TOMOSYNTHESIS COLLIMATION

A radiographic imaging apparatus having a detector, a radiation source array, and a control processor is configurable to individually energize the radiation sources. A collimator having a number of apertures is movable to either a first or second position in a path of the radiation source array. In one position, the apertures are aligned with a first subset of the radiation sources. In another position, the apertures are aligned with a second subset of the radiation sources. The second subset of the radiation sources define substantially the same radiation field that is defined by the first subset of the radiation sources. A transport apparatus translates the collimator member between at least the first and second positions according to an electronic instruction.