The contrast will test for the difference in slope of thickness vs NPIDSEV effect between AD and MCI or AD and CN. if it  is positive, it means that AD has a greater slope than MCI or CN. Note that this does not make a statement about the sign of the slopes so you can get a positive result when they are both negative as long as AD is less negative than MCI/CN.

On 7/14/2022 5:44 PM, Adriana Cannizzaro wrote:

        External Email - Use Caution

Hello Dr. Greve,

Please see attached the fsgd and contrast files. I would like to know how to interpret the max value and its directionnality. For example, for this contrast : *g2v1_CN_AD_NPIDSEV.area.lh.fwhm10_group-x-var_neg*, does the negative sign of the max demonstrate that the surface areas of the cuneus and inferior parietal are smaller for the CN group than the AD group as depression severity (NPIDSEV) increases ?

Thank you very much,
Adriana


On Jul 10, 2022, at 5:56 PM, Douglas N. Greve <dgr...@mgh.harvard.edu> wrote:

I'm having problems following your narrative. Can you send the fsgd and contrast files?

On 7/4/2022 5:37 PM, Adriana Cannizzaro wrote:

        External Email - Use Caution

Hello Freesurfers,

We performed a whole-brain analysis using general linear model analysis with FreeSurfer mri_glmfit for neuropsychiatric symptoms (i.e: depression, etc)  to assess their effect on brain’s cortical volume, thickness and area between groups (controls vs mild cognitive impairment,  control vs Alzheimer,  Alzheimer vs mild cognitive impairment).The severity score (level is either 1,2 or 3) of the neuropsychiatric symptoms was included as fixed factors, while MRI parameters (cortical volume, thickness and areas) were regarded as dependent variables.

Thus, these are two sets of results for group_x_var :

For reference :
CN= Control group
MCI= Mild cognitive impairment group
AD: Alzheimer group
NPIDSEV: Depression severity

*Contrast*

        

ClusterNo

        

Max

        

VtxMax

        

Size(mm^2)

        

TalX

        

TalY

        

TalZ

        

CWP

        

CWPLow

        

CWPHi

        

NVtxs

        

WghtVtx

        

Annot

        

Explanation

*g2v1_CN_AD_NPIDSEV.area.lh.fwhm10_group-x-var_neg*

        
        
        
        
        
        
        
        
        
        
        
        
        
        

is there a difference between the group VARiable slopes? contrast 0 0 1 -1. t-test with Group1>Group2 being positive. Note: this is an interaction between group and VARiable


        

1

        

-2.0763

        

158049

        

2847.57

        

-19.8

        

-63.8

        

12.5

        

0.0077

        

0.0066

        

0.0088

        

3957

        

-5537.87

        

cuneus

        

        

2

        

-2.4711

        

147091

        

2469.14

        

-35.3

        

-51.9

        

35

        

0.0205

        

0.0187

        

0.0223

        

5579

        

-7317.77

        

inferiorparietal

        

**

        

        

        

        

        

        

        

        

        

        

        

        

        

        

*g2v1_AD_MCI_NPIDSEV.volume.rh.fwhm10_group-x-var_pos*

        

        

        

        

        

        

        

        

        

        

        

        

        

        

is there a difference between the group VARiable slopes? contrast 0 0 1 -1. t-test with Group1>Group2 being positive. Note: this is an interaction between group and VARiable

**

        

1

        

2.2852

        

91120

        

1748.47

        

63.7

        

-39.7

        

-4.3

        

0.0054

        

0.0045

        

0.0063

        

3263

        

4658.91

        

middletemporal

        


We would like to have more information on the interpretation of these results. Specifically, we would like to know how to interpret the sign of the max coefficient in relation to the difference between the groups on the severity of depression/NPIDSEV and on the volume/area/thickness of the region of interest. Our interpretation for the first result for example was that the difference between the CN and MCI slopes is negative as depression severity increases, however this does not indicate the direction of the slopes regarding the area of the cuneus or the parietal inferior region. Is this correct?

Thank you very much for your help,
Adriana Cannizzaro

_______________________________________________
Freesurfer mailing list
Freesurfer@nmr.mgh.harvard.edu  <mailto:Freesurfer@nmr.mgh.harvard.edu>
*MailScanner has detected a possible fraud attempt from "secure-web.cisco.com" claiming to be* https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer <https://secure-web.cisco.com/1bMh5ilZnmGH-0JAlaGb_j-3vXKksJVd6lP_H43OzXUYUofV4ng0Hzv8Arxriqu3wDztWrN5fBTBc4Wr6jEe5HfNLx0ueOUvMrqLRiSKaU6ubX1BDCLrk8VKb0RTl_nQbatfWcYH-abLVV--_UNHAaVqHzHAM7UgtoHc1RLLndSzCwfMjpkQOtNsSaeDhbTimcgjQdTIPj8fdYirg7_7q3JX6AK4-YoG9hPL3WVnlTDq8aWuilC7FLzhYj64QcHcv7l8MdfTk8NDM_BDy7HpTvT9Iq6D5X5zwplD0JQLAEKJkJw5aabKGXXUTrv_vGXmZ/https%3A%2F%2Fmail.nmr.mgh.harvard.edu%2Fmailman%2Flistinfo%2Ffreesurfer>

_______________________________________________
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 Mass General Brigham Compliance HelpLine at https://www.massgeneralbrigham.org/complianceline <https://www.massgeneralbrigham.org/complianceline> . Please note that this e-mail is not secure (encrypted).  If you do not wish to continue communication over unencrypted e-mail, please notify the sender of this message immediately.  Continuing to send or respond to e-mail after receiving this message means you understand and accept this risk and wish to continue to communicate over unencrypted e-mail.

_______________________________________________
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 Mass General Brigham 
Compliance HelpLine at https://www.massgeneralbrigham.org/complianceline 
<https://www.massgeneralbrigham.org/complianceline> .
Please note that this e-mail is not secure (encrypted).  If you do not wish to 
continue communication over unencrypted e-mail, please notify the sender of 
this message immediately.  Continuing to send or respond to e-mail after 
receiving this message means you understand and accept this risk and wish to 
continue to communicate over unencrypted e-mail. 

Reply via email to