 All study participants will be helping us evaluate a specific use for the FDA approved ABUS system: screening women with dense breasts. If ABUS is proven to improve early breast cancer detection rates in women with dense breast tissue, the standard of care for breast screening may change so that all women with dense breast tissue may receive ABUS as part of standard care in addition to screening mammography, and will reduce the number of women who die from breast cancer every year. If no improvement in breast cancer is proven, the standard of care will not change and future patients and doctors will benefit from the knowledge that routine screening mammography is the most effective program for early breast cancer detection. 