Stefan, You can make a mask out of the segmented image and apply that mask to your other image. If you go to image calc and click on the help there is a discription of how to do this. Good luck, Paul Laurienti Stefan Steens wrote: > Dear members of the list, > I want to use one segmented structural image series (img1: CSF, white > matter, grey matter) to oppose to another (coregistered) image series > (img2: has poor grey/white contrast itself), to obtain segmented images > from img2. I already have the segmented img1. I assume it's possible to do > this, probably with ImCalc. I'm pretty new on SPM, and cannot find the > right way. Anyone has experience with this? > Best regards > > Stefan Steens > Leiden University Medical Center > Leiden, the Netherlands