Derived from MRI vrml file from McGill University (http://audilab.bmed.mcgill.ca/~daren/3Dear/inn1.html), I converted the vrml to stl, carried out 25% mesh reduction using Rhino3D, played with the orientation (there is only one orientation that prints well even with support). Printed it on a Replicator with 5 shells and 5% infill in ABS on a raft with exterior support.