Hi - if you slices have a gap then that gap needs to be added onto
the true slice thickness when creating the voxel dimension entries in
the header. This will be true for any further analysis.
Also, you may want to use FDT (in particular eddy_correct and dtifit)
instead of the Siemens software if the latter does not correct for
eddies and head motion.
Once the above is all sorted hopefully TBSS will work ok - though
note that you probably shouldn't combine axial and sagittal data in
the same analysis.
Cheers.
On 11 Jul 2007, at 14:29, Thomas Doering wrote:
> Hello,
> i tried to make a simple 2 group comparison with TBSS on the FA
> maps-produced direct on the scanner with Siemens Software (instead
> of using FDT). I have one data set of axial FA maps (from axial DTI
> sequence) and another data set of sagital FA maps (from the
> sagital sequence).
> When i run tbss on just the axial FA data set, the registration
> into the MNI152 space is not working well, because there is a gap
> between the slices, so missing information. The same i expect in
> the sagital FA data set.
> My question is how i can use my two data sets in the best way? Is
> there a way to joint the axial and sagital data?
> When i would use FDT, i could adress that problem?
>
> Thanks for any help!
> Thomas
>
>
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Stephen M. Smith, Professor of Biomedical Engineering
Associate Director, Oxford University FMRIB Centre
FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
+44 (0) 1865 222726 (fax 222717)
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
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