3D Printing in Interventional Radiology

Purpose: To learn about the basic workflow of three-dimensional (3D) printing, the materials needed for printing a 3D model, and the applications of 3D printing in interventional radiology (IR)

Materials and Methods: 3D printing, or additive manufacturing, provides an opportunity to produce models capable of communicating tactile feedback and tangible depth information in relation to the anatomical and pathological state of our patients. The process of 3D printing is divided into three steps: image acquisition, image postprocessing, and 3D printing. In image acquisition, Digital Imaging and Communications in Medicine (DICOM) images are acquired through computed tomography or magnetic resonance imaging. In image postprocessing, DICOM images are processed via segmentation to isolate the desired anatomy. Segmentation occurs through specialized open-source (e.g., 3D slicer) or proprietary (e.g., Mimics, Materialise NV, Belgium) software by selecting ranges within the Hounsfield scale. The reconstructed model is then developed into an .STL or .OBJ file format. As a final step, the reconstructed files are input into a slicing software that produces a .gcode file. Depending on the level of detail and speed required by the user, the .gcode is input into printers that use either filament or vat photopolymerization to build the structure one layer at a time. After the model is printed, it is prepared for clinical use. The products required for 3D printing are DICOM images of interest to be printed, segmentation and slicing software, and a 3D printer. Open-source software is available through 3D slicer and Cura. 3D printers are selected based on the models intended use. They range from filament, liquid-based, or powder-based materials and are selected based on the intended use and complexity of the model.

Results: Uses of 3D printing in IR can be divided into clinical applications in various systems of the body, bioprinting to create biomedical parts that maximally imitate the natural tissue characteristics, patient education, medical education, and applications in various fields of research.

Conclusions: Successful application of 3D printing in various fields will likely change the practice of medicine. Interventional radiologists can take charge and lead this revolution by understanding the process required to create quality 3D prints. Its use can improve our understanding of individual anatomy and pathology and help in providing the best possible personalized clinical care.