Hello,
I was hoping to get some clarification on how exactly the cortical thickness number is calculated. In the videos, Doug says it's "the distance between the vertex on the white to the vertex on the pial, and you go backwards and forwards to compute the average thickness", and the 2000 paper says "the thickness is computed as the average of this distance measured from each surface to the other".
From what I understand, You find the closest vertex on the pial surface from a given white matter surface vertex, then calculate the distance both ways and take the average. Why is the value not the same both ways, i.e., from white to pial, and from pial to white?
Thanks very much, Eli
Houston Methodist. Leading Medicine. Houston Methodist is ranked by U.S. News & World Report as the No. 1 hospital in Texas for patient care. Houston Methodist is nationally ranked in 8 specialties and is designated as a Magnet hospital for excellence in nursing. Visit us at houstonmethodist.org. Follow us at twitter.com/MethodistHosp and facebook.com/HoustonMethodist. ***CONFIDENTIALITY NOTICE*** This e-mail is the property of Houston Methodist and/or its relevant affiliates and may contain restricted and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender and delete all copies of the message. Thank you.
Hi Eli,
because the "closest" metric isn't symmetric. White-->Pial != pial-->white
cheers Bruce
On Tue, 12 Dec 2017, Rockers, Elijah D. wrote:
Hello,
I was hoping to get some clarification on how exactly the cortical thickness number is calculated. In the videos, Doug says it's "the distance between the vertex on the white to the vertex on the pial, and you go backwards and forwards to compute the average thickness", and the 2000 paper says "the thickness is computed as the average of this distance measured from each surface to the other".
From what I understand, You find the closest vertex on the pial surface from a given white matter surface vertex, then calculate the distance both ways and take the average. Why is the value not the same both ways, i.e., from white to pial, and from pial to white?
Thanks very much, Eli
Houston Methodist. Leading Medicine.
Houston Methodist is ranked by U.S. News & World Report as the No. 1 hospital in Texas for patient care. Houston Methodist is nationally ranked in 8 specialties and is designated as a Magnet hospital for excellence in nursing. Visit us at houstonmethodist.org. Follow us at twitter.com/MethodistHosp and facebook.com/HoustonMethodist.
***CONFIDENTIALITY NOTICE*** This e-mail is the property of Houston Methodist and/or its relevant affiliates and may contain restricted and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender and delete all copies of the message. Thank you.
freesurfer@nmr.mgh.harvard.edu
-
Bruce Fischl -
Rockers, Elijah D.