 Finding breast cancer early has been shown to improve the chance of survival. Mammography x-ray imaging of the breast helps find breast cancer early. Some breast cancers, however, are not seen on mammography, which creates two-dimensional images for the radiologist to see. The goal of this study is to make a breast tomosynthesis or tomosynthesis 3D three-dimensional x-ray system by taking x-ray images from many angles. This is similar to a CAT computerized axial tomography scan for the breast and can give radiologists 3D information so that they can find breast cancers which might otherwise be hidden from view. 