Hi everyone,
I generated the wj* (warped jacobian determinants) files from the DBM protocol in CAT12. My question is about the meaning of the voxel-wise value on wj* files. The voxel intensity varies between ~0.5 (darker areas) and 2.8 (lighter areas) and every voxel's value is supposed to express local volume changes. Therefore I am asking myself the meaning of the lower values versus higher values. Do lower values represent that the voxel in the individual scan had to be contracted to be normalized to the template, that voxels with higher values (2.5 for example) are the ones in which the voxel underwent more deformation (expansion) to be normalized to the template (and therefore may represent atrophy in the patient's scan)? Is there a boundary at which a voxel value would mean that the deformation shifts from contraction or expansion (ie 0)?
A good understanding of the meaning of the individual value would be important for me. I understand that my question may be a bit wide.
Thank you very much for your help,
Yuri
|