Author: Gisell Ruiz Boiset, Paulo ROBERTO Costa, Elsa Bifano Pimenta 👨🔬
Affiliation: University of São Paulo (USP), Institute of Physics 🌍
Purpose: This study evaluates the similarity between the linear attenuation coefficients of soft tissues and 3D printing materials in diagnostic imaging range using the Euclidean distance approach.
Methods: The linear attenuation coefficient of a set of commercial 3D printing materials were experimentally determined using X-ray spectrometry and compared with those of different soft tissues. The energy range used for the evaluation was 15 to 150 keV. The linear attenuation coefficients of 3D printing materials (ABS, ABSpremiumNude, ABSgrey, Flexible80A, HIPSred, HIPSwhite, PETG, PLA/Al, PLAorange, TangoBlackPlus, Tough, TPU, VeroClear and Wood) were compared with soft tissues referenced in ICRU Report 44 using Euclidean distance metric.
Results: The breast tissue exhibits alignment with polymers, shifting from PLA/Al at 15 keV (2.0%) to Tough at 60 keV (0.8%). The heart tissue corresponds with Wood at 20 keV (25.5%) and Tough at 40 and 60 keV, exhibiting variations between 0.7%–18.9%. The percentage variations in the lung tissue range between 22.6% to 30.1%, with HIPSred for energies ≤ 20 keV and PLAorange for energies > 20 keV. The kidney exhibits compatibility with Tough throughout all energy levels, with percentage discrepancies constantly remaining below 1% at 15 and 60 keV. The liver tissue reliably matches with Tough, with variations between 0.5% and 19.4% throughout energy range. Also, adipose tissue is better represented by ABSgrey at 15 keV (0.2%), while TPU aligns with adipose tissue between 2.2%–2.6% at higher energies (20 - 60 keV).
Conclusion: The findings of this investigation indicate that the use of minimum Euclidean distance can identify the most suitable 3D printer material for a specific energy range of interest, supporting researchers in selecting materials for phantom development and facilitating evidence-based decision-making in the design of tissue-mimicking phantoms.