Assessment of physical phantoms produced in the PHENOMENO project utilizing three fused filament fabrication approaches

Introduction: The aim of this study was to evaluate the suitability of three approaches in producing physical breast phantoms using the low-cost 3D printing fused filament fabrication (FFF) technique. Methods: Three physical phantoms were produced: the first (PB1) is based on PLA filament extruded with different extrusion rates and constant printing speed; the second (PB2) and third (PB3) were each printed with two filaments: ABS-ASA for PB2 and HIPS-ASA for PB3. The phantoms were scanned using a clinical CT facility at different kilovoltage (kV) settings. Objective analysis comprised power spectrum, fractal dimensions, histogram metrics (skewness, kurtosis), and Hounsfield Unit (HU) values. Experienced radiologists performed a subjective assessment. Results: All phantoms demonstrated β indexes in the range of 1.39–2.72, with PB2 showing the lowest values. The measured HU values for the breast tissues as a whole increased with increasing kV. PB1 showed very good results in terms of measured HU values for glandular tissue, skin, and adipose tissue. In PB2, ABS proved to be well suited for representing adipose tissue, whereas HIPS exhibited lower than expected HU values. Similarly, in PB3, ASA showed HU values that were lower than those reported in the literature. These discrepancies highlight the need for further optimization of printing parameters for HIPS and ASA materials. Subjective evaluation revealed no significant differences in the visual quality of the phantoms. Conclusions: FFF printing challenges hinder widespread anthropomorphic phantom production. Further research is needed for dual-material printing.