World’s first high-resolution brain developed using a 3D printer – 2024-03-21 18:12:55

New model can advance research into neurodegenerative diseases

Vienna (OTS) – In a joint project between the MedUni Vienna and the TU Vienna, the world’s first 3D printed “brain phantom” was developed, which is modeled on the structure of brain fibers and can be imaged using a special variant of magnetic resonance imaging (dMRI). As a scientific team led by MedUni Vienna and TU Vienna has now shown in a study, these brain models can be used to advance research into neurodegenerative diseases such as Alzheimer’s, Parkinson’s and multiple sclerosis. The research was published in the journal “Advanced Materials Technologies”.

Magnetic resonance imaging (MRI) is a widely used diagnostic imaging procedure that is primarily used to examine the brain. MRI can be used to examine the structure and function of the brain without the use of ionizing radiation. In a special variant of MRI, diffusion-weighted MRI (dMRI), the direction of the nerve fibers in the brain can also be determined. However, the correct determination of the nerve fiber direction at the crossing points of nerve fiber bundles is very difficult because there are overlaps of nerve fibers with different directions. In order to further improve the process and test analysis and evaluation methods, an international team in collaboration with the Medical University of Vienna and the TU Vienna developed a so-called “brain phantom” that was produced using a high-resolution 3D printing process.

Tiny cube with micro channels
Researchers from the Medical University of Vienna as MRI experts and the TU Vienna as 3D printing experts worked closely with colleagues from the University of Zurich and the University Hospital Hamburg-Eppendorf. Already in 2017, a two-photon polymerization printer was developed at the TU Vienna that enables highly scaled printing. In the course of this, we also worked on brain phantoms as an application together with the Medical University of Vienna and the University of Zurich. The resulting patent forms the basis for the brain phantom that has now been developed and is looked after by the research and transfer support of the TU Vienna.

Visually, this phantom doesn’t have much in common with a real brain. It is much smaller and shaped like a cube. Inside there are the finest microchannels filled with water, the size of individual cranial nerves. The diameters of these channels are five times thinner than a human hair. In order to imitate the fine network of nerve cells in the brain, the research team led by the first authors Michael Woletz (Center for Medical Physics and Biomedical Engineering, MedUni Vienna) and Franziska Chalupa-Gantner (3D Printing and Biofabrication Research Group, TU Vienna) used one rather unusual 3D printing method: two-photon polymerization. This high-resolution method is primarily used for printing microstructures in the nano and micrometer range – not for printing three-dimensional structures in the cubic millimeter range. In order to create phantoms of a suitable size for dMRI, researchers at the TU Vienna worked on upscaling the 3D printing process and enabling the printing of larger objects with high-resolution details. Thanks to the upscaled 3D printing, the researchers obtain very good models that, when viewed using dMRI, make it possible to assign different nerve structures. Michael Woletz compares this approach to improving the diagnostic capabilities of dMRI with the way a cell phone camera works: “We see the greatest progress in photography with cell phone cameras not necessarily in new, better lenses, but in the software that improves the images captured. It’s similar with dMRI: Using the newly developed brain phantom, we can adjust the analysis software much more precisely, thereby improving the quality of the measured data and reconstructing the brain’s neural architecture more precisely.”

Brain phantom trains analysis software
The authentic replication of characteristic nerve structures in the brain is therefore important in order to “train” the dMRI analysis software. The use of 3D printing allows you to create diverse and complex designs that can be changed and customized. The brain phantoms depict areas in the brain that generate particularly complex signals and are therefore difficult to analyze, such as crossing nerve pathways. In order to calibrate the analysis software, the brain phantom is examined with dMRI and the measured data is analyzed as in a real brain. Through 3D printing, the design of the phantoms is precisely known and the results of the analysis can be checked. The MedUni Vienna and TU Vienna were able to show that this works as part of their joint research work. With the help of the developed phantoms, dMRI can be improved, which can benefit the planning of operations and research into neurodegenerative diseases such as Alzheimer’s, Parkinson’s and multiple sclerosis.

Despite the proof of concept, the team continues to face challenges. The biggest challenge currently is scaling the method: “The high resolution of two-photon polymerization enables the printing of details in the micro and nanometer range and is therefore very suitable for imaging cranial nerves. At the same time, with this technology it takes a correspondingly long time to print a cube several cubic centimeters in size,” explains Chalupa-Gantner. “We therefore aim not only to develop even more complex designs, but also to further optimize the printing process itself.”

Publikation: Advanced Materials Technologies
Toward Printing the Brain: A Microstructural Ground Truth Phantom for MRI;
Michael Woletz, Franziska Chalupa-Gantner, Benedikt Hager, Alexander Ricke, Siawoosh Mohammadi, Stefan Binder, Stefan Baudis, Aleksandr Ovsianikov, Christian Windischberger, Zoltan Nagy;

Questions & Contact:

medical university Vienna
Mag. Johannes Angerer
Head of Communications and Public Relations
Tel.: +43 1/ 40 160-11501
Email: pr@meduniwien.ac.at
Spitalgasse 23, 1090 Vienna
www.meduniwien.ac.at/pr

technical University of Vienna
Sarah Link, MA
PR and marketing
Tel: +43 664 60588 2412
E-Mail: sarah.link@tuwien.ac.at
Karlsplatz 13, 1040 Vienna