[Mristudio-users] ImgVal Calculation

[hjyu]

I have a question regarding the ImgVal calculation under statistical
profile for fiber tracking.  I got very different mean FA values
(differences ranging from 0.04 to 0.1)  when I tried these two methods
(keeping all parameters consistent and same version of DTI):
1.       Load previously saved fiber track (binary) into DTI studio,
click on fiber statistics and I have  for Mean of ImgVal and Std. of
ImgVal
2.       Using MATLAB, apply the same binary fiber track onto FA image
(analyze format), calculate mean/std values for all the pixels/voxels
belonging to this fiber track
How are these mean ImgVal calculated?  I assume it is just a mean values
for all the pixels/voxels that are contained in the fiber track of
interest.
 
Thanks in advance for your help.
 
HJ