Bitmap-Based 3D Printed Models Are More Accurate

A new study describes how extremely detailed physical three-dimensional (3D) models can be generated directly from volumetric data stacks.

Developed by Isomics (Cambridge, MA, USA), the Max Planck Institute of Colloids and Interfaces (MPIKG; Potsdam, Germany), the Wyss Institute for Biologically Inspired Engineering (Boston, MA, USA), and other institutions, the new 3D modeling technique is designed to solve the problem of current .stl surface mesh file formats, which are created using traditional image thresholding and isosurface extraction. Since such workflows are extremely time consuming, the resulting 3D-printed models can fail to accurately depict anatomical details of interest.

The new method uses a bitmap-based workflow that does not require a data segmentation step, and thus capable of generating rapid and highly accurate physical models directly from volumetric data. The threshold-free approach bypasses isosurface creation and traditional mesh slicing algorithms, limited file sizes, and artificial filtering or obscuring of data. In addition, using binary bitmap slices as input to the 3D printers allows for physical rendering of functional gradients native to the volumetric data sets, such as stiffness and optical transparency, providing biomechanically accurate models. The study was published on June 1, 2018, in 3D Printing and Additive Manufacturing.

“By lowering barriers to the visualization of fine details in biorealistic 3D-printed models, we hope to broaden access to this technology for a wide range of medical professionals and patients,” concluded senior author James Weaver, PhD, of the Wyss Institute, and colleagues. “When combined with high-resolution biological imaging data, multi-material medical 3D printing has the potential to improve treatment, enhance communication, and open new research avenues in precision medicine.”

3D-printed models for pre-surgical planning are used in almost all surgical subspecialties, allowing for a precise planning and simulation of the surgical approach, incision, and hardware sizing and placement. Physical 3D models can also serve as cutting guides for resection and as templates for the shaping of reconstruction hardware, implants, and prostheses so as to fit a patient's anatomy. 3D printing can also capture patient variability for education and training and provide easily interpretable visual guides for improving doctor–patient communication.

Related Links:
Isomics
Max Planck Institute of Colloids and Interfaces
Wyss Institute for Biologically Inspired Engineering