Hi All,
Is the following T1 sequence suitable for surface generation?
"T1-weighted 3D SPGR (echo time 5 minimum; repetition time = 24 msec; flip angle = 30; field of view = 24 centimeters; slice thickness = 3 millimeters) collected in the axial plane."
It's that 3 mm slice thickness that most concerns me. The sequence was not initially intended for surface reconstruction, but I've run a few volumes through recon-all and they've turned out better than I had expected. We're primarily using the output for automated ROI generation, but I'm wondering if the cortical thickness and volume estimations from such an acquisition are suitable for further analysis (i.e., group comparisons, correlations).
-SS
Hi Scott
we don't usually recommend having any voxel dimension > 1.5mm, and try to be closer to 1mm iso. I'm surprised that your results have been positive so far. I doubt the thickness estimates will be terribly sensitive, but there's nothing but compute time to be lost by trying.
cheers Bruce
On Thu, 10 Feb 2011, Scott Sorg wrote:
Hi All,
Is the following T1 sequence suitable for surface generation?
"T1-weighted 3D SPGR (echo time 5 minimum; repetition time = 24 msec; flip angle = 30; field of view = 24 centimeters; slice thickness = 3 millimeters) collected in the axial plane."
It's that 3 mm slice thickness that most concerns me. The sequence was not initially intended for surface reconstruction, but I've run a few volumes through recon-all and they've turned out better than I had expected. We're primarily using the output for automated ROI generation, but I'm wondering if the cortical thickness and volume estimations from such an acquisition are suitable for further analysis (i.e., group comparisons, correlations).
-SS
freesurfer@nmr.mgh.harvard.edu
-
Bruce Fischl -
Scott Sorg