You could always apply the transformation matrix of FA to anatomical to the
MD to get the MD in anatomical space.
Peace,
Matt.
-----Original Message-----
From: FSL - FMRIB's Software Library [mailto:[log in to unmask]] On Behalf
Of Hedok Lee
Sent: Thursday, October 09, 2008 7:42 AM
To: [log in to unmask]
Subject: Re: [FSL] normalize non-FA image in TBSS
Hi Steve,
The reason for having different header information is that I
coregistered FA image with anatomical while MD image was kept
unprocessed. I assume it's ok to apply normalization parameters as long
as two images have the same "space" as in same voxel counts. Both images
are acquired from the same run.
"FA"
dim0 3
dim1 256
dim2 256
dim3 26
dim4 1
dim5 1
dim6 1
dim7 1
"MD"
dim0 3
dim1 256
dim2 256
dim3 26
dim4 1
dim5 1
dim6 1
dim7 1
Hedok
Steve Smith wrote:
> Hi - if the raw data is in the same space in FA and MD images then
> this should be fine - however, I would be concerned possibly about why
> they have different headers though - dtifit should have given all its
> outputs the same headers, spatially....
>
> Cheers.
>
>
> On 9 Oct 2008, at 04:08, Hedok Lee wrote:
>
>> Dear FSLers:
>>
>> I have a question regarding TBSS normalization of non-FA images. My
>> apologies if it has been answered already.
>>
>> I'm using FSL 4.1 (TBSS with FNIRT).
>>
>> Question:
>> Is it necessary for non-FA to have the same voxel-to-world mapping as
>> the FA
>> if I were to analyze the non-FA image using the normalization parameters
>> derived from FA?
>>
>> For example, a FA image has a nifiti header of
>>
>> qto_xyz:1 -1.014429 -0.047513 0.069794 133.319595
>> qto_xyz:2 -0.048589 1.010437 -0.444181 -129.897827
>> qto_xyz:3 0.009884 0.090794 4.979743 -71.412193
>> qto_xyz:4 0.000000 0.000000 0.000000 1.000000
>>
>> But non-FA image (MD) has
>> qto_xyz:1 -1.015640 0.000000 -0.000000 129.492004
>> qto_xyz:2 0.000000 1.005132 -0.716720 -128.102585
>> qto_xyz:3 0.000000 0.145583 4.948366 -78.129471
>> qto_xyz:4 0.000000 0.000000 0.000000 1.000000
>>
>> I also appreciate if there is a simple way to copy header information
>> from
>> FA to non-FA.
>>
>> Thanks,
>>
>> Hedok
>>
>
>
>
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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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