On 11/27/06, Steve Smith <steve@fmrib.ox.ac.uk> wrote:

Indeed - you don't just want to do pairwise subtraction Abi, it's
better to do sub-TR timing-adjustment on the tagged and control data
before subtraction - if you look in the latest version of FEAT in FSL
you'll see options for easy preprocessing of ASL data. You would then
be able to use the normal methods for transferring FEAT data into
FreeSurferSpace.

Cheers, Steve.

On 27 Nov 2006, at 17:47, Doug Greve wrote:

>
> We don't have an MC program. You can try running FSL's FLIRT or AFNI's
> 3dvolreg. As for analysis, you should be able run
>
> mri_concat --paired-diff --mean inputaslvolume outputvolume
>
> I've never actually tried it like this, but it should work.
>
> doug
>
>
> On Mon, 27 Nov 2006, Abi Gopal wrote:
>
>> Hi all
>>
>> I have collected some raw Arterial Spin Labeling (ASL) data.  I
>> would like
>> to use freesurfer to create perfusion maps of this data.  Is it
>> possible to
>> take the raw data, motion correct it, perform a pairwise
>> subtraction, and
>> then average all the subtractions to create a mean perfusion map?
>> Please
>> let me know if you have ideas on how to do this sort of thing.
>>
>> Thanks
>> Abi
>>
>>
>
> --
> Douglas N. Greve, Ph.D.
> MGH-NMR Center
> greve@nmr.mgh.harvard.edu
> Phone Number: 617-724-2358 Fax: 617-726-7422
>
> In order to help us help you, please follow the steps in:
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>
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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)
steve@fmrib.ox.ac.uk    http://www.fmrib.ox.ac.uk/~steve
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