>Dear Mark,
thanks for your quick replay! I'll try to do as you suggested.
All the best,
Roberta
Dear Roberta,
>
> If your image from SPM is in MNI space (and I assume it is) then what you
> are doing is probably fine. However, it might be safer to do the
> following:
>
> flirt -in VBMimage -ref FIRSTimage -usesqform -applyxfm -out VBM_highres
>
> This will make sure that the coordinate centres are perfectly aligned in
> the MNI space, in case there are any subtle things like half-voxel shifts
> due to different coordinate conventions between SPM and FSL. It may give
> you exactly the same output as what you've already done, in which case
> they're both fine, but if there is a difference I would go with the result
> of the above flirt call, assuming that it looks correct by eye.
>
> All the best,
> Mark
>
>
> On 23 Apr 2013, at 11:13, Roberta Vasta <[log in to unmask]> wrote:
>
>> Hi all,
>> I need to superimpose VBM (SPM) to vertex analysis results in order to
>> highlight that the latter is more sensitive than the former to
>> subregional changes. I focused on hippocampus.
>> VBM results are represented by a 91x109x91 image, while the basestruct
>> built by first3Dviewer (FSL5.0) has dimension 182x218x182.
>> I tried to transform the VBM image into vertex one applying FLIRT
>> transformation:
>>
>> input volume: VBM image
>> Output size-Base on voxel dimensions- num voxel: 182x218x182 and voxel
>> size 1x1x1 (vertex image dimension)
>>
>> Then I superimposed vertex analysis image and VBM converted one by
>> fslview.
>>
>>
>> How can I be sure that the transformation was successful and that the
>> two images are centered at the same point?
>> Is there a more rigorous way to transform and then superimpose them?
>>
>> Thanks
>
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