I have been working on getting a volume created by mris_fill from the pial surfaces exported to be used in a dipole/current density analysis software package.  I have succeeded in being able to concat both halves and have gotten the volumes loaded successfully into the software, but I need a bit better resolution.  My question is this:  Is there a way to erode the pial surface either before or after its creation?  I need maybe 0.5 – 1mm of erosion so that each sulci is a bit more defined.  The surface looks great, but in order to consider the grey matter in each sulci for the dipole/current density calculation, each sulci needs to be distinct.  The only way that I can think about it is by eroding the grey matter by 0.5-1mm before I use the mris_fill command.  I am not sure if this is even possible, or if it is where it would need to be done.  Thanks for any help.

Cochrane