The accuracy of a medical imaging examination depends on both the quality of the image acquisition and the quality of the image interpretation. For more than half a century, computer technology greatly improved image acquisition systems, e.g., with the development of various advanced tomographic imaging modalities. Computer technology is also contributing to the quality of the image interpretation process by incorporation of CAD, i.e., computer-aided detection (CADe) and computer-aided diagnosis (CADx). CADe involves the use of computer analyses to indicate locations of suspect regions in a medical image. The characterization, diagnosis, and patient management are left to the radiologist. CADx involves the use of computer analyses to characterize a region or lesion, initially located by either a human or computer, leaving the final diagnosis and patient management to the radiologist. We present here our progress in CADx for breast cancer using mammography, sonography, and breast MRI.