Figure 5.

Technique for virtual monochromatic imaging on a benchtop cone beam computed tomography (CBCT) unit. (A) Region of interest (ROI) used for contrast-to-noise ratios (CNR) calculation. (B) CatPhan phantom axial slice reconstructions at kV, MV, and virtual monochromatic energies 30 keV through to 2 MeV. (C) Axial CBCTs of titanium-BB phantom at 125 kVp and virtual monochromatic 100 keV and corresponding HU of artifact and background. (D) Virtual monochromatic CBCTs of the water phantom containing 2 iodine concentrations at different keVs: 30 to 150 keV and LE (80 kVp) and HE (150 kVp). The corresponding CNR curves for the 2 iodine concentrations and the reduction in beam hardening artifact are shown on the curves beneath as a function of keV. (A-B) Adapted with permission from reference Li et al³⁴ (C-D) Adapted with permission from reference Li et al.⁴²