Some aspects include acquisition of a first plurality of projection images of a volume using a megavoltage x-ray source, each of the first plurality of projection images associated with a respective one of a first plurality of locations of the megavoltage x-ray source, acquisition of a second plurality of projection images of the volume using a kilovoltage x-ray source, each of the second plurality of projection images associated with a respective one of a second plurality of locations of the kilovoltage x-ray source, and performance of digital tomosynthesis reconstruction to generate a three-dimensional image of the volume based on the first plurality of projection images and the second plurality of projection images. The first axis may be perpendicular to the second axis.