Thanks Martin and Doug,
I'll give both robust_register with robent and mri_coreg a try.
RE: Doug The PET tracer is Avid's amyloid compound -- F18-florbetapir (aka amyvid, aka AV45). The asymmetric signal is a result of the population -- individuals with a non-amnestic language dementia with underlying Alzheimer's pathology. I realize the focal left lateralized atrophy could play a role in partial voluming, next step is PVC.
Thanks again, Adam
On Thu, Mar 31, 2016 at 12:13 PM, Douglas N Greve <greve@nmr.mgh.harvard.edu
wrote:
btw, what tracer is this? And the asymmetry you are talking about is between the hemispheres? Is that typical for this tracer or is this a phenomena with this subject (or population)?
On 03/30/2016 03:41 PM, Adam Martersteck wrote:
Hi Freesurfer team,
I’m encountering a problem using bbregister on PET data:
-- When I attempt to register a PET volume to T1-space the asymmetric tracer uptake of the PET throws off proper registration. (Treating the PET as a T1 because of the non-specific white matter uptake > grey matter signal).
-- You can really see the bbregister mis-registration in this gif here: https://goo.gl/iM6yrT
-- It (expectedly) attempts to find the best match between signal intensities on both the left and right surfaces, but is inherently biased by the asymmetric uptake shifts the entire volume to the right.
-- Are there any suggestions for dealing with asymmetric scans like this? Stick with just a simple FLIRT? It doesn't seem to do that great a job for everyone.
Cutting left and right hemispheres apart and register separately?
Using Martin’s new robust register for multi-modal data? Any suggestions on the parameters of ROBENT?
Thanks, Adam
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
-- Douglas N. Greve, Ph.D. MGH-NMR Center greve@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422
Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.