 Study Design: This is a prospective matched-pair clinical study enrolling more than 20,000 women with parenchymal density 50 on digital x-ray mammography XRM. Participants will receive ABUS as an adjunct to XRM. Any abnormal findings, from either XRM or ABUS, will receive appropriate management action consistent with accepted medical standards of care. All evaluation results, diagnosis and treatment outcomes will be recorded. Participants will be followed for one year and those who are not diagnosed with breast cancer at enrollment or during the follow-up interval must undergo an annual mammogram at study completion, the outcome of which will be recorded. 