Dose 2016

Some developments: DECT

Attenuation is function of medium density and elemental composition Several materials same HU but different densities and elemental compositions

DECT exploits energy and compositional dependence of µ at keV energies µ (E) = ρ (af compton (E) + bf PE (E)) a and b depend only on composition of material

Scan at 2 energies to give Z eff via simultaneous equations

and electron or mass density