Hello,
as I was working on some things (possibly another question later on)
with talairach coordinates and I have run into a problem. I tried to
use img2talcoord to get tal coordinates for a list of voxels in the
original space. here is the command I have used...
img2talcoord -tal standard -img example_func -xfm
example_func2standard.mat -vox -flirt original_coords.txt >
mni_coords.txt
I have run this within the reg/ folder, and original_coords.txt is a
modified Imax_zstat1.txt file from the same analysis. I just wanted to
confirm that I will get the same coordinates as are reported in the
feat report (in cluster_zstat1_tal.html, and listed in
Imax_zstat1_tal.txt). But I do not get the same numbers! Here are just
a few coordinates from the list...
original coordinates (voxels)
30 5 3
35 8 0
30 6 1
27 4 5
corresponding tal coordinates from Imax_zstat1_tal.txt (result of feat
analysis)
6.95 -92.4 19.1
-9.38 -85.7 2.32
6.96 -91.3 8.14
16.8 -93.7 29.8
and here are the coordinates output by img2talcoord
6.95002 60.3709 19.1
-9.37855 53.7371 2.3233
6.96059 59.3127 8.13768
16.839 61.7015 29.7874
As you can see, the y coordinates are way off. Why? I have
doublechecked all my files: input functionals are in the same
orientation (Posterior on top) as the standard file (mni standard);
there is nothing out of the ordinary in the header files for the
functional as well as the high res used in the registration. And the
registration results are very good. Have I just used img2talcoord
incorrectly, or is there something else that I am missing?
Thank you!
Zrinka Bilusic-Vezmar
UCLA Brain Mapping
660 Charles Young Drive South
Los Angeles, CA 90095
310-794-5060
[log in to unmask]
www.brainmapping.org
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