Hello everyone
From FSL, I derived the HarvardOxford probability images in FSL’s own taste of MNI space (MNI152NLin6Asym). I would like to have those in MNI152NLin2009cAsym space (not the maxprob image: I want a 4D image with one 3D image for every brain area included in the atlases, where the respective 3D images gives me the probability of a voxel being in this brain area).
As pointed out in this discussion before, templateflow archive nicely provides an ITK transform to map information from MNI152NLin6Asym space onto MNI152NLin2009cAsym. I applied this transform on the HarvardOxford-images from FSL using ants and got what I wanted, it looks nice on the first glance
(As a reference, I used the NLin2009cAsym-T1w-image provided by templateflow. Interpolation set to linear)
Now, just to see if everything checks out, I thresholded those pictures at 0, 25 and 50 and derived the maxprob-images. Then I compared those to the maxprob-images provided by templateflow. They are like 95% the same and therefore I assume I didn’t make a huge mistake like wrongly thresholding or applying the wrong transform or something like that. But at the edges of several brain areas, there are some differences between the two.
So since I am rather new to MRI imaging, I have to ask: Two maxprob-images of the same atlas in the same space differ in their information - is that, like, ok or normal? Would one expect differences there? Does anyone know where these differences could come from?
And most importantly: Is the transformed probability image still usable on fMRI data that is in MNI152NLin2009cAsym space?
Thanks a lot for every helpful answer