Hi Andrea,

Have you looked at http://central.xnat.org? There is at least one project with brain tumor scans (https://central.xnat.org/data/projects/I...), although I'm not sure about the quality and no healthy brains for that specific project. You might try your luck poking around the other projects on that site for healthy brain scans, but its hard to say if the scans will be useful/comparable if they are collected from a different scanner, pulse sequence etc. Hope that helps and maybe others will have suggestions.

Cheers,

Nolan