1. A system for reconstructing a 3D volume, comprising: a surface acquisition apparatus comprising a light source, a scanner, and an image sensor to generate a 3D surface contour characterization of a patient; an X-ray imaging system for acquiring 2D X-ray projection data of the patient from a plurality of angular positions; a controller programmed with instructions to synchronize the 3D surface contour characterization from the surface acquisition apparatus with the acquired 2D X-ray projection data; and a processor comprising a motion reduction algorithm that uses the acquired 2D X-ray projection data and the generated 3D surface contour characterization to reconstruct a 3D volume, and a motion correction reconstruction algorithm applied to the reconstructed 3D volume to generate a motion corrected reconstructed 3D volume.