Tissue equivalence of 3D printing materials with respect to attenuation and absorption of X‐rays used for diagnostic and interventional imaging

Introduction Three‐dimensional printing is a promising technology to produce phantoms for quality assurance and dosimetry in X‐ray imaging. Crucial to this, however, is the use of tissue equivalent printing materials. It was thus the aim of this study to evaluate the properties of a larger number of commercially available printing filaments with respect to their attenuation and absorption of X‐rays. Materials and methods Apparent kerma attenuation coefficients (AKACs) and absorbed doses for different X‐ray spectra (tube voltages, 70–140 kV) were measured and simulated by Monte‐Carlo computations for a larger number of fused‐deposition‐modeling (FDM) materials. The results were compared with the respective values simulated for reference body tissues. In addition, the properties of polylactide acid samples printed with reduced infill densities were investigated. Results Measured and simulated AKACs and absorbed doses agreed well with each other and in case of AKACs also with attenuation coefficients derived from the reference database of the National Institute of Standards and Technology (NIST). For lung, adipose, muscle, and bulk soft tissue as well as for spongiosa (cancellous bone), printed materials with equivalent attenuation as well as absorption properties could be identified. In contrast, none of the considered printed materials was equivalent to cortical bone. Conclusion Several FDM materials have been identified as well‐suited substitutes for body tissues in terms of the investigated material characteristics. They can therefore be used for in‐house production of individualized and task‐specific phantoms for image quality assessment and dose measurements in X‐ray imaging.