open-discussion
open-discussion > Beijing_Zang anatomical pixel dimensions
Feb 9, 2010 11:02 PM | Timothy Herron
Beijing_Zang anatomical pixel dimensions
Hello,
I am concerned that the anatomical image headers for all of the Beijing_Zang data contain incorrect pixel dimensions. In particular, the y and z dimension (ant-pos and sup-inf) axes appear squashed in both the anonymized and skullstripped images. When I normalized either of these anatomicals to MNI space (ICBM-152 in SPM5) the y-z (saggital view) area was expanded by a mean factor of ~2.1 rather than the more reasonable ~1.4 factor that I got with the 19 other fcon_1000 dataset anatomicals that I have processed so far. Perhaps the correct pixel dimensions are approximately 1.33 x 1.2 x 1.2 rather than the stated 1.33 x 1.0 x 1.0? The fit of my normalization seems reasonably good, and the Beijing_Zang anatomicals are of good quality, so I don't think that I have a normalization problem (spm5 normalized all of them without incident). I also obtained an unusually low total brain area for the Beijing_Zang anatomicals when I do a segmentation of the anatomicals and sum the segmentation probabilities for WM and GM.
Thanks,
Timothy J. Herron
I am concerned that the anatomical image headers for all of the Beijing_Zang data contain incorrect pixel dimensions. In particular, the y and z dimension (ant-pos and sup-inf) axes appear squashed in both the anonymized and skullstripped images. When I normalized either of these anatomicals to MNI space (ICBM-152 in SPM5) the y-z (saggital view) area was expanded by a mean factor of ~2.1 rather than the more reasonable ~1.4 factor that I got with the 19 other fcon_1000 dataset anatomicals that I have processed so far. Perhaps the correct pixel dimensions are approximately 1.33 x 1.2 x 1.2 rather than the stated 1.33 x 1.0 x 1.0? The fit of my normalization seems reasonably good, and the Beijing_Zang anatomicals are of good quality, so I don't think that I have a normalization problem (spm5 normalized all of them without incident). I also obtained an unusually low total brain area for the Beijing_Zang anatomicals when I do a segmentation of the anatomicals and sum the segmentation probabilities for WM and GM.
Thanks,
Timothy J. Herron
Threaded View
Title | Author | Date |
---|---|---|
Timothy Herron | Feb 9, 2010 | |
Yu-Feng Zang | Feb 11, 2010 | |
Xi-Nian Zuo | Mar 27, 2010 | |