Dear Mark
Thank you very much for your e-mail
In fact the DaTScans are very different to "normal" SPECT or PET, e.g. FDG PET. In the latter you have activity in the entire brain, so I think that normalization to a T1 (maybe after BET) should be possible (although I have no personal experience here).
The image of a DaTScan is fundamentally different (see attachment). In fact activity is present only in the basal ganglia. I think that therefore the procedure to normalize the scans should be very different.
I like FSL, and I would like to analyze VBM and TBSS. Therefore it would be best to analyze the DaTScan also in FSL, followed by a RANDOMISE analysis
Any help is highly appreciated
Sven
PS: The image was refused (too large). Maybe I can send it to you in another way??
On 16 mars 2011, at 09:29, Mark Jenkinson wrote:
> Dear Sven,
>
> I have no direct experience of DATSCANs but I assume they are similar
> to general SPECT or PET scans. We have had success registering
> SPECT/PET to MRI before. It is always better to register the SPECT/PET
> to that subject's MRI using 6 DOF with FLIRT and a cost function like
> mutualinfo or normmi. I would normally choose the best T1-weighted
> scan as the reference, but it may depend on what features are most
> clearly seen in your DATSCAN.
>
> Once you've got a good registration of your DATSCAN to your MRI,
> then you can register the MRI to the MNI standard space image.
> This registration can be done with non-linear (FLIRT then FNIRT)
> whereas it is usually very, very bad to try and register the SPECT/PET
> with non-linear directly as there are very few features there to drive
> that registration.
>
> When you have the two registrations then you can combine them with
> convertwarp to get a non-linear registration from the DATSCAN to
> the MNI standard space.
>
> I do not know what you want in terms of a "specific template of the
> basal ganglia" but we have several atlases in FSL, and they include
> basal ganglia parcellations.
>
> All the best,
> Mark
>
>
>
> On 16 Mar 2011, at 07:37, Sven Haller wrote:
>
>> Dear all
>>
>> I would like to normalize DATSCANs to MNI standard space
>> I also have 3DT1 (easy using FSLVBM) and DTI (easy using TBSS).
>>
>> Are there any existing tools for FSL for DATSCANs?
>> Is there a specific template of the basal ganglia?
>> Any experience whether it is better to perform a linear registration DATSCAN to DTI, and then use the non-linear registration of TBSS, or better directly register DATSCAN to NMI? In that case, how? Linear or non-linear?
>>
>> Any help is highly appreciated
>>
>> Sven
>>
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