We are investigating, both theoretically and experimentally, the application of dual-energy techniques to the detection of calcifications in mammography. A prototype xenon ionization detector, developed for scanned projection digital radiography, is used to obtain images at two energies. These image pairs are processed to produce pairs of "material" images which give the equivalent thicknesses of lucite and aluminum of the imaged objects. The material images are then combined such that the final image has minimal soft-tissue contrast. When this has been done, calcifications may be more easily visualized due to the removal of soft-tissue background "clutter," despite increased image noise. The dual-energy procedure is described and experimental images of a phantom and breast tissue are presented.
|