[Freesurfer] question regarding the comparison of two methods: repost

2011-05-03 Thread Jacobs H (NP)
 

Dear FreeSurfers,

We are comparing two methods to measure the volume of a subcortical structure 
(our method and FreeSurfer). 
We want to compare them spatially, by doing a voxel-based analyses.
We thought to isolate the structure from the aseg.mgh as well as our own 
structure. Then we smoothed both data sets.
Now we are trying to convert the structure from our method to FreeSurfer space 
(256 x 256). 
Then, our plan was to put all the data of the structures of both methods all 
the subjects together (4D) and to run mri_glmfit (comparing method one with 
method two).
Does this seems logically?

But, we were wondering how we should deal with the registration. Because this 
is in volume space, we cannot register it to the sphere. 
Registration to the fsaverage may not be very accuracte.
Do you have any ideas how to solve this issue?

Thank you very much.
Best

Heidi Jacobs


Heidi Jacobs, MSc.
PhD student
Faculty of Health, Medicine and Life Sciences School for Mental Health and 
Neurosciences Alzheimer Center Limburg Division Cognitive Neuropsychiatry and 
Clinical Neurosciences h.jac...@maastrichtuniversity.nl 
mailto:h.jac...@maastrichtuniversity.nl
www.maastrichtuniversity.nl http://www.maastrichtuniversity.nl/

Dr. Tanslaan 12, 6229 ET Maastricht
P.O. Box 616, 6200 MD Maastricht, The Netherlands T +31 43 38 84 126 F +31 43 
38 84 092




___
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.



Re: [Freesurfer] question regarding the comparison of two methods: repost

2011-05-03 Thread Bruce Fischl
Hi Heidi,

why do they have to be in a common space? You aren't comparing across 
subjects, just within subject across method. Or are you trying to make maps 
of accuracy? That will be hard to do unless you use our coordinate system 
to do your segmentation, which I assume you do not. In any case, 
mri_extract_label will take a transform such as the talairach.m3z, which 
will map a label into our atlas coordinates.

cheers
Bruce


On Tue, 3 May 2011, Jacobs H 
(NP) wrote:



 Dear FreeSurfers,

 We are comparing two methods to measure the volume of a subcortical structure 
 (our method and FreeSurfer).
 We want to compare them spatially, by doing a voxel-based analyses.
 We thought to isolate the structure from the aseg.mgh as well as our own 
 structure. Then we smoothed both data sets.
 Now we are trying to convert the structure from our method to FreeSurfer 
 space (256 x 256).
 Then, our plan was to put all the data of the structures of both methods all 
 the subjects together (4D) and to run mri_glmfit (comparing method one with 
 method two).
 Does this seems logically?

 But, we were wondering how we should deal with the registration. Because this 
 is in volume space, we cannot register it to the sphere.
 Registration to the fsaverage may not be very accuracte.
 Do you have any ideas how to solve this issue?

 Thank you very much.
 Best

 Heidi Jacobs


 Heidi Jacobs, MSc.
 PhD student
 Faculty of Health, Medicine and Life Sciences School for Mental Health and 
 Neurosciences Alzheimer Center Limburg Division Cognitive Neuropsychiatry and 
 Clinical Neurosciences h.jac...@maastrichtuniversity.nl 
 mailto:h.jac...@maastrichtuniversity.nl
 www.maastrichtuniversity.nl http://www.maastrichtuniversity.nl/

 Dr. Tanslaan 12, 6229 ET Maastricht
 P.O. Box 616, 6200 MD Maastricht, The Netherlands T +31 43 38 84 126 F +31 43 
 38 84 092




 ___
 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.