Development of a novel anthropomorphic bone phantoms for mimicking osteoporosis in medical imaging development.

Abstract

Osteoporosis (OP) is characterised by loss of bone mineral density (BMD) and deterioration of trabecular microarchitecture, yet routine clinical imaging techniques remain limited in their ability to fully characterise bone microarchitecture. As new imaging technologies are developed, the potential for point of care bone assessment with both density and microarchitectural parameters of bone becomes a reality. Although advanced imaging modalities such as high-resolution peripheral quantitative computed tomography (HR-pQCT) offers improved sensitivity to bone structure, this is primarily focused on research settings. The development of higher resolution digital tomosynthesis (DT), required rethinking of phantoms, otherwise development and pre-clinical validation are constrained by the lack of reproducible, structure-controlled reference standards. In this study, we present a novel anthropomorphic bone phantom designed as a preclinical platform for calibration, benchmarking, and validation of bone imaging systems and quantitative analysis methods. The phantom integrates digital-twin trabecular models derived from micro-computed tomography (μ-CT), enabling parametric control of trabecular thickness and bone volume fraction to represent healthy and osteoporotic conditions. BMD is independently controlled using calibrated contrast agent (PVP-BaSO₄), while moulded lean and adipose soft-tissue equivalents are incorporated to provide realistic X-ray attenuation for projection-based imaging. The phantoms were evaluated using multiple imaging modalities, including X-ray, DXA, pQCT, DT, and μCT, to verify their fidelity in reproducing both BMD and trabecular microstructural features. Imaging-derived parameters showed strong correlations with controlled variations in trabecular architecture and BMD, demonstrating the utility of the phantom as a source of controlled ground truth for cross-modality comparison. This reproducible platform enables systematic evaluation of imaging systems and facilitates early osteoporosis detection by bridging structure-density relationships. Our phantom serves as a valuable tool for preclinical diagnostic validation, imaging quality assurance, and the development of bone health biomarkers, thereby reducing reliance on animal or cadaveric studies.