Dear Freesurfers,
We are running a longitudinal study with 4 time points. The first two time points were processed and edited with the 5.3 version of Freesurfer and the other two time points with FS6. I assume we have to re-run the first two time points with the new versión, but is there a way to preserve the editings?
In the same line, on a transversal study, would it be a lot of bias if most of the subjects of one group are processed with version 5.3 and most of the subjects of the other group with FS6?
Thanks a lot for your time
http://www.cibersam.es/grupos/grupo-de-investigacion/ficha-personal?id=14486Susanna carino!!
On Fri, Apr 13, 2018 at 10:21 AM, Susanna Carmona Cañabate < susannacarmona@gmail.com> wrote:
Dear Freesurfers,
We are running a longitudinal study with 4 time points. The first two time points were processed and edited with the 5.3 version of Freesurfer and the other two time points with FS6. I assume we have to re-run the first two time points with the new versión, but is there a way to preserve the editings?
I think there is - this has been asked quite a lot of times.
In the same line, on a transversal study, would it be a lot of bias if most of the subjects of one group are processed with version 5.3 and most of the subjects of the other group with FS6?
As you know, Doug and Bruce will say that it's a bad idea to mix versions - period. As you know, it's a worse idea to differentially mix versions in 2 groups. Having said that, why not test it by comparing the explained variance of version for your measure of interest (e.g. thickness) and compare it with a variable that distinguishes the groups (e.g. diagnosis)? May be you already did this. I recently did something similar for Laura Pina (attached).
Lots of kisses and let me know if you or your student need any help! -joost
Thanks a lot for your time
Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
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Hi Susanna,
yes, as you feared, you should rerun the first time point so that all time points are run by the same version. Edits should be preserved (although maybe more or probably less edits would be necessary).
And it is really a bad idea to compare across groups where the groups where processed with different software methods (here 5.3 an 6.0). You will not know if the differences that you find come from the methods or are real. Best, Martin
On 13. Apr 2018, at 10:21, Susanna Carmona Cañabate susannacarmona@gmail.com wrote:
Dear Freesurfers,
We are running a longitudinal study with 4 time points. The first two time points were processed and edited with the 5.3 version of Freesurfer and the other two time points with FS6. I assume we have to re-run the first two time points with the new versión, but is there a way to preserve the editings?
In the same line, on a transversal study, would it be a lot of bias if most of the subjects of one group are processed with version 5.3 and most of the subjects of the other group with FS6?
Thanks a lot for your time _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
Thanks to both of you.
On Mon, Apr 16, 2018 at 12:18 PM, Martin Reuter <mreuter@nmr.mgh.harvard.edu
wrote:
Hi Susanna,
yes, as you feared, you should rerun the first time point so that all time points are run by the same version. Edits should be preserved (although maybe more or probably less edits would be necessary).
And it is really a bad idea to compare across groups where the groups where processed with different software methods (here 5.3 an 6.0). You will not know if the differences that you find come from the methods or are real. Best, Martin
On 13. Apr 2018, at 10:21, Susanna Carmona Cañabate < susannacarmona@gmail.com> wrote:
Dear Freesurfers,
We are running a longitudinal study with 4 time points. The first two time points were processed and edited with the 5.3 version of Freesurfer and the other two time points with FS6. I assume we have to re-run the first two time points with the new versión, but is there a way to preserve the editings?
In the same line, on a transversal study, would it be a lot of bias if most of the subjects of one group are processed with version 5.3 and most of the subjects of the other group with FS6?
Thanks a lot for your time _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
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.
freesurfer@nmr.mgh.harvard.edu
-
Joost Janssen -
Martin Reuter -
Susanna Carmona Cañabate