Digital tomosynthesis is an imaging method in which multiple X-ray images are taken of a stationary, compressed, breast. Each image is taken at a slightly different angle, producing a series of 'slices' that can be viewed individually or one after another as a kind of movie. This technique allows clinicians to get a more three dimensional view of the breast being examined and provides more information than a standard mammogram.(1)(2)(3)
An animation depicting digital tomosynthesis of a breast is shown below:
More information on this topic may be found in Chapter 16 of The Biology of Cancer by Robert A. Weinberg.