Sounds like FAST doesn't keep the negative voxel dimension, but one
thing to consider is that you would probably be better off running FAST
on your data in their original space then registering the data to the
template afterwards. The interpolation that happens as a consequence of
registration won't help with the segmentation, and it's easy to apply
FLIRT transforms to the segmentations afterwards.
Clare E. Mackay, Ph.D.
Prince of Wales International Research Centre (POWIC),
University Department of Psychiatry,
Warneford Hospital, Oxford. OX3 7JX. UK
tel: 01865 455910 fax: 01865 455922
OCMR: 01865 221866 / 72
[log in to unmask] www.psychiatry.ox.ac.uk/powic
>>> [log in to unmask] 07/22/04 3:43 PM >>>
Sorry everyone! This should read:
"it seems as if the Talairach origin is not carried over by **Fast**
It is Fast that I am having problems with, NOT Flirt.
On 22/7/04 3:17 pm, "Dr Krish Singh" <[log in to unmask]> wrote:
> Just to add to my last post, it seems as if the Talairach origin is
> carried over by Flirt either.
>> Hi there,
>> I've got myself into some laterality difficulties with negative voxel
>> dimensions. Let me explain what I did:
>> 1) Using flirt I registered a radiological axial volume to the FSL T1
>> avwhd now reports that this has voxel dimensions of -2,2,2 mm which
>> I think.
>> 2) I took the registered volume generated in the above step and
>> through Flirt to generate segmentation maps. avwhd now reports that
>> dimensions for the segmented images are 2,2,2 which I don't think is
>> they should be the same as the input image.
>> Is the above behaviour expected? It causes me some problems because
>> software, mri3dX, assumes that if you overlay one volume on another
>> horizontal voxel dimensions have different signs, then it needs to
>> laterality of the overlay. In the case of the above, this is clearly
>> All the best,
> Dr K.D. Singh
> Senior Lecturer and Convenor of the Neuroimaging Research Group,
> Director, MRI Research Centre,
> Neurosciences Research Institute
> Aston University, Birmingham B4 7ET, U.K.
> Tel/Fax: +44 (0)121 [204 3865/3864]/[333 4220]
> [log in to unmask], http://www.aston.ac.uk/lhs/staff/singhkd/
Dr K.D. Singh
Senior Lecturer and Convenor of the Neuroimaging Research Group,
Director, MRI Research Centre,
Neurosciences Research Institute
Aston University, Birmingham B4 7ET, U.K.
Tel/Fax: +44 (0)121 [204 3865/3864]/[333 4220]
[log in to unmask], http://www.aston.ac.uk/lhs/staff/singhkd/