Hello, Freesurfer experts:

 

We are extracting the average cortical thickness of each hemisphere for every subject using mris_anatomical_stats. We found that for one subject (attached below), the thickness measures are quite similar but the ¡°intrinsic curvature index¡± differs drastically between left/right hemispheres. Will this curvature index affect the validity of our thickness measure?

 

 ***the left hemisphere

mris_anatomical_stats -l lh.cortex.label -f subject1l.txt subject1 lh

limiting computations to label lh.cortex.label.

reading volume /usr/local/freesurfer/subjects/subject1/mri/wm.mgz...

reading input surface /usr/local/freesurfer/subjects/subject1/surf/lh.white...

reading input pial surface /usr/local/freesurfer/subjects/subject1/surf/lh.pial...

reading input white surface /usr/local/freesurfer/subjects/subject1/surf/lh.white...

structure is "lh.cortex.label"

number of vertices                      = 157421

total surface area                      = 102165 mm^2

total gray matter volume                = 290073 mm^3

average cortical thickness              = 2.488 mm +- 0.694 mm

average integrated rectified mean curvature     = 0.170

average integrated rectified Gaussian curvature = 0.105

folding index                           = 4980

intrinsic curvature index               = 592.3

 

 

***the right hemisphere

mris_anatomical_stats -l rh.cortex.label -f subject1r.txt subject1 rh

limiting computations to label rh.cortex.label.

reading volume /usr/local/freesurfer/subjects/subject1/mri/wm.mgz...

reading input surface /usr/local/freesurfer/subjects/subject1/surf/rh.white...

reading input pial surface /usr/local/freesurfer/subjects/subject1/surf/rh.pial...

reading input white surface /usr/local/freesurfer/subjects/subject1/surf/rh.white...

structure is "rh.cortex.label"

number of vertices                      = 158401

total surface area                      = 102285 mm^2

total gray matter volume                = 291519 mm^3

average cortical thickness              = 2.482 mm +- 0.707 mm

average integrated rectified mean curvature     = 0.173

average integrated rectified Gaussian curvature = 0.299

folding index                           = 5756

 

 

Thanks in advance

 

Karl