The files are here:
- GG-FLAIR-462: This was built with images from 462 subjects, mean age:
48.2y, std dev: 13.2y, range: 26-85y, 286 females.
- GG-FLAIR-181: This was built with a subset of 181 of the above
subjects. Only those with no or very few hyperintensities were selected.
Mean age: 39.9y, std dev: 9.3y, range: 26-76y, 102 females.
Both are available in symmetrical and asymmetrical versions (the
symmetrical is just the asymmetrical averaged with a mirrored copy of
These templates were constructed by first coregistering each subject's
FLAIR to their corresponding T1-weighted image, then the T1 was warped
to the MNI space using SPM5's unified segmentation, then the warps were
applied to the (bias-corrected) FLAIR and sampled with resolution of
1mm. Some global intensity scaling was applied to ensure that all
subjects were in the same intensity range. The process is described in
The images used for these templates are not all independent
observations, as the subjects are members of families. Any feature
observed on these images are specific for the population that they have
been drawn from and not necessarily apply to other subjects or populations.
Also, notice that we don't use these FLAIR templates as targets for
registration, but the T1-weighted instead. FLAIR is sensitive to white
matter lesions and if you have hyperintensities in the brains of your
subjects, they have potential to compromise the registration. Inspect
all images to make sure the result of the normalisation is acceptable.
Hope this helps!
All the best,
On 13/01/12 01:47, John Smith wrote:
> Thank you for your reply.
> I do not have T1 images. Are your FLAIR templates in MNI space?