3D Printing Filaments for Customizable Iodine-Infused Spectral CT Phantoms

3D printing filaments for 3D printing phantoms with controlled iodine concentrations for precise, adjustable spectral CT imaging research and calibration.
Problem:
Traditional CT imaging phantoms act as physical proxies for human tissue and anatomy, but they are expensive, rigid, and limited in both achievable iodine concentrations and geometric complexity. This restricts realistic simulation of tissues, lesions, and nodules and, in turn, slows the development and validation of advanced imaging algorithms and contrast-based techniques.
Technology:
In order to enable better patient-specific contrast-enhanced phantoms, the inventors implement a “good–bad solvent” technique. Here, the “good solvent” facilitates inorganic iodine diffusion into the polymer matrix, and the “bad solvent” preserves the polymer structure, allowing for pellet formation. After evaporating the solvents under heat and vacuum, the iodine-enriched pellets are extruded into 1.75 mm rigid filaments for 3D printing. Using a dual-extruder system, a filament containing 10 mg/mL iodine and a second standard Polylactic Acid (PLA) filament can then be programmed to simulate varying iodine concentrations in the same phantom, reproducing the heterogeneity of soft tissues. Use of the iodine-infused filaments can be further combined with the PixelPrint technology to produce patient-specific phantoms with accurate geometry, density, and iodine distribution — enabling more rigorous calibration, testing, and innovation in spectral CT imaging.
Advantages:

Tunable iodine concentrations from 0.7 to 10.4 mg/mL within a single phantom
CT attenuation that scales predictably with iodine infill ratio, enabling quantitative calibration
Lower cost than commercial anthropomorphic phantoms
Compatible with PixelPrint technology to produce fully patient-specific phantom geometries

Stage of Development:

Prototype

Calibration cubes fabricated using IodinePrint. (A) Photograph of four 3D-printed cubes with increasing infill ratios, visibly demonstrating changes in optical density. (B) Iodine density maps of the cubes, showing increased signal corresponding to higher iodine concentrations. (C) HU attenuation curves plotted across virtual monoenergetic energy levels (50–200 keV) comparing the IodinePrint material (orange), normalized IodinePrint (green), and a commercial iodine insert (blue). The close match between the normalized IodinePrint and the commercial iodine insert demonstrated consistent spectral behavior, validating the suitability of the filament for quantitative iodine imaging.
Intellectual Property: