This process uses the command mri_fill to create a binarized volume. The input is the mri/wm volume and the output is the mri/filled volume. First, the cutting planes are determined to seperate the hemispheres from each other and the pons. Then a seed point located and used to fill each hemisphere. The rh will be filled with a value of 255, and the lh with a value of 127.
Occasionnally, manual intervention is required to define the cutting planes and seed points. To do so, follow these steps:
1.Open the subject's wm volume up in tkmedit. tkmedit subject_name wm
2.View the MNI talairach coordinates. View->Information->MNI Coordinates
3.Select the Corpus Callosum point, on the mid-posterior portion of it. Example: