Hi Mark,
Thanks a lot for the message, :)
You know, I'm not doing image registration on different subjects. I have the
same subject whose T2-weighted images and b0 images were done on the
same day, and I tried two different ways to register the two image volumes. I
just want to get some values to quantify the registration and see if there's a
pattern. Could you suggest some ready-to-use script? Will fslmaths work?
Thanks a lot,
Jim
On Tue, 29 Sep 2009 08:17:52 +0100, Mark Jenkinson
<[log in to unmask]> wrote:
>Hi,
>
>I'm afraid that there is no easy way to compare the quality of
>registrations for different subjects. You can use mutual information
>or other metrics to compare the quality of two different registrations
>of the same images (this is how the registration works), but the values
>are not really comparable across different registrations of different
>images/subjects, and will tend to be influenced a lot by the FOV,
>SNR, artefact level (e.g. amount of motion) and so on. Hence a
>larger/smaller number does not necessarily indicate a change in
>the quality of the alignment.
>
>We strongly recommend you visually inspect all your registrations.
>This is definitely the best way to assess the quality of the alignment.
>
>All the best,
> Mark
>
>
>On 28 Sep 2009, at 14:46, Jim Li wrote:
>
>> Hello everybody,
>>
>> I have another Newbie question about registering two image volumes
>> of the
>> same subject using the same modality (MRI) after using FLIRT or
>> other scripts.
>> Can anyone give me a hint?
>>
>> Basicly, other than visual inspection of the two images after
>> registration, are
>> there ready-to-use scripts in FSL that can quantify the overall
>> goodness of
>> registration? I heard people use mutual information, etc. I just
>> want to run a
>> command to get a number (or more) to quantify the goodness of
>> registration...
>>
>> Thanks a lot, :)
>>
>> Jim
>>
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