US Patent 8031834 Tomosynthesis apparatus and method to operate a tomosynthesis apparatus

A tomosynthesis apparatus has an x-ray source that generates an x-ray beam emanating from a focus, which is received by a flat panel detector. To set a tomosynthesis angle, the position of the central axis of the x-ray beam of the x-ray source is variable. A collimator diaphragm has a diaphragm aperture that limits the expansion of the x-ray beam at the location of the flat panel detector. The collimator diaphragm is arranged in the beam path between the focus and the flat panel detector. The shape and size of the diaphragm aperture are dynamically varied (adjusted) dependent on the changing tomosynthesis angle, such that the expansion of the x-ray beam at the location of the flat panel detector always essentially corresponds to the detector dimensions.