Density conversion factor determined using a cone-beam computed tomography unit NewTom QR-DVT 9000

Abstract

Objective: The purpose of this study was to determine a conversion coefficient for Hounsfield Units (HU) to material density (g cm⁻³) obtained from cone-beam computed tomography (CBCT-NewTom QR-DVT 9000) data. Methods: Six cylindrical models of materials with different densities were made and scanned using the NewTom QR-DVT 9000 Volume Scanner. The raw data were converted into DICOM format and analysed using Merge eFilm and AMIRA to determine the HU of different areas of the models. Results: There was no significant difference (P=0.846) between the HU given by each piece of software. A linear regression was performed using the density, ρ (g cm⁻³), as the dependent variable in terms of the HU (H). The regression equation obtained was ρ=0.002H−0.381 with an R² value of 0.986. The standard error of the estimation is 27.104 HU in the case of the Hounsfield Units and 0.064 g cm⁻³ in the case of density. Conclusion: CBCT provides an effective option for determination of material density expressed as Hounsfield Units.