Oh this? Nothing. Just the 3D-printed skeleton of a living, breathing animal.

This is what you get when you take data from a CT scan and convert it into a format that can be read by a 3D-printer. It's a skeleton. But not just any skeleton. The 3D model you see here was printed while the rat whose bones it's based on was still alive. Intact. Still wrapped in muscle, skin and fur.

It's a nifty trick, removing an animal's bones without taking its life (let alone making an incision), and it's one Evan Doney – a bioengineering student in the lab of Matthew Leevey at Notre Dame – thinks could prove incredibly useful. He recounts the conversion process (which he developed with various freeware programs) and discusses potential applications in the Journal of Visualized Experiments. Wired's Greg Miller gives a tidy summary of the latter:

Similarly made 3-D models based on CT scans from individual patients could help surgeons prepare for tricky surgeries, such as removing hard-to-access tumors in or around the airway, Leevy says. “Ideally they’d have the whole head right in front of them, with all the anatomy preserved, and the tumor printed out in a different color of plastic within the model.”

The models could be a boon for education too. A high-quality cast of a human skull costs hundreds of dollars, and a complete skeleton can set you back thousands, Leevy notes. 3-D printed skulls would be far cheaper. “At Notre Dame, there are 100 kids in anatomy class and they have to share 5 skulls,” he said. “For 10 to 20 bucks they could each have their own skull to take back to their dorm to study.”

Read more at Wired. Check out Doney and his colleagues' research, and how-to guide, over at JOVE.