1. A volumetric imaging device for constructing a three dimensional image of an object, the volumetric imaging device comprising: a source comprising: a photon source; and a scatter detector arranged between the object and the photon source, wherein the photon source emits photons towards the scatter detector, the scatter detector scattering at least some of the photons and detecting the scattered photons, the object scattering at least some of the photons; an absorbing detector arranged to detect scattered photons from the object; and an image constructor for constructing the three dimensional image based on the scattered photons.