FABRICATION AND CHARACTERIZATION OF AN OLIVE TREE TRUNK-BASED HUMAN TISSUE-EQUIVALENT PHANTOM FOR COMPUTED TOMOGRAPHY (CT) SCAN APPLICATIONS

Abstract

This thesis investigates the potential of olive wood (Olea europaea) as a sustainable and cost-effective tissue-equivalent phantom material for computed tomography (CT). Phantoms are essential in medical imaging and dosimetry as they provide a reproducible substitute for human tissues, enabling accurate calibration, quality assurance, and training applications. Conventional phantom materials, such as water, Polymethyl methacrylate (PMMA), epoxy compounds, and tropical woods like Rhizophora spp., have proven useful but remain limited by cost, availability, mechanical stability, or environmental concerns. Against this backdrop, the study explores olive wood, a dense Mediterranean hardwood, which has received little radiological characterization despite its promising physical and mechanical properties. A multidisciplinary experimental approach was adopted, encompassing physical, radiological, and elemental analyses. Olive wood samples were prepared under controlled conditions and examined for density, equilibrium moisture content (EMC), and mechanical uniformity. Radiological characterization involved determination of the Hounsfield Units (HU) on the basis of CT imaging, calculation of the effective atomic number (Zeff) and mass attenuation coefficients (μ/ρ) based on elemental composition and theoretical modeling. The compositional data was obtained by X-ray fluorescence (XRF) spectroscopy for the elements that could be detected and the Elemental Similarity Index (ESI) was calculated based on the compositional data. Results demonstrated that olive wood exhibits mass density values within 0.906–0.924 g/cm³, within an acceptable range for selected soft-tissue simulation. Equilibrium moisture content stabilized at ~4.7%, suggesting improved measurement stability radiological consistency. The mean HU values (~30 ± 1.4) positioned olive wood within the general soft-tissue CT range, while its Zeff (~7.48) and ESI (~0.96) indicated elemental similarity to biological tissues. Additionally, theoretical μ/ρ values showed compatibility with reference phantoms, reinforcing its radiological adequacy. The findings confirm that olive wood is promising CT phantom material for preliminary QA and educational applications. Its advantages include accessibility in Mediterranean regions, machinability, biodegradability, and ecological sustainability. Therefore, olive wood emerges as a potential low-cost alternative that requires further validation, particularly in low-resource medical and educational settings, where affordability and local availability are critical. By establishing its physical and radiological equivalence, this work contributes to the broader pursuit of sustainable phantom libraries, fostering innovation in diagnostic imaging, The study for CT future dosimetric studies, and medical training.