Abstract: A method and an apparatus are provided that enable x-ray projection data acquired by a tomosynthesis system to be transformed into a form as if it had been acquired by a computed tomography (CT) detector. As the x-ray projection data is acquired by a tomosynthesis detector of the tomosynthesis system, the projection data is projected onto a virtual CT detector. The transformed data is then processed to associate virtual pixels of the virtual CT detector with coordinates on the tomosynthesis detector. The intensity values of the pixels of the tomosynthesis detector are then used to interpolate the intensity values of the corresponding virtual pixels of the virtual CT detector. The intensity values of the virtual pixels of the virtual CT detector may then be processed in accordance with a CT reconstruction algorithm to reconstruct the image.