External Email - Use Caution
Sorry to bump this post up! I understand that everyone is busy, but I'm really
hoping to get some feedback on my questions. Any thoughts or suggestions would
be greatly appreciated! Thanks in advance!
原始邮件
发件人： "Alex" <free_lear...@foxmail.com>
发件时间： 2024年11月13日 00:54
收件人： "freesurfer" <freesurfer@nmr.mgh.harvard.edu>
主题： How to interpret the vertex-wise area metric?
Dear FreeSurfer experts,
I have a question about the interpretation of the vertex-wise area metric. For
instance, if Vertex A had a larger area than Vertex B, then what's the
difference between Vertex A and Vertex B biologically?
Based on my simple (probably wrong) understanding of the surface reconstruction
process, the initial surface was created based on the GM-WM boundary voxels, in
which the face of a voxel was divided into two triangles and the area of the
triangles was equal. But after the refinement of the initial surface, the
triangle area was not uniform any more. So what factors may explain the
expansion or contraction of the surface triangles? I believe these factors may
help me understand the vertex-wise area metric. Maybe I should treat the vertex
and the triangles around it as a whole, which is the unit of comparison. For
instance, the Vertex A having a larger area means the area of triangels around
Vertex A is larger. This kind of interpretation would make the comparsion
between Vertex A and B biologically meaningless.
From another perspective, in the voxel-based morphometry (VBM), the voxel size
is fixed and the volume is the proportion or probability of GM (or other tissue
types) in the voxel. In the surface case, if the triangle size is kept fixed,
the area is proportial to the number of triangles, which is conceptually
similar to the VBM approach. Why FreeSurfer did not choose this kind of
approach? Sorry if this question is not reasonable, as I did not have a strong
technical background.
Best,
Yang Hu_______________________________________________
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.
