Hi freesurfer team, I am wondering if there would be a way to process a glm analysis between 2 surfaces from different modalities within one group of subjects.
For example, within one population of patients, we would like to see if there is a spatial relationship between cortical thickness and another metrics (DTI metrics for example). What we have done so far is compute the mean cortical thickness for each parcellation, the mean FA for each parcellation, and we did a linear regression with all the subjects of our group. Would there be a way to do that at the vertex level instead of a whole region level? From what I understood, when we use glmfit, the regressors that we can put are single values like age, group, cognitive testing etc, but maybe not an entire surface? Thanks a lot
Best, Celine
Hi Celine, use mri_glmfit with the --pvr option (pvr = per-vertex regressor) doug
On 10/30/2013 10:20 AM, celine@nmr.mgh.harvard.edu wrote:
Hi freesurfer team, I am wondering if there would be a way to process a glm analysis between 2 surfaces from different modalities within one group of subjects.
For example, within one population of patients, we would like to see if there is a spatial relationship between cortical thickness and another metrics (DTI metrics for example). What we have done so far is compute the mean cortical thickness for each parcellation, the mean FA for each parcellation, and we did a linear regression with all the subjects of our group. Would there be a way to do that at the vertex level instead of a whole region level? From what I understood, when we use glmfit, the regressors that we can put are single values like age, group, cognitive testing etc, but maybe not an entire surface? Thanks a lot
Best, Celine
Thank you. For the contrast, if I don't enter any other regressor, then it will be 1 -1? Celine
Hi Celine, use mri_glmfit with the --pvr option (pvr = per-vertex regressor) doug
On 10/30/2013 10:20 AM, celine@nmr.mgh.harvard.edu wrote:
Hi freesurfer team, I am wondering if there would be a way to process a glm analysis between 2 surfaces from different modalities within one group of subjects.
For example, within one population of patients, we would like to see if there is a spatial relationship between cortical thickness and another metrics (DTI metrics for example). What we have done so far is compute the mean cortical thickness for each parcellation, the mean FA for each parcellation, and we did a linear regression with all the subjects of our group. Would there be a way to do that at the vertex level instead of a whole region level? From what I understood, when we use glmfit, the regressors that we can put are single values like age, group, cognitive testing etc, but maybe not an entire surface? Thanks a lot
Best, Celine
-- 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
Probably 0 1, since you are not interested in the offset. You would use one modality as input (y) and the other as the pvr. glmfit will then solve the model y = offset + slope*pvr at each voxel, fitting the offset and slope. You'll then want to test the slope doug
On 10/30/2013 11:24 AM, celine@nmr.mgh.harvard.edu wrote:
Thank you. For the contrast, if I don't enter any other regressor, then it will be 1 -1? Celine
Hi Celine, use mri_glmfit with the --pvr option (pvr = per-vertex regressor) doug
On 10/30/2013 10:20 AM, celine@nmr.mgh.harvard.edu wrote:
Hi freesurfer team, I am wondering if there would be a way to process a glm analysis between 2 surfaces from different modalities within one group of subjects.
For example, within one population of patients, we would like to see if there is a spatial relationship between cortical thickness and another metrics (DTI metrics for example). What we have done so far is compute the mean cortical thickness for each parcellation, the mean FA for each parcellation, and we did a linear regression with all the subjects of our group. Would there be a way to do that at the vertex level instead of a whole region level? From what I understood, when we use glmfit, the regressors that we can put are single values like age, group, cognitive testing etc, but maybe not an entire surface? Thanks a lot
Best, Celine
-- 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
freesurfer@nmr.mgh.harvard.edu
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celine＠nmr.mgh.harvard.edu -
Douglas N Greve