Breast cancer is the leading cause of cancer among women in the United States. It has always been the hope that devising methods of earlier detection would lead to improvement of long-term survival. Therefore, the development of novel, more selective, and noninvasive diagnostic techniques is a priority. Mammography is currently the most commonly used breast imaging modality for both screening and diagnostic purposes. Additionally, breast ultrasound imaging and breast magnetic resonance imaging (MRI) are generally used to supplement or help confirm any indeterminate or suspicious finding prior to consideration of a breast biopsy. However, these conventional imaging methods lack information about tissue function and have lower diagnostic accuracy.