Physical realization of a mesh-based 3D head phantom derived from ICRP publication 145 reference computational phantom

초록

This study developed and evaluated a dual-material physical head phantom based on the adult male Mesh-type Reference Computational Phantom (MRCP) from International Commission on Radiological Protection (ICRP) Publication 145. PLA+ and Magarita bone filaments were selected as candidate materials for the soft tissueequivalent and skull-equivalent regions, respectively, and their radiological characteristics were assessed using elemental composition, effective atomic number (Zeff), normalized mass attenuation coefficient (mu/rho), and CTderived effective density (rho eff) analysis. X-ray fluorescence (XRF)-based elemental analysis provided detectable elemental information for the filaments, while an additional pure PLA reference calculation was used to support the interpretation of PLA + as a polymer-based soft-tissue-equivalent material. The HU-rho eff assessment confirmed that printed PLA + exhibited low-attenuation CT characteristics consistent with the intended soft tissueequivalent domain, whereas Magarita bone showed higher attenuation characteristics suitable for the skullequivalent domain. Based on these material evaluations, the adult male MRCP head geometry was converted into a dual-material fused filament fabrication (FFF) 3D-printed phantom. CT evaluation demonstrated preservation of the overall head contour, structural continuity, and clear separation between the skull-equivalent and soft-tissue-equivalent regions. ROI-based HU analysis showed that the fabricated MRCP-based phantom reproduced the principal skull to soft-tissue CT attenuation contrast observed in a RANDO anthropomorphic head phantom. These findings indicate that standardized MRCP anatomy can be physically realized as a CT-evaluable anthropomorphic phantom with distinguishable material domains.

키워드