If digital breast tomosynthesis (DBT) is performed on the basis of an abnormal screening mammogram, then the sensitivity of DBT cannot exceed that of mammography. This topical review on digital breast tomosynthesis (DBT) is provided with the intent of describing the state of the art in terms of technology, results from recent clinical studies, advanced applications, and ongoing efforts to develop multimodality imaging systems that include DBT. Particular emphasis is placed on clinical studies. The observations of increase in cancer detection rates, particularly for invasive cancers, and the reduction in false-positive rates with DBT in prospective trials indicate its benefit for breast cancer screening. Retrospective multireader multicase studies show either noninferiority or superiority of DBT compared with mammography. Methods to curtail radiation dose are of importance.© RSNA, 2015

Tomosynthesis of the breast is currently a topic of intense interest as a logical next step in the evolution of digital mammography. This study reports on the computation of glandular radiation dose in digital tomosynthesis of the breast. Previously, glandular dose estimations in tomosynthesis have been performed using data from studies of radiation dose in conventional planar mammography. This study evaluates, using Monte Carlo methods, the normalized glandular dose to the breast during a tomosynthesis study, and characterizes its dependence on breast size, tissue composition, and x‐ray spectrum. The conditions during digital tomosynthesis imaging of the breast were simulated using a computer program based on the Geant4 toolkit. With the use of simulated breasts of varying size, thickness and tissue composition, the to the breast tissue was computed for varying x‐ray spectra and tomosynthesis projection angle. Tomosynthesis projections centered about both the cranio‐caudal (CC) and medio‐lateral oblique (MLO) views were simulated. For each projection angle, the ratio of the glandular dose for that projection to the glandular dose for the zero degree projection was computed. This ratio was denoted the relative glandular dose (RGD) coefficient, and its variation under different imaging parameters was analyzed. Within mammographic energies, the RGD was found to have a weak dependence on glandular fraction and x‐ray spectrum for both views. A substantial dependence on breast size and thickness was found for the MLO view, and to a lesser extent for the CC view. Although RGD values deviate substantially from unity as a function of projection angle, the RGD averaged over all projections in a complete tomosynthesis study varies from 0.91 to 1.01. The RGD results were fit to mathematical functions and the resulting equations are provided.

Purpose: To prospectively determine the radiation dose to the organs of the body during standard bilateral two-view mammography by using Monte Carlo simulations and a phantom. Materials and Methods: A modified version of the Cristy mathematic anthropomorphic phantom was implemented in the Geant4 Monte Carlo tool kit to simulate the conditions present in screen-film and digital mammography. The breast was simulated with compression in both the craniocaudal and the mediolateral oblique views. X-rays were tracked from the source until their absorption in the body or in the detector or their exit from the simulation limits, with recording of all the intermediate interactions in the body. The simulation was performed with x-rays of energy ranging from 6 to 35 keV to obtain results for clinically relevant spectra. The ratio of dose to an organ in the body per unit glandular dose to the breast, denoted the relative organ dose (ROD), was computed. The effect of using a body protective shield was also investigated...