Mammography is currently the best imaging technique for the early detection and diagnosis of breast cancer. Although numerous advances and improvements in mammography in the past decades have greatly improved image quality, the technique is not without shortcomings that limit its sensitivity and specificity. Multiple areas of research have therefore been sought not only to improve film/screen mammography, but also to consider entirely new techniques in the study of breast cancer. Although this review is not intended to include all methods currently under investigation, those chosen for discussion represent areas where major efforts have provided data that suggest exciting future applications. These include MR imaging, digital mammography, computer-aided diagnosis (CAD), positron-emission tomography (PET), and single-photon emission planar CT imaging (SPECT).