to put together results from more than 1 session and
compare the analysis from other subjects.
so i need all subjects to be in the same space and segmentation mask to
be the same for all subjects
either
1- calculate normalization parameters for my T1 structural to T1 template
2- segment Gray matter in my T1 structural
3- normalize gray matter segmentation mask to T1 template using
parameters estimated at step 1 above
4- normalize all (preprocessed=slice tim. + realign to 1 image) sessions
from each subject to T1 template
5- apply normalized segmentation mask from step 3 to normalized
functionals from step 4
otherwise I could do the following:
1- conduct analysis from not segmented functional images from all subjects
2- write my results about activations in results.img analyze image for
each session from each subject
3- normalize results.img from step 3 using parameters calculated on T1
structural
4- segment result.img using segmentation mask calculated on normalized
T1 structural
I was thinking the second way could avoid some error propagation for
voxels signal, using normalization just for representation in the same space
do you think that makes sense?
any help is welcome
danilo
John Ashburner ha scritto:
>> i'd like to obtain a gray matter segmentation binary mask for my
>> functional volumes.
>>
>> 1- I was thinking of coregistering T1 sagittal to functional mean image
>> and segment the T1. My original structural T1 images are sagittal,
>> while functionals are axial: could that be a problem?
>>
>>
>
>I would suggest using the Display button to reorient all your images to be
>axial. See the mailing list for clues about this (keywords Display and
>Reorient).
>
>
>
>> 2- Is it possible to obtain a binary mask out of Gray Matter segmented
>> T1 analyze file at the functionals resolution?
>>
>>
>
>1) Coregister the structional and functional data (reslicing not necessary).
>2) Segment the structural image.
>3) Use the Coregister button to reslice the seg1 image to match one of your
>functional images (Space defining image: functional, Images to reslice:
>seg1).
>
>Best regards,
>-John
>
>
>
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