Fabrication and CT Number Measurements of Bone Equivalent Phantom Material Made of Gypsum Material

Abstract

Two types of gypsum materials were used to fabricate five different samples based on the ratio of gypsum powder to water (70%, 65%, 60%, 55%, and 50%) and named as (S1, S2, S3, S4, and S5) for Saudi gypsum and (F1, F2, F3, F4, and F5) for French gypsum. The measured density of samples was in the range of 1.21–1.78 g/cm3, which is in the range of human bone density. A CT scanner was used to investigate the CT number values in the fabricated samples. The CT number results of gypsum samples were in the range of 796.30–1304.07 HU, while the average CT number results for samples S5 and F3 were within the obtained range for human bone tissue. Therefore, the fabricated gypsum sample showed potential to be used as a bone phantom material. In addition, the linear and mass attenuation coefficients μ/ρ, of fabricated gypsum samples were calculated in the CT scan photon energy range of 38 keV. The μ/ρ results showed it is closer to the results of the IBI inner bone material with a range of percentage difference (1.40%–9.48%). This indicates that a CT scan has the capability to measure the attenuation property at a specific diagnostic energy.