Hi Doug and Martin,
Thanks both for your responses. I am working with PK11195, AV-1451, and PiB. In general, the standard bbregister routine with init-fsl works well for AV-1451 (adjustments needed in 30% of cases) and PiB (best performance), but it completely failed with the PK data which was acquired on the same scanner. I tried running the registration using the mean image (mri_concat --mean) but it did not help too.
All that being said, mri_coreg works extremely well for the PK11195 (only 3 manual adjustments needed so far for > 50 scans), so I am very grateful for this tool :)
If I want to run the analyses of the various PET data in the same study, will it be of concern that I am using a mix of boundary-based (AV and PIB) and normalised mutual information (PK)?
Best Wishes, Elijah
Re: [Freesurfer] mri_coreg ! http://www.mail-archive.com/search?l=freesurfer@nmr.mgh.harvard.edu&q=subject:%22Re%5C%3A+%5C%5BFreesurfer%5C%5D+mri_coreg+%5C%21%22&o=newest
Martin Reuter http://www.mail-archive.com/search?l=freesurfer@nmr.mgh.harvard.edu&q=from:%22Martin+Reuter%22 Mon, 16 May 2016 13:23:13 -0700 http://www.mail-archive.com/search?l=freesurfer@nmr.mgh.harvard.edu&q=date:20160516
Hi,
just wanted to mention that the --cost NMI (normalized mutual information) and MI implementations in mri_robust_register are the same as spm_coreg and now mri_coreg (if the -nosym flag is specified in robust register, else it is registering in a symmetric midspace instead into the target space). If you have cases where robust_register fails, but the other tools work, let me know, because that could indicate a bug in my code.
Thanks, Martin
On 05/16/2016 03:19 PM, Douglas N Greve wrote:
It is my implementation of the spm_coreg program written by John Ashburner using normalized mutual information. I liked the spm program so much that I put the effort into replicating its behavior in C. My guess is that BBR was failing because the initialization was failing. Still I like mri_coreg for PET data because the blurriness can throw BBR off a bit. What kind of PET data do you have?
On 05/16/2016 03:06 PM, Elijah Mak wrote:
Hi Doug,
I just want to say that mri_coreg worked tremendously well for the registration of some very blurry PET-PK data. I was not getting any success with bbregister and init-fsl or mri_robust_register options.
How does this technique differ from the boundary-based registration?
Thanks a lot.
Best Wishes, Elijah
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