Boston Children's Hospital physicians report the first cases of children benefiting from 3D printing of their anatomy before undergoing high-risk brain procedures.  Three of the four children had arteriovenous malformations (AVMs), in which tangles of arteries and veins connect abnormally, and were treated surgically.

http://www.wdrb.com/story/29680355/3d-printing-helps-doctors-rehearse-complex-brain-procedures