Large Area Digital Imaging System for Mammography

In mammography, early detection of breast cancer is dependent upon the ability of the imagingsystem to resolve characteristic distributions and shapes of small microcalcifications in the breast tissue,since approximately 80% of excised breast cancers show areas of calcification on histologicexamination. The medical community has not been satisfied with the imaging performance of standardfilm-screen in its ability to produce the required quality images. Recently, there has been a desire toresolve 50 micromoles structures with very high detection efficiency. This technique would allow a veryhigh spatial resolution, superior to slow film-screen, with an efficiency greater than fast film-screen. Amicrostructured scintillator film would allow images to be obtained with a lower dose than film-screen,while the digital nature of the image would permit a wide dynamic range as well as the possibility ofimage enhancement. The use of a modified low noise amorphous silicon (a-Si:H) detector technologywhich takes advantage of the high scintillator light output will permit high quality digital imaging systemsof 3Ocm x 3Ocm, comparable in area to film-based systems, and much larger than conventionaltechnology currently employed in commercial digital imaging systems. The research would enable thedevelopment of an initial prototype of such a high performance mammographic imaging system.Specifically, we will develop large-area high resolution structured scintillator screens and low-noisea-Si:H detectors needed to carry out this objective.