Hi Pedro,
Thanks for your reply,
Actually I am using 6 different sequences for scanning the same subject, so
a small part of the difference could be because of randomness, but there
should be a way to select the best scan from these 6 different scans. I need
to know how to select the best.
any su
Hi Sima,
you could compute the contrast-to-noise ratio between gray and white,
which will give you some idea. The overall optimization is very difficult
though as there are factors like distortion, contrast uniformity, etc
cheers
Bruce
On Fri, 4 Sep 2009, sima chalavi wrote:
Hi Pedro,
Hi Sima,
it's hard to say just from the tiffs. A couple of things you can look at:
run mris_euler_number on the lh.orig.nofix and the rh.orig.nofix. Better
sequences should result in bigger (less negative) euler numbers.
Plot the intensity distributions of the gray matter, CSF and the white
Dear Bruce,
Thanks so much for your email,
I ran mris_euler_number and mri_cnr (see attachment) according to your
advice, it is already clear for us to remove G02 because of having too small
Euler number. It is also clear that for this particular scanner the G05_H_11
sequence is the best.
For our
Hi Sima,
you should also make sure that the surfaces are visually accurate (that
is, the white and pial surfaces lie at the true boundaries). If that's the
case then either 03 or one of the 05s is the next best. For the
distributions, you can use the aparc+aseg.mgz to extract the correct voxel
