Researchers edge closer to 3D printing models of life-like organs
The University of Colorado researcher's progress marks an important step toward printing life-like representations of human anatomy that medical professionals can engage with, physically

A team of researchers at the University of Colorado has developed a new strategy for transforming medical images, such as CT or MRI scans, into incredibly detailed digital 3D models. The advance marks an important step toward printing life-like representations of human anatomy that medical professionals can engage with, physically.
The discovery stems from a collaboration between scientists at the University of Colorado’s Boulder campus, and Anschutz Medical Campus that was designed to address a major need in the medical world – surgeons have long used imaging tools, instead of touching and feeling, to plan out their procedures before stepping into the operating room.

“Our method addresses the critical need to provide surgeons and patients with a greater understanding of patient-specific anatomy before the surgery ever takes place,” said Robert MacCurdy, assistant professor in the Paul M. Rady Department of Mechanical Engineering at CU Boulder, and senior author of the paper. His team wants to give doctors a new way to print realistic, and graspable, models of their patients’ various body parts, down to the detail of their tiny blood vessels. In other words – a model of one’s very own kidney entirely fabricated from soft and pliable polymers.
In the study, Robert MacCurdy and his colleagues lay out a method for using scan data to develop maps of organs made up of billions of voxels. The researchers are currently experimenting with how they can use 3D printers to turn those maps into physical models that are more accurate than those available through existing tools.
“In my lab, we look for alternative ways of representation that will feed, rather than interrupt, the thinking process of surgeons,” said CU Anschutz’ Nicholas Jacobson, a clinical design researcher at the Inworks Innovation Initiative, and co-lead of the project. “These representations become sources of ideas that help us and our surgical collaborators see and react to more of what is in the available data.”
Currently, medical professionals try to capture the structures of human organs using “boundary surface” mapping – which, essentially, represents an object as a series of surfaces. “Think of existing methods as representing an entire orange by only considering the exterior orange peel,” said Robert MacCurdy. “When viewed that way, the entire orange is peel.” This research attempts to show the details of the entire orange – inside and out.

The approach begins with a Digital Imaging and Communications in Medicine (DICOM) file – the standard 3D data that CT and MRI scans produce. Using custom software, the researchers convert that information into voxels – essentially slicing an organ into tiny cubes with a volume much smaller than a typical teardrop. According to Robert MacCurdy, the group can do all this without losing any information about the organs in the process – something that is impossible with existing mapping methods.
To test these tools, the team took real scan data of a human heart, kidney, and brain – then created a map for each of those structures. The resulting maps were detailed enough that they could, for example, distinguish between the kidney’s fleshy interior, or medulla, and its outer layer, or cortex – both of which look pink to the human eye.
“Surgeons are constantly touching and interacting with tissues,” said Robert MacCurdy. “So we want to give them models that are both visual and tactile and as representative of what they’re going to face as they can be.”
The project is funded by AB Nexus, a grant program that seeks to spur new collaborations between the two University of Colorado campuses. The published research, titled “Defining Soft Tissue: Bitmap Printing of Soft Tissue for Surgical Planning” can be found here.